Xenon and Cooling Therapy in Babies at High Risk of Brain Injury Following Poor Condition at Birth: A Randomised Pilot Study
Phase: PHASE1
Conditions: Hypoxic Ischaemic Encephalopathy
Sponsor: University Hospitals Bristol and Weston NHS Foundation Trust

 
 
 
Neonatal Xenon Breathing  Study. St. Michael’s Hospital, Bristol 
 
 
 
 
CLINICAL STUDY PROTOCOL 
 
 
 
 
 
 
MHRA STUDY REFERENCE NUMBER: CI/2011/0061 
 
REC Reference Number: 12/SW/0010 
CH/2011/3799 
 
 
XENON AND COOLING THERAPY IN BABIES AT HIGH RISK OF  
BRAIN INJURY FOLLOWING POOR CONDITION AT BIRTH: RANDOMISED PILOT STUDY 
(COOLXENON2 STUDY) 
 
 
 
  
1 May 2013             Issue 2  Revision 3    
 
 
 
 
Study Sponsor: 
 
Research and Innovation, Level 3 
UH Bristol Education Centre 
Upper Maudlin Street 
Bristol   BS2 8AE 
Tel: 0117 342 0233 
 
 
 
 
 
 
 
The information in this document is confidential and is the property of University Hospitals Bristol NHS 
Foundation Trust. The information may be provided only to Investigators, Co-Investigators, appropriate trial 
personnel, members of the Research Ethics Committee and personnel of the authorities to which it is 
submitted. This protocol may not be photocopied or discussed with third parties not involved in the clinical 
study without prior written authorisation from University Hospitals Bristol NHS Foundation Trust. 
 
 
 
 
 

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Confidentiality Statement 
 
The confidential information in the following document is provided to you as an Investigator, potential 
Investigator, or Consultant for review by you, your staff and an appropriate Independent Ethics Committee.  
By accepting the document you agree that the information contained herein will not be disclosed to others 
without written authorisation from University Hospitals Bristol NHS Foundation Trust except to the extent 
necessary to obtain informed consent from those persons to whom the products may be administered. 
 
 
 
 
 
 
 
 
 
 
 
 
 

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Protocol Summary 
Title 
XENON AND COOLING THERAPY IN BABIES AT HIGH RISK OF  
BRAIN INJURY FOLLOWING POOR CONDITION AT BIRTH: 
RANDOMISED PILOT STUDY 
(COOLXENON2 STUDY) 
Investigators 
Professor Marianne Thoresen (Chief Investigator) 
e-mail: marianne.thoresen@bristol.ac.uk Mob: 078882 11052 
Dr John Dingley (Co-Investigator) 
e-mail: JohnDingley98@gmail.com  Mob: 07735 379471 
Dr James Tooley (Co-Investigator) 
e-mail: james.tooley@bristol.ac.uk  Mob: 07973 883572 
Dr Ela Chakkarapani (Co-Investigator) 
Dr Hemmen Sabir (Co-Investigator) 
Dr David Windsor (Co-Investigator) 
Dr Hannah Gill (Co-Investigator) 
Dr Elisa Smit (Co-Investigator) 
Sally Jary (Co-Investigator) 
Dr Frances Cowan (Co-investigator) 
Study Centre 
St Michael’s Hospital 
Southwell Street 
Bristol 
BS2 8EG 
Test Article 
Xenon Neonatal Breathing Device  
Objectives 
Primary Objective:  
This is a randomised two group pilot study comparing;  
i) xenon inhalation for 18 hours in combination with whole body 
cooling to 33.5 °C for 3 days, to  
ii) the established treatment of cooling the body down to 33.5 °C 
for 3 days.  
 
This will be applied in term newborn babies who are at moderate or 
high risk of brain injury following poor condition around the time of 
birth. 
 
 
Our hypothesis is that during the first 2 weeks after birth using a 
combination of validated (in our own and others cohorts) early 
predictors of outcome we may observe an enhanced neuroprotective 
effect of the xenon-cooling combination over cooling alone and this 
will allow us to perform power calculations for a larger definitive 
neurological outcomes study of otherwise similar design. 
 
Outcome predictors are based on a combination of: 
1) Time in hours after birth when background activity as recorded by 
amplitude integrated EEG (aEEG: from single channel EEG) [1] and 

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onset of sleep wave cycling (SWC). Time to Normal trace and SWC 
are both very good (PPV>90%) outcome predictors 
2) MRI before 2 weeks of age (T1W and T2W) has a PPV of 84% in 
cooled infants in the TOBY trial in which we were a major recruiting 
centre [2] Resistance Index (RI) was not a definite predictor for 
cooled infants [3]). We will do the examination but not use it in the 
prediction. Peak value of Lactate Dehydrogenase within the first 
72h of life [4, and Thoresen M 2012 submitted ]. 
 
 
 
Secondary Objectives:  
 We will monitor a number of variables before/during and after the 
period of xenon delivery. This group of physiological and biochemical 
parameters includes those recorded during our recently completed 
xenon+cooling feasibility/safety study in neonates and a few more are 
added .  
They are: 
  
Gas exchange: Transcutaneous oxygen saturation, end-tidal carbon 
dioxide concentration, blood gas data (from arterial sample), 
mechanical ventilation requirements (rate, peak inspiratory pressure, 
PEEP settings).  
 
Haemodynamic: Systolic, mean and diastolic arterial pressure, heart 
rate. 
 
Any problems during weaning and extubation, such as post-extubation 
stridor, use of steroids. 
 
We have also looked at other variables in the infants cooled in our 
hospital (inborn or outborn) ca 30/year since 1/12/06. We chose the 
best matched controls (3:1) from this cooling database and compared 
them with the 14 infants in the recent Xenon + cooling human 
feasibility study (the precursor to this study),  
We will also record: 
1] Coagulopathy [INR >2, APTT> 50] 
2] Inotrope requirement, cardiac Troponin T 
3] Hepatic impairment, [raised Alanine aminotransferase > 40, Alkaline 
phosphatase > 100, peak Lactate dehydrogenase within 72h of age 
4] Renal impairment, oliguria [urine output < 1 ml/kg/h after day 1 of 
life and  raised creatinine > 100] 
5] Infection [culture proven, need for antibiotics > 5 days, raised CRP ~ 
within  the first 24h  and at 4 days of life of life] 
6] Number of anticonvulsive drugs needed to treat seizures 
7] Length of hospital stay 
8] Time to full oral feed by bottle or breast  
9] MRI assessment by T1 and T2 weighted images using the scoring 
system by Rutherford et al [2]. 
10] In some infants when the 3Tesla MRI scanner is available 
assessment of brain metabolites using magnetic resonance  
spectroscopy (MRS) where the ratio Lactate/N-acetyl aspartate has 

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been shown to be a good early biomarker for outcome [5]. 
 
Safety 
Patient Population 
Newborn infants >/=36 weeks gestation which satisfy all St Michael’s 
Hospital standard inclusion criteria for cooling (i.e. at risk of brain 
injury following poor condition at birth) and which additionally satisfy 
the inclusion criteria of this investigation for the administration of 
xenon by inhalation. Cooling should be started within 3h of age and 
xenon within 5. Use of a shorter treatment delay in these entry criteria 
will optimize the possibility of finding an effect if there is one.  
Population Size 
16 babies in each of 2 groups 
Structure 
Single centre prospective randomised clinical pilot study 
 
Duration of Participation 
Xenon administration period of 18 hours. Recruitment period up to 18 
months from start of study. Short and long term monitoring until 18 
months of age. Therefore total study duration 3 years. 
Method of Assignment 
Comparative study. Neonates meeting all entry criteria can be 
included. 
Randomisation 
Patients will be randomised between cooling (standard treatment) and 
xenon+cooling groups as this is a comparative study. Patients will be 
randomised on a 1:1 basis to receive either conventional cooling 
therapy or cooling plus xenon therapy. 
Statistical Analysis 
This is a randomised pilot study. Data presentation will include 
descriptive statistics only. These will be compared in the 2 treatment 
groups but also to recordings of the same variables in a similar group 
of 45 infants (recruited to cooling only from the same entry criteria) 
recently treated in our department (historical control data). 
Differences between the groups will be estimated. 
Sample size is 16 infants in each group. In accordance with the paper 
by Julious (Appendix 11), 12 is a large enough number to estimate the 
mean value of short term outcome variables  for the group. The study 
does of course not have the power to test outcome. The main purpose 
of this randomised pilot study is to examine whether early recruitment  
is feasible, secondly whether the short term biological markers show 
the expected range  of values  in the cooled only group as compared to 
our historical controls.  Our advisory statistician for this study is 
Professor Lars Walloe who also advised all our experimental xenon 
work as well as the recent clinical feasibility study.  
 
By April 2013 we have recruited 8 babies to standard cooling therapy 
and 7 babies to xenon plus cooling; we have failed to recruit 
approximately the same number due to failure to commence xenon 
delivery at St Michael’s Hospital within 5 hours of birth. This is due to 
the time it takes to retrieve infants from the regional hospitals. Since 
April 2013, our xenon delivery system has been transportable and we 
have so far successfully started xenon treatment on two babies in the 

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local hospital and transferred them to St Michael’s Hospital while 
xenon was being delivered en route. This ability to commence xenon 
at the referring trust enabled us to recruit consecutive infants that 
would otherwise have been missed.  We wish to assess the feasibility 
of recruiting now we have xenon in the ambulance by increasing the 
number of babies by 8. 
Adverse Events 
Volunteered and Elicited 

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SECTION 
CONTENTS 
 
PAGE 
 
Confidentiality Statement 
2 
 
Protocol Summary 
3 
 
Overview 
9 
1.0 
Background and Introduction 
9 
1.1 
Background 
9 
1.2 
 
Review of Literature  
9 
1.3 
Rationale for the Study 
10 
2.0 
Objectives 
11 
2.1 
Primary Endpoint 
11 
2.2 
Secondary Endpoint 
12 
3.0 
Study Design 
13 
3.1 
Study design and procedures 
15 
3.2 
Follow up 
22 
3.3 
Justification of Design 
23 
3.4 
Justification of Treatment/Procedure 
23 
4.0 
Study Therapies 
24 
4.1 
Test Article: Description 
24 
4.2 
Principles of Operation 
24 
4.3 
Clinical Development 
27 
4.4 
Regulatory Status 
28 
4.5 
Packaging and Labelling 
28 
4.6 
Component Tracking 
28 
4.7 
Control/Comparator Therapy 
28 
5.0 
Patient Selection 
28 
5.1 
Inclusion Criteria 
29 

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5.2 
Exclusion Criteria 
30 
5.3 
Prohibited Therapies 
31 
6.0 
Subject Assignment to Treatment Group 
31 
7.0 
Methods and Procedures 
31 
7.1 
Informed Consent 
31 
7.2 
Pre-Study 
32 
7.3 
Screening 
32 
7.4 
Initial Assessment 
32 
7.5 
Study Phases 
33 
7.6 
Study Data 
34 
8.0 
Assessment of Safety 
35 
8.1 
Data Review Group 
35 
8.2 
Composition of Data Review Group 
35 
8.3 
Criteria for stopping the study 
37 
8.4 
Adverse events (AE’s) 
38 
8.5 
AE Definitions 
38 
8.6 
AE Classification 
39 
8.7 
AE Recording 
39 
8.8 
AE Reporting 
39 
8.9 
Reporting Responsibilities to Regulatory Authorities, Investigators and Ethics Committees 
39 
9.0 
Data Analysis and Statistical Plan 
39 
9.1 
Statistical Analysis 
39 
9.2 
Interim analysis and stopping rules 
39 
10.0 
Withdrawal of Subjects from Study 
39 
11.0 
Modification of Protocol 
40 
12.0 
Discontinuation of Study 
40 

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13.0 
Administrative Requirements, Ethical and Regulatory Aspects and Quality 
Assurance 
40 
13.1 
Study Approvals: MHRA, Research Ethics Committee (REC) and NHS Trust R&D Approval 
40 
13.2 
Responsibilities of the Investigator 
40 
13.3 
Subject Information 
40 
13.4 
Subject Consent 
40 
13.5 
Source Data and Subject Files 
40 
13.6 
Reporting and Recording of Data 
41 
13.7 
Monitoring 
41 
13.8 
On-Site Audits 
41 
13.9 
Record Storage and Retention 
42 
 
 13.10 
Indemnity 
42 
14.0 
Study Sponsor 
42 
15.0 
Publication 
42 
16.0 
References 
43 
APPENDICES 
48 
 
A1: Summary of study procedures 
48 
 
A2: Laboratory technical feasibility study 
49 
 
A3: Pre-clinical outcome data 
59 
 
A4: Data from Human Feasibility Study (CoolXenon) (ended April 2011) 
60 
 
A5: Pre-clinical physiology data and summary 
68 
 
A6: Letter from study statistician 
81 
 
A7: Patient information sheet (Abbreviated and full versions) 
83 
 
A8: Informed consent document 
89 
 
A9: Declaration of Helsinki 
90 
 
A10: Group size discussion for pilot studies (paper) 
93 

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Overview 
The proposed study is planned to be a single centre study at St. Michael’s Hospital Bristol, prospective randomised pilot 
clinical study. It may include Southmead Hospital Bristol at a later stage if recruitment is low. We have included a 
shorter delay for recruitment to optimize the effectiveness of hypothermia and potentially xenon. We will accept 
cooled infants that are <3h old and start xenon within 5h of age. In an experimental study we did not find any 
improvement of adding xenon if both were started at 5 hours after the insult [6], however 2h delayed xenon when HT 
was started immediately was more effective than HT alone [7]. 
  
The study examines the effect of inhaled xenon gas used in the treatment of newborn infants with hypoxic-ischemic 
encephalopathy (HIE), in combination with cooling which is the standard treatment for this condition. The hypothesis is 
that the xenon+cooling combination will produce better neuroprotection than the standard treatment, cooling, alone. 
Xenon, a rare anaesthetic gas, is almost side-effect free and shows great promise as a method of enhancing the 
neuroprotection offered by cooling. It is, however, extremely expensive at £25-50/L. 
 
We propose to study 32 full term infants with moderate or severe HIE who, on clinical grounds, require mechanical 
ventilation and hypothermia for 72 hours. The hypothermia (cooling) will be routinely applied if the standard existing 
criteria for this are met except recruitment needs to be earlier, <3h rather than 6h as noted above. Candidates for the 
study will be randomly assigned to one of two groups: (i) the standard treatment for this condition, 72 hours of cooling, 
i.e. the treatment they are already receiving, or (ii) addition of 50% xenon concentration in the breathing gas from the 
mechanical ventilator for 18 hours in combination with the existing cooling regime, the cooling then continuing to 72 
hours. All efforts will be made to commence delivery of the xenon and cooling as soon as possible after birth, with 
maximum delay of 5 hours for xenon and 3 hours for cooling. Xenon will be given in the breathing gas mixture via a 
special delivery system situated between the ventilator and airway of the infant. This device has been specifically 
developed to eliminate xenon wastage [8], without which this putative therapy would be completely unfeasible on cost 
grounds. It has recently been successfully used in 14 babies with the same entry criteria in our recent MHRA approved 
human feasibility/safety study [9]. Meetings of an independent Data Review Group will take place after the recruitment 
of every 4th baby during enrolment of infants to the xenon+cooling group. 
 
1.0 
Background and Introduction 
1.1 
Background 
HIE is a major cause of severe cognitive and motor disability in term infants. Until 2005, there was no effective 
treatment for HIE. Since 1993 we have developed moderate hypothermia (HT) as a neuroprotective treatment 
culminating in a successful clinical feasibility study in Bristol 1998-9 (10 infants). This experimental work led to the 
“CoolCap” trial [10] followed by the UK “TOBY” trial.[11] In both trials Bristol was a major recruiting centre (PI:MT). The 
trials have shown that HT significantly reduced disability and cooling has now become standard treatment.  Because the 
protection from clinically delayed HT (by 4.5h) is only partial, (absolute risk reduction 15% [12], enhancing its 
effectiveness as well as starting earlier is paramount. More recent clinical trials have also shown effectiveness of HT 
[13]. Since 2003 we have demonstrated that immediate xenon and immediate hypothermia in combination, increase 
cerebral protection from 35% (HT alone) to 70% in newborn rats and pigs.[14, 15] In 2011 we completed a human 
neonatal feasibility/safety study of 14 patients undergoing standard cooling therapy for moderate or severe perinatal 
asphyxia using a xenon delivery system of the same design. We experienced no technical problems due to the breathing 
system or use of the xenon gas (Appendix 4) nor any adverse effects related to these. 
 
1.2 
Review of Literature 
Critical lack of oxygen delivery to the foetus during labour and delivery results in HIE in 1-3 per 1000 births at term.  60-
70% of infants with moderate/severe HIE die or survive with serious disability such as cerebral palsy and/or learning 
difficulties. Some of the survivors are unable to walk, sit up, control head movement, feed or communicate. Until 2005 
there was no treatment that had been shown to improve outcome in such infants. Since 1993 Marianne Thoresen’s 

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group have taken moderate hypothermia (HT) as a neuroprotective treatment through all the steps of therapeutic 
development starting with small (rat)[16,17] and large (pig),[18,19] animal models to a clinical feasibility study in Bristol 
(body or head cooling in 10 infants)[18]. In collaboration with others our experimental work and clinical pilot led to the 
American funded “CoolCap” trial where Bristol was a major recruiting centre. The results were published in 2005 and 
showed a therapeutic benefit from hypothermia.[1] This study was followed by the American National Institute of Child 
Health and Development body cooling trial which also showed reduced mortality and improved neurological outcome 
in the cooled group.[22]  We and colleagues in the UK (PI Denis Azzopardi) received MRC funding to carry out the 
largest of all the cooling trials, the “TOBY” trial recruiting a total of 325 infants. St. Michael’s Hospital was a major 
centre in these trials and MT is one of the principal investigators and grant holders for the TOBY trial.[11] We have 
received further MRC funding to carry out long term follow up of this cohort which is ongoing.  Other trials in Europe 
[23] and Australia (ICE trial) [24] have also shown significant improvement in cooled infants.  
In these 5 big trials [10,11,21-23], HT reduced death or disability from 66% to 51%. The number needed to treat (NNT) 
to prevent death or disability is 9. Hypothermia has also been shown to be effective in adults after cardiac arrest and is 
being considered for other conditions where brain injury is the major problem (e.g. stroke, head trauma). 
At the end of 2006, we finished recruiting to the TOBY trial and HT became standard of care in Bristol. Our local 
incidence of poor outcome in this group has been further reduced to 39% [25] as compared to 48% for the cooled 
group in “TOBY”). Compared to our own historical controls using the same entry criteria where the incidence of poor 
outcome was 63% without active treatment, our Bristol cooling protocol has reduced the relative risk of a poor 
outcome by 38%. Thus HT improves outcome but does only partly abolish death or disability. There is clearly a need to 
explore other therapies that can be combined with HT to further improve outcome in this devastating condition. 
For the past 8 years our research group has been investigating the rare anaesthetic noble gas xenon, which is showing 
great promise as a neuroprotectant in HIE. Despite being considered “noble” because it is almost inert in conventional 
chemical reactions, xenon is not completely inert in biological systems and has been known as an anaesthetic for 
decades. The group has built upon the initial work in cell cultures [26,27] by conducting both small and large animal 
studies of xenon+cooling with positive results. In particular a suitable delivery and monitoring system capable of 
providing xenon to the inhaled gas mixture of a mechanically ventilated infant in the neonatal intensive care unit has 
been developed and evaluated in a pig model of global HIE – replicating the clinical scenario in pigs of similar weight to 
human neonates. This has been developed by Dr John Dingley, Reader in Anaesthetics, a member of the Thoresen 
collaborative group and honorary consultant at University Hospital Bristol. 
The group have recently used this system in the first human neonatal feasibility/safety trial of xenon + cooling in this 
group of neonates, which was carried out in Bristol over 12 months and successfully completed  05/04/2011  (Appendix 
4). 
We add a recent, relevant paper [48] by Sabir et al which illustrates the safety of xenon.  There was no increased 
apoptosis after breathing xenon for 24 hours, as compared to a 10x increase breathing isofluorane. 
 
1.3 
Rationale for the Study 
We have undertaken a series of experiments since 2003 using xenon with different dosages, durations and delays 
before treatment onset in our neonatal rat brain injury model and found that xenon approximately doubles the 
neuroprotective effect in combination with hypothermia, compared to hypothermia alone.[14, 28, 29] Since 2006 we 
have investigated xenon-hypothermia (XeHT) in our newborn piglet model of global hypoxia-ischemia.[8, 31] With this 
model we have extensively examined the effect of XeHT, Xe alone, HT alone as compared to no treatment. We have 
examined the effect on the brain and all organs, in particular the heart, liver, kidney and lungs. We have also examined 
the biochemical changes in the blood throughout the treatment period in all the treatment groups.  
 
In brief, we have not found any adverse effect of xenon in the piglet model – and we can document: 
- 
Improved neuroprotection compared to HT alone [15] 
- 
Better cardiovascular stability (reduced need for inotropic support) [31] 

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- 
No extubation delay [15] 
- 
No increase in oxygen requirements [15] 
 
Our large animal trial of XE-HT in piglets recently concluded with a very positive outcome supporting the result we 
found in rats, i.e. adding xenon to HT doubles the neuroprotection in both animal models. Also we found in both 
studies that HT and Xenon had additive effects with no interaction. 
 
A human neonatal feasibility study combining cooling (the established treatment) with xenon inhalation via mechanical 
ventilation was completed by this group 5/4/2011. This small scale safety study was a necessary requirement before a 
randomised clinical trial of cooling+xenon that would examine neurological outcomes could be conducted. The findings 
were similar to those listed above and have been documented and are given in more detail in Appendix 4. The design 
was such that the xenon duration increased from 18h and 3 patients received the maximal duration of 18h xenon which 
has been shown to be neuroprotective in the pig model. Increasing the duration had no adverse effect on the 
physiological parameters. 
 
2.0 
Objectives  
The aim of this study is to examine using primarily short term measures and secondarily long term outcomes, the 
potential neuroprotective effects of the cooling+xenon combination when compared to cooling alone. We will examine 
the feasibility of recruiting earlier than previous trials, <3h for HT and <5h for starting xenon and assess what 
proportion of the eligible infants we can recruit. We will compare the short term biomarkers (aEEG recovery, MRI score, 
LDH and time to full feeds) in the two groups with those obtained previously in our randomised dataset (infants from 
CoolCap and TOBY) as well as the large group cooled since 1/12/2006 under the same protocol.  In these groups of 
children we have both short term markers as well as Bayley outcome and have shown that our combined biomarkers 
has a PPV of 93%. 
 
Primary Objective:  
This is a randomised two group pilot study comparing;  
i) Adding xenon inhalation for 18 hours in combination with the (existing) whole body cooling to 33.5 °C for 3 days. 
ii) The established treatment of cooling the body down to 33.5 °C for 3 days.  
 
This will be applied in term newborn babies who are at moderate or high risk of brain injury following poor condition 
around the time of birth, the purpose being to reduce long term neurological impairment resulting from their 
condition. 
 
 
Our hypothesis is that early predictors of outcome* will show a trend towards an enhanced neuroprotective effect of 
the xenon-cooling combination over cooling alone. The early predictors will allow us to perform power calculations for 
a much larger neurological outcomes study of otherwise similar design. 
In addition we will examine the feasibility of earlier recruitment and start of xenon and whether we obtain the same 
early predictor data in the hypothermia-only group as we have in our previous hypothermia database. 
 (*the total clinical follow up period will be much longer than this as is already the case for cooled babies in Bristol) 
2.1 
Primary Endpoint 
 
This is a randomised two group pilot study comparing;  
1) xenon inhalation for 18 hours in combination with whole body cooling to 33.5 °C for 3 days, to  
2) the established treatment of cooling the body down to 33.5 °C for 3 days.  
 

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This will be applied in term newborn babies who display signs indicating moderate or severe brain injury following poor 
condition at birth. 
 
Our hypothesis is that we may observe an enhanced neuroprotective effect of the xenon-cooling combination over 
cooling alone assessed initially by early outcome predictors.  This will allow us to perform power calculations for a much 
larger neurological outcomes study of otherwise similar design. We have tested a combination of our early predictors  
(using our TOBY registry cooling data in 80 infants) against Bailey outcome at 18 months and found they have a positive 
predictive value of 94% in cooled infants  
 
Early predictors of outcome 
For the main analysis we will use 
Time to recovery after birth of a normal aEEG [1] 
MRI scan before 14 days of life [33, 2] 
Peak LDH value within 72h of life [4, 34] 
We will also collect data on: 
Plasma glucose at birth (in cord blood) 
Age in hours after birth when plasma lactate has fallen to 5mmol/L 
Different  inotropic  drugs  needed and the total duration in hours of any inotropic support 
Number of anticonvulsants given 
Amount and duration of sedation (e.g.morphine) 
Age at full oral feeds (breast or bottle or tube) 
Neonatal hearing screening result before 14 days of life 
Clinical examination at birth, at 7 days of age and at discharge including weight and head circumference 
 
Neurodevelopmental follow up is a part of the routine follow up of infants with HIE, Bayley examination at 18 months 
of age. 
Disability will be defined as any of: 
Bayley II mental developmental scale (MDI) score less than 70. 
Bayley II motor development scale (PDI) score less than 70. MDI and PDI will also be calculated as DQ, developmental 
score as this allows a larger range of score for those functioning at a low level [35]. Bilateral cortical visual impairments 
Hearing loss needing amplification > 40 DB. 
 
In addition any Adverse Events will be recorded and criteria have been devised for stopping the study early if necessary. 
This includes a Data Review Panel to review data when 4 xenon infants have undergone xenon treatment. 
 
2.2 
Secondary Endpoint 
A series of variables that are among the most relevant for evaluation of safety (see endpoints below) were examined 
closely in the previous 14 baby feasibility/safety study. We will continue to routinely monitor and record the same set 
of physiological variables in the proposed study, for a subset of data for a longer time period until after rewarming. 
 
• 
Endpoint 1 – defined as Mechanical ventilation and gas exchange parameters 
➢ 
The following variables will be measured before (from start cooling), during and after xenon 
administration (for 12h or until 12h after end of cooling  hours pending  which variable):Transcutaneous  
oxygen saturation, end-tidal carbon dioxide concentration, blood gas data, mechanical ventilation 
requirements (rate, peak inspiratory pressure, inspiratory time, PEEP settings),FiO2. Average 
percentage xenon in inspired gas mixture (when applicable). Tracheal tube cuff pressure. 
• 
Endpoint 2 – defined as Haemodynamic parameters 

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➢ 
The following variables will be measured before, during and after xenon administration: Systolic, mean 
and diastolic arterial pressures, Heart rate.  
 
• 
Endpoint 3 – defined as Inotropic drug requirements 
➢ 
These (drug, dose and duration) will be recorded before, during and after xenon administration until 
12h after end of cooling. 
 
• 
Endpoint 4 – defined as Marker of myocardial impairment/insult 
The following will be recorded before and after xenon administration: Plasma levels Troponin T (marker of myocardial cell 
death) recorded before and after xenon administration until 12h after end of cooling: 
• 
Endpoint 5 – defined as timecourse  and peak value of  Markers of hepatic impairment 
➢ 
These will be recorded before and after xenon administration until 12h after end of cooling: [Alanine 
aminotransferase , Alkaline phosphatase and  Lactate Dehydrogenase] 
• 
Endpoint 6 – defined as  timecourse and peak value of Markers of renal impairment 
➢ 
These will be recorded before, during and after xenon administration until 12h after end of cooling: 
oliguria is defined as [urine output < 1 ml/kg/h] from age > 24h, raised creatinine > 100 at > 24h of age. 
 
• 
Endpoint 7 – defined as Evidence of infection 
➢ 
These will be recorded: culture proven, need for antibiotics for 5 or more days, raised CRP occurring 
within 24h or later. 
 
• 
Endpoint 8 – defined as Length of hospital stay including duration of stay in local hospital after discharge from St 
Michaels hospital 
➢ 
This will be recorded 
 
• 
Endpoint 9 – defined as age when full oral feeding was achieved by breast or bottle or tube 
➢ 
This will be recorded 
 
• 
Endpoint 10 – defined as Haematology measurements 
➢ 
These will be recorded before and after xenon administration (these are routinely recorded 24 hrly): 
Coagulopathy [INR > 2 and/or APTT> 50]. Full blood count. 
 
• 
Endpoint 11 – defined as Serum chemistry measurements 
➢ 
These will be recorded before and after xenon administration: Serum sodium, potassium, chloride, 
magnesium, phosphate, calcium, (urea, creatinine as above), glucose, (liver enzymes as above), 
bilirubin, albumin. Drug levels may be analysed  on clinical indication  (Gentamicin levels, Phenobarbital 
levels).   
 
• 
Endpoint 12 – defined as aEEG background pattern and Evidence of seizures 
➢ 
These will be recorded before, during and after xenon administration until 12h after end of cooling: 
Evidence from continuous aEEG/EEG recording and any anticonvulsant treatments given. 
 
 
3.0 
Study Design 
This is a single centre prospective randomised clinical pilot study. 
 

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3.1  
 Study design and procedures 
 
Infants will be eligible for xenon if the St Michael’s hospital standard inclusion criteria for cooling are met and 
additional inclusion criteria for xenon administration are met. 
 
St Michael’s hospital standard inclusion criteria for cooling: 
Standard Hypothermia Treatment Criteria for 72 hrs of cooling  —  all of criteria A, B,  and C. 
A   Infants ≥ 36.0 weeks gestation (estimated or clinical assessment) with at least ONE of the following:  
  
1        
Apgar score of ≤5 at ten (10) minutes after birth  
2    
Continued need for resuscitation, including tracheal or mask ventilation, at ten minutes after birth  
 
 
3 
Acidosis defined as either umbilical cord pH or any arterial, venous or capillary pH within 60 minutes 
of birth less < 7.00 
 
4 
Base deficit ≥16 mmol/L in umbilical cord blood sample or any blood sample within 60 minutes of 
birth (arterial or venous blood). If the infant meets criterion A then assess for neurological abnormality using criterion B 
and C (by trained personnel): 
 
B 
Moderate or Severe encephalopathy as evidenced by any of the following --  
         
1 
Altered state of consciousness (reduced or absent responses or pathological irritability and hyper 
responsive and at least ONE or more of the following: 
 
2 
Hypotonia 
 
3 
Abnormal reflexes including oculomotor or pupillary abnormalities  
 
4 
Absent or weak suck  
 
5 
Clinical seizures, as recorded by trained personnel  
                                              And  
C 
At least 30 minutes duration of amplitude-integrated electroencephalography (aEEG) recording that shows 
abnormal background aEEG activity. The decision to cool is based on the worst 30 min section of the aEEG, not the best 
[35] or seizures (clinical or electrical) thus meeting ONE of the following:  
 
1 
Normal background with some (> 5 min)  electrical seizure activity  
 
2 
Moderately abnormal activity (upper margin of trace >10μV and lower margin <5μV) 
 
3 
Suppressed activity (upper margin of trace <10μV and lower margin of trace <5μV) 
 
4 
Definite seizure activity 
 
Exclusion criteria for cooling in the CoolXenon2 study 
1. 
Infants expected to be greater than 3 hours of age at the time of starting cooling treatment. 
2. 
Futility. Where prognosis is considered to be hopeless e.g. no cardiac output for 20 minutes. 
   
Additional inclusion criteria for xenon 
Before being considered for additional inhaled xenon therapy via the breathing gas mixture, the infant would need to 
meet further additional entry criteria (all must be met): 
1) 
Intubated, ventilated, sedated, being cooled. 
2) 
<5 hours old 
3) 
Any seizures under control. 
4) 
Weight > 2nd centile for gestational age 
5) 
Stable cardiovascular parameters; Mean arterial pressure >40mmHg. 
6) 
Oxygen requirement via mechanical ventilator < 40%. 
7) 
Positive End Expiratory Pressure (PEEP) requirement < 6cm H2O 
8) 
Arterial/capillary/venous pCO2  <7.0kPa (ideally arterial). Venous can be higher if peri-arrest and tissues 
have been very recently Ischaemic 
9) 
Postnatal age <5 hours 
10) 
Absence of major congenital abnormalities, imperforate anus and in particular any bowel obstruction, 
congenital abnormalities suggestive of chromosomal anomaly or other syndromes that include brain 
dysgenesis. Congenital syndromes affecting the brain should be excluded when diagnosed. 

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Consent  
Informed written consent will be obtained from a parent (only the mother can consent if parents are not married) after 
a full verbal and written explanation of the study by a named physician or trained nurse like an advanced nurse 
practitioner. Such staff will also meet with parents during the intervention period to ensure that they understand the 
study procedures and continue to consent to participate in the study. Information can be given by local trained staff 
and consent can also be taken over the phone with the mother if she is unable to be available for the consent process 
(e.g. cannot be moved shortly after Caesarean Section). 
Approval for the study is being obtained from the Regional South West Research Ethics Committee covering St 
Michael’s Hospital. 
Most of the patients will be born outside the study hospital (Outborn). Outborn patients are estimated to be >90% of 
patients. They are brought to the hospital by a dedicated retrieval team and ambulance from Bristol. 
The local delivery hospitals will have medical staff (e.g. consultants, specialist registrars, advanced nurse practitioners) 
trained in consenting for the CoolXenon2 trial. A training log with signatures, a short CV and competency approval will 
be kept centrally. 
Parents will receive a written information leaflet (1 page, short version) when the infant is eligible for cooling 
treatment. Staff will discuss CoolXenon2 with parents as soon as practically possible. Parents will be able to speak on 
the phone to a member of the treatment team if they need further information and help with the consent process. 
Parents will also be offered the opportunity to speak to members of the treatment team that are picking up the baby 
for transport. 
Trained staff on the transport team can take consent for the study. 
A more detailed information sheet regarding the trial will be given to parents after the first conversation or at the 
earliest suitable time. 
Which of the parents can consent to letting the child enter the trial? 
• 
Either parent if they are married. 
• 
If the parents are not married, only the mother can consent - provided she is awake and understanding (eg not 
under the influence of anaesthetic drugs)  
If the mother is not in a state to understand the situation  and the biological father does currently not have legal 
parental responsibility he can assent for the trial until the mother is awake/understanding the child’s condition and 
able to decide on consent.  
 
A parent who is eligible to consent can, at any time and without a specific reason, withdraw the child from the study. In 
this situation, xenon treatment will then be stopped as soon as possible and medically safe (within minutes). 
 
 
Randomisation  
The babies entered into the study will be randomised into two groups on a 1:1 basis. Randomisation will be via sealed 
opaque envelopes containing details of treatment allocation and [an] identifying adhesive label(s) to be attached to the 
CRF binder. Neonates meeting all the entry criteria can be included. In this study early randomisation before 5h of age 
is paramount. The maximum target delay before starting cooling is before 3h of age and for xenon this value is 5h of 
age. These are maximum delay values however so consent and randomisation need to take place as early as possible. 
 
Clinical management 
1)  
The neonates would be sedated, mechanically ventilated and cooled according to the protocol for cooling 
listed above, as this is standard treatment. In the case of retrieved babies, cooling is always started before 
transfer to Bristol (active or passive cooling). If not before, active cooling starts when the transport team 
arrives. Antibiotics, fluid management and sedative drugs used would be unmodified. 
2)  
Neonates would be entered into the study according to the set criteria within a maximum of 5hrs of birth with 
respect to adding xenon to the existing underlying standard cooling regime which has started within 3 hrs 
(passive or active). 

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Specific clinical management of cooling group 
1. 
This group will be cooled according to the normal protocols of the hospital as this is standard treatment.  
 
 
Specific clinical management of xenon+cooling group 
After initial resuscitation and attainment of a stable state, and inclusion in the study, the tracheal tube would be 
replaced with a cuffed commercially available tracheal tube (Kimberley-Clark microcuff) of the same or 0.5mm smaller 
size as the existing one and the cuff inflated until leakage of gas around the cuff had ceased audibly and according to 
the ventilator monitor. This particular tube has a high volume, low pressure cuff and is specifically designed for long 
term use on the paediatric or neonatal intensive care unit. The cuff pressure will be monitored and recorded at the 
time of initial inflation, during xenon administration every 2 hours and just prior to final deflation. If there are any post 
extubation adverse events such as stridor, or extubation fails secondary to vocal cord, nerve or subglottic damage, 
these will be recorded. The experience from our recent neonatal feasibility/safety study was that of the 14 babies, one 
baby developed post-extubation stridor requiring steroids.* See Appendix 4.  
*In  a recent very large study of cuffed tracheal tubes for anaesthesia in infants and neonates, the use of a cuffed tube did not 
increase risk of post-extubation stridor. In 2246 children, post-extubation stridor was noted in 4.4% of those with a cuffed tracheal 
tube and 4.7% of those with uncuffed tubes, with a much lower tube exchange rate in the cuffed tube group. See Appendix 11. 
 
1. 
The dose (fraction of xenon in breathing gas) planned for each patient in the xenon+cooling group will be 50%. 
It will be applied for 18 hours. It will be commenced as soon as is practicable but no later than 5h after birth 
once all the entry criteria / consent requirements have been met.  
 
2. 
If a baby is being retrieved from another local hospital to the study centre (Bristol) using the existing Bristol-
provided retrieval team and ambulance, AND they have been consented and randomised to receive xenon 
AND if it is deemed probable that the delay between birth and the start of xenon in Bristol would exceed an 
interval of 5 hours, then if logistically possible an assigned research team member will  accompany or meet the 
retrieval team and  commence xenon delivery at the local hospital or during the return transfer of the baby to 
Bristol. 
3) 
Full data sets will be acquired in two groups of 16 patients. The mortality rate in the patients referred for 
cooling to Bristol is ~25%.  
 
4) 
Cooling will be for 72 hours using the clinically chosen cooling device in both groups, as is current standard 
practice for cooling. 
 
Further information on the oxygen fraction in the breathing gas mixture 
The Xenon we intend to use (LenoXe) is currently licensed for anaesthesia in adults. The LenoXe SmPC specifies that 
xenon should be administered (for adult anaesthesia) with at least 30% oxygen in the breathing gas mixture.  
It is our intention in this study to administer an oxygen fraction in the breathing gas to ensure adequate oxygenation of 
the blood of the neonate, but not to give an excess, as there is also a real risk of hyperoxic brain damage in this group 
of neonates if the oxygen fraction is too high. Consequently, in a neonate with normal lungs being sedated and 
ventilated for cooling rather than for any lung problems, the inspired oxygen fraction could equal that of air i.e. 21%. 
No neonate would ever receive less than 21% oxygen and the fraction delivered would be specific to each individual 
according to clinical need. 
 
Explanation: 
The reason the LenoXe SmPc specifies 30% oxygen is following the normal practice of anaesthesia using other gases and 
vapours, because during anaesthesia in adults the ventilation/perfusion mismatch in the lungs becomes very slightly 
less efficient than in the awake state. This is due to changes in muscle tone, diaphragm position/shape and effects of 

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gravity on distribution of blood flow through regions of the lung. This is why although humans are designed to breathe 
air (21% oxygen), under anaesthesia in someone with normal lungs we would traditionally use approximately 30% 
oxygen (more if there were any lung problems as clinically indicated). 
 
It should be noted that this anaesthetic tradition to use a slightly higher inspired oxygen fraction than might strictly be 
required developed before it became commonplace and later mandatory to use pulse oximetry to continuously 
monitor oxygen saturation of the blood and end-expired carbon dioxide monitoring to continuously monitor the 
adequacy of ventilation (in terms of carbon dioxide removal from the blood) which became widespread in the late 
1980’s / early 1990’s. 
 
In the neonates of this study the situation is different as they have all recently suffered a hypoxic-ischaemic (HI) insult 
to the brain and other organs around birth. Ventilating them with a gas mixture containing an oxygen fraction even 
slightly higher than necessary is considered highly undesirable as in this situation it can actually worsen the subsequent 
brain injury. This explains recent changes to resuscitation equipment for the newborn where the 100% oxygen supplies 
have been replaced with air/oxygen blenders.  The new ILCOR Resuscitation Guidelines [37] state that term newborns 
should first be resuscitated in air, then with a higher concentration of oxygen if pulse oximetry or clinical signs suggest 
poor oxygenation. 
 
i) It is worth noting that regional variations in ventilation/perfusion throughout the regions of a healthy neonatal lung 
are less affected by anaesthesia/sedation than in a (much larger) adult so the physiological (anaesthetic) justification 
for automatically using 30% oxygen is weaker in the neonate. 
However the more relevant points with respect to this study are: 
ii) While in anaesthesia practice it may be normal and quite harmless to set an inspired oxygen fraction slightly higher 
than strictly necessary, in neonates that have suffered a hypoxic-ischaemic insult to the brain and other organs around 
birth, it is considered highly undesirable to administer an inspired oxygen fraction that is any higher than the amount 
required for adequate oxygen delivery to the organs.  We have recently shown experimentally that 30 min of 100% 
oxygen after hypoxia-ischaemia increased injury [38]. 
iii) Consequently,  
- 
we monitor oxygen saturation of the blood of the neonate using continuous pulse oximetry (with audible and 
visual alarms),  
- 
we continuously monitor adequacy of ventilation with a neonatal end-expired carbon dioxide monitor which 
reflects the systemic arterial carbon dioxide content. While mandatory in adult intensive care practice this is 
not yet the case in neonatal practice due to unavailability of suitable monitors for neonates, a situation which 
is now changing. 
- 
We also routinely monitor oxygen saturation of the blood periodically in ventilated neonates by analysing 
arterial blood samples using a blood gas analyser. In neonates that have experienced an HI insult around birth 
the attending physicians are not only checking that the oxygen content is not too low but also they are 
checking it is not too high. A slight elevation that would normally be acceptable is not acceptable in this 
particular group of babies and if too high they will actively request that the inspired oxygen fraction in the 
breathing gas be reduced. 
- 
As a result of the above, the inspired breathing gas might contain a theoretical maximum oxygen fraction of 
40% as stated in the protocol if clinically required due to lung problems , but also this may for the above 
reasons be deliberately set as low as 21% (as in room air) if the lungs are normal. 
The desired inspired xenon fraction is to be set at 50% as per the protocol. The “balance gas” in situations where a 
moderate oxygen fraction is being used will be nitrogen. This will simply be room air which although containing 21% 
oxygen is otherwise mainly composed of nitrogen. 
 
Vigilance and monitoring 
This would be ongoing during every case. It would include 
- 
Blood gases 2 hourly or as clinically requested up to 1 hourly. 
- 
(cardiac echo /doppler) where available 
- 
Blood Pressure 

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- 
Heart rate 
- 
Oxygen saturation by pulse oximeter SaO2 
- 
Xe concentration and O2 concentration in gas mixture 
- 
End Tidal CO2 (ETCO2) (Respironics mainstream monitor with very low deadspace in neonatal connection) 
 
Action to be taken with respect to typical problems in this patient group 
1) 
Hypotension or inadequate cardiac output: 10ml/kg 0.9% Saline (or occasionally 4% human albumin or blood) 
as required (x2). 
Dopamine infusion commenced (up to 20mcg/kg/hr) followed by Dobutamine (up to 20mcg/kg/hr), then 
Hydrocortisone up to 2.5mg/kg 6 hourly or other inotrope as indicated.  
If not effective then Xe delivery is stopped and conventional ventilation/gas mixture resumed. 
2) 
Low SaO2 or low oxygen partial pressure on blood gas analysis: 
Increased oxygen fraction in breathing gas mixture as required up to maximum of 40%. 
If not effective, then Xe delivery stopped and conventional ventilation/gas mixture resumed. If reason for high FiO2 is 
easily solved, e.g. improved by surfactant delivery or changed ventilation settings or clearing a blocked tube, then 
xenon  can be resumed. 
3) 
High End-Tidal CO2 or CO2 partial pressure on blood gas analysis: 
Increase peak pressure and/or breathing rate settings on mechanical ventilator. 
If not effective then Xe delivery stopped and conventional ventilation/gas mixture resumed. This is readily achieved by 
disconnecting the ventilator hoses from their point of attachment to the xenon breathing system and connecting them 
directly to the tracheal tube of the neonate. 
 
 
At the end of the prescribed period of Xe delivery the tracheal tube would be reconnected directly to the mechanical 
ventilator and normal ventilation and gas mixtures set as clinically appropriate. The cuff of the tracheal tube would be 
deflated. This tracheal tube would be replaced with an uncuffed tube at a later timepoint as clinically indicated or kept 
until the patient was extubated after rewarming. Cooling regimes last for 72hrs before slow rewarming commences 
(0.1-0.4°C per hour). The standard cooling protocol would continue for many more hours after cessation of the 
additional xenon regime. 
 
 
Risks/benefits and risk minimisation 
Potential risks from xenon: 
The known effects of xenon in humans have all been derived from adult anaesthesia studies. Xenon is known to have 
minimal effects on the strength of the heart contractions or the blood pressure.[37-40] A slight slowing of pulse rate 
has been seen in some studies - often not statistically significant. 
Xenon is analgesic and causes sedation. These might be considered useful properties in a sedated baby on an Intensive 
Care Unit. 
Xenon is a dense gas. Erring on the side of caution we would not use it in this early study in any baby with airway 
narrowing or similar lung problems, the exclusion criteria reflect this. Note that the use in piglets weighing 1.5 kg and 
small airways did not display any ventilation/airway problems (Appendix 4). As with other anaesthetic gases it can 
diffuse into gas filled cavities in the body such as the bowel. This happens only slowly in adults, and more slowly than 
with other anaesthetic gases such as nitrous oxide, however for this reason it would not be used in any situation where 
the bowel was obstructed (our xenon inclusion criteria reflect this). 
 
In animal neonatal studies, there have been no side effects and we can document: 
- 
Improved neuroprotection [15] 
- 
Better cardiovascular stability [31] 
- 
No extubation delay (delay coming off the mechanical ventilator) [15] 
- 
No increase in oxygen requirements [15] 

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From studies using xenon as an anaesthetic in adults, of which there are many, the experience is that xenon has 
remarkably few side effects and in particular produces minimal haemodynamic disturbance compared to conventional 
anaesthetics. [37-40] 
Because xenon is almost chemically inert, it is eliminated from the body completely unchanged – it is eliminated from 
body tissues via the circulation and lungs at the end of the procedure. Xenon, although uncommonly used due to its 
high cost, does therefore have a license for use as an anaesthetic in adults in several countries, including the UK. 
 
In 2010/2011 our group undertook and successfully completed the first human neonatal feasibility/safety study of 
xenon+cooling, mainly 50% xenon for periods of up to 18hrs. From this study, in terms of safety, we can document: 
• 
It is feasible to give 50% xenon for up to 18h in infants undergoing therapeutic hypothermia [9] 
• 
Only 0.2-0.3L/hour xenon was used with a closed loop xenon breathing system 
• 
A cuffed tube did not adversely affect ease of extubation 
• 
Xenon is sedative and other sedation is needed when xenon is discontinued 
• 
No significant cardiovascular or respiratory changes before, during and after xenon 
• 
In one child with abnormal/immature lungs, xenon did not increase FiO2 requirement. 
 
See Appendix 4 
 
From the perspective of babies who may already be unwell, the main points to note therefore are: 
i) 
Xenon is not broken down to any “by products” by the metabolism of the body as many other drugs are, as it is 
an almost chemically “inert” elemental gas. 
ii) 
Xenon is very free of side-effects in the adult experience, which may be due to this “inert” nature, but perhaps 
most importantly: 
iii) 
Xenon is eliminated from the body completely unchanged via the lungs within a few breaths. This means that if 
there is any problem, unlike the situation with any drug injected into a vein, xenon is a reversible treatment, 
i.e. it can be easily removed completely, rapidly and unchanged from the body at any time. This ability to 
reverse application of xenon and rapidly eliminate it unchanged from the patient in the event of any problem is, 
although unusual, a key factor from the perspective of safety. 
 
 
When the xenon is being administered, a special breathing circuit will be connected to the ventilator designed for this 
purpose. It will be operated by a member of the team who has documented experience running and troubleshooting 
with this equipment. (see section 4.0). 
 
 
 
 
Potential risks from breathing system: 
We are using a new breathing circuit to deliver this gas. This has been developed over many years by a Consultant 
Anaesthetist who is a co-researcher on this team and world leader on this subject. It has been tested extensively in 
laboratory neonatal pig simulations of the condition (see section 4.3.1). To minimise risk of any technical problems: 
 
i) 
The equipment design is being evaluated for safety by the MHRA. It will be professionally constructed from all 
medical grade materials. 
ii) 
The design is such that the xenon system is placed between the standard mechanical ventilator and the baby. 
This means that if there is any technical problem, the ventilator can be immediately connected directly to the 
baby and the xenon system removed in one simple intuitive operation. 
iii) 
The gas composition, in particular oxygen, of the circuit gas will be continuously measured, as will xenon and 
the end-tidal carbon dioxide (which reflects the arterial value). 
iv) 
The breathing system has an overpressure release valve in the event of any mishap. 

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v) 
Furthermore if there were any problem due to the xenon gas itself, reconnection directly to the ventilator 
would also allow all the xenon to be breathed out from the baby within a few breaths, i.e. the xenon 
treatment is rapidly reversible. Finally: 
vi) 
The xenon will be delivered by trained personnel who have also been involved with laboratory trials using 
xenon in animal models  
vii) 
The possibility of interaction between the xenon gas and the materials of the breathing circuit has 
 
been considered. As xenon is chemically “inert” i.e. does not form chemical compounds except in the 
 
most extreme circumstances, there is no perceived risk. 
viii) 
A full risk assessment in accordance with standard medical device regulatory requirements has been 
undertaken and thoroughly documented 
 
This design of breathing system has now been evaluated in this same patient population as in our recently completed 
14 baby human feasibility/safety study. The findings are summarised in Appendix 4. 
 
Use of cuffed tracheal tube: 
After onset of cooling and attainment of a stable state, the tracheal tube would be replaced with a cuffed commercially 
available tracheal tube (Kimberley-Clark microcuff) of the same or 0.5mm smaller size as the existing one.  
To minimise the gas pressure in the cuff:  
i) The cuff would be inflated until leakage of gas around the cuff had just ceased audibly and also according to the 
ventilator monitor.  
ii) This particular tube has a high volume, low pressure cuff and is specifically designed for long term use on the 
paediatric or neonatal intensive care unit. Publication of a large scale randomised multicentre trial of uncuffed versus 
modern cuffed tracheal tubes in small children (0-5yrs, n=2246) has recently taken place. The incidence of 
complications was no greater than that seen with uncuffed tubes. The conclusions were “The use of cuffed TTs in small 
children provides a reliably sealed airway at cuff pressures of <or=20 cm H2O, reduces the need for TT exchanges, and 
does not increase the risk for post-extubation stridor compared with uncuffed TTs.” [41] (See Appendix 11 for abstract 
of this paper). 
iii) The cuff pressure will be monitored and recorded at the time of initial inflation, during xenon administration every 2 
hours and just prior to final deflation.  
N.B. Any Adverse Events such as stridor or failure of extubation secondary to vocal cord, nerve or subglottic damage 
will be recorded. 
In this way any theoretical risk of post-extubation stridor will be minimised. Any such Adverse Events at or around the 
time of extubation will also be recorded. 
 
Experience with this cuffed tube in neonates with xenon:  
In 2010/2011 our group successfully undertook and completed the first human neonatal feasibility/safety study of 
xenon+cooling, mainly 50% xenon for periods of up to 18hrs. From this study, in terms of safety of the cuffed tube we 
can document: 
- 
Babies were reintubated with a cuffed tube 0.5mm smaller than the uncuffed tube that had been in place 
previously. Cuff pressure was measured frequently during the period of xenon delivery and the cuff was 
deflated post-xenon delivery. 
- 
The target cuff pressure was the lowest cuff pressure we could achieve without there being any gas 
leakage past the cuff. This was typically 11cm H2O, - much lower than the maximum of 20 cm H2O used in 
the above randomised tracheal tube study 
- 
We observed stridor post-extubation in 1 of the 14 babies. See Appendix 11. 
 
Further information can be found in Appendix 4. 
 
Cleaning/disinfection: 
The entire circuit will be single-use. Between patients, the entire breathing circuit and hoses will be replaced with a 
fresh item.  
 

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Potential benefit to research participants 
The hypothesis is that babies enrolled into the study may derive additional neurological benefit from the xenon/cooling 
combination exceeding that seen from cooling alone, following the pattern seen in all the in-vivo small and large animal 
studies performed so far. 
  
3.2 
Follow Up 
 
Short term information and investigations (before discharge from hospital): 
These are part of routine clinical practice. 
 
1. 
Survival 
2.  
Duration of hospitalisation 
3. 
Time to full oral feeds, breast or bottle 
4. 
Hypoxic-ischaemic or other injury on MRI scan (standard sequences for this injury) preferably aged 7-12 days 
of age and Magnetic Resonance Spectroscopy as a part of the MRI examination if available 
5.  
Intracranial or intraventricular haemorrhage (on MRI, CT or ultrasound) 
6.  
Major venous thrombosis (on MRI or ultrasound) 
7. 
Resistance Index (Doppler examination of cerebral blood flow velocities) 
8. 
Amplitude integrated EEG (aEEG) continuously recorded until after rewarming. Assessment of time to 
normalisation of background activity, seizure occurrence and duration 
9.  
Pulmonary hypertension needing treatment 
10.  
Pulmonary haemorrhage  
11.  
Pneumonia 
12.  
Pulmonary air leak 
13.  
Systemic hypotension needing inotropic support 
14.  
Prolonged blood coagulation time assessed before xenon and at ~24 hours and/or at clinically indicated   
timepoints 
15.  
Cardiac arrhythmia (not temperature induced low Heart Rate) 
16.  
Thrombocytopenia (platelets <100,000/ul) 
17.  
Culture proven sepsis 
18.  
Necrotising enterocolitis, medical, radiological or surgically proven  
19. 
Plasma markers of global (increased lactate dehydrogenase (LDH)) or cardiac compromise (increased cardiac 
Troponin T (cTnT)) 
20.  
Renal failure treated with dialysis 
 
 Short term assessment neurological evaluation will include: 
1) Time to recovery after birth of a normal aEEG [1] 
2) MRI scan before 14 days of life [33, 2, 44]  
3) Peak LDH value within 72h of life [4, 34]  
 
We will also collect data on: 
4) First plasma glucose after birth (usually from cord blood) 
5) Age in hours after birth  when plasma lactate has declined to <5mmol/l 
6) Number and type of inotropic drugs needed during stay on the neonatal intensive care unit (typically the period 
from birth to 3-5 days of age) and the total duration in hours of any inotropic support 
7) Number of anticonvulsant drugs given during stay on the neonatal intensive care unit. 
8) Amount and duration of sedation (eg morphine) while ventilated mechanically on the neonatal intensive care unit. 
9) Age at full oral feeds (breast or bottle or tube) 
10) Outcomes of neonatal hearing screening before 14 days of life 
11) Clinical examination at birth, at 7 days of age and at discharge including weight and head circumference 
Long term follow up (at 18 months) 

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Neurodevelopmental follow up is a part of the routine follow up of infants with Neonatal Encephalopathy.  Bayley II 
examination at 18 months of age is used to compare the results from this study with our large local patient database 
and previous randomised controlled trials (CoolCap, Gluckman 2005; TOBY, Azzopardi 2009) [10, 11] where Bayley II 
was also used: we were a main recruiting centre for these trials. 
 
Disability will be defined as any of: 
Bayley II mental developmental scale score (MDI) less than 70. 
Bayley II motor development scale score (PDI) less than 70.  MDI and PDI will also be calculated as developmental 
quotients (DQ),  as this allows a larger range of score for those functioning at a low level [35].                                Bilateral 
cortical visual impairments.  
Hearing loss needing amplification > 40 DB. 
 
Additionally: 
We will do both short-term (14 days) and long-term (18 months survival) follow-up.  In cooled babies we have shown 
that short-term predictors such as MRI at day 8 [2], time to normal aEEG [1] and peak LDH before 72h [4] predict long-
term outcome with a positive predictive value of 84%, 92% and 80% respectively.  In this study we will be able to 
examine these predictors for cooled babies receiving xenon treatment.  By defining this relationship one can calculate 
the sample size for a large trial using short-term outcome. 
 
3.3 
Justification of Design 
A human neonatal randomised pilot study comparing cooling (the established treatment) with the cooling+50% xenon 
combination is now the next logical step (see “Justification of Treatment” 3.4 below). This study is necessary for 3 
reasons:  
1) To validate our ability to recruit a large proportion of infants needing cooling as early as 3h of age and start 
xenon by 5hrs. 
2) To examine the positive predictive value of our early outcome biomarkers proposed from the previous 100 
cooled babies and compare with these.  
3) Use these data for the statistical power calculations to estimate the group sizes for a larger randomised clinical 
trial of cooling+xenon.  This approach follows a similar pattern to the early studies of cooling in neonates; a 
human technical feasibility/safety study [42] was performed using different target temperatures, followed by a 
study using a fixed temperature protocol for 72hours [20]. This protocol was then used in CoolCap [10], 
modified slightly for NICHD (National Institute of Child Health and Human Development)[43]  and again used in 
TOBY, which were the 3 first large randomised controlled cooling trials. [12] 
 
Group size calculation  
Sixteen babies will be recruited into each group (cooling+xenon vs cooling alone) at random. The cooling will be applied 
as standard treatment if cooling criteria are met. Addition of xenon in combination with this underlying cooling will take 
place in the group randomised to receive cooling + xenon. 
For pilot studies of this type the recommendation is a sample size of 12 per group. The justifications for this sample size 
are based on  
i) 
Feasibility – allows convenient block sizes, for example our intention for a data review committee to 
review data sets at block intervals of 4 neonates. 
ii) 
Precision about the mean – little additional precision to be gained by having a larger group size than 12 
[44]. 
iii) 
Precision about the variance – little additional precision to be gained by having a larger group size than 12 
[44]. 
Reference [44] presented in full in Appendix 10. 
 
The first 15 neonates were recruited in a period where the xenon ambulance transfer system was not ready for use. 
The clinical staff employed to recruit and deliver the xenon in the ambulance needed time to gain experience using the 
system before using it independently away from the base hospital without the supervision of Dr John Dingley. This has 
led to a similar number of babies which we failed to recruit (due to the time limitation) as the number recruited to 

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xenon. We therefore wish to recruit a further 8 babies to assess the feasibility to recruit, more reliably, consecutive 
babies fulfilling the entry criteria within the confines of the protocol 
 
 
3.4 
Justification of Treatment / Procedure 
Even with the best available treatment (hypothermia) infants with HIE have a considerable risk of death or disability of 
51%. This study offers an additional treatment which has been shown in two animal species to improve (double) brain 
protection over and above the protection from cooling alone. Our large animal trial of Xenon-hypothermia in piglets 
conducted with a delivery system of the same design as proposed for this study has very recently concluded with a very 
positive outcome [15] supporting the result we found in rats, ie adding xenon to HT doubles the neuroprotection [14, 
17].  
 
This equipment has recently been used in 14 human neonates during our recently completed human feasibility/safety 
study (Appendix 4). 
 
4.0 
Study Therapies 
4.1 
Test Article: Description 
Overview 
The neonatal xenon breathing device (NXBD) is a gas delivery circuit with some similarities to an anaesthesia circuit that 
is temporarily placed between a standard mechanical ventilator and the tracheal tube of a neonate to deliver xenon as 
a therapy in the breathing gas. It is designed for use in neonates who already require mechanical ventilation in this 
manner on a neonatal intensive care unit. Its purpose is to provide a gas mixture to the lungs that contains not only an 
appropriate oxygen concentration to maintain life, but also to provide a concentration of up to 50% xenon in this 
mixture. The reason for this is that xenon shows great promise as a neuroprotectant and has been shown to reduce 
neurological damage in both small and large laboratory in-vivo models of neonatal hypoxia-ischaemia (birth asphyxia 
for example). By re-circulating the exhaled gases after removal of carbon dioxide then, as the uptake of xenon by a 
neonate is very low and the system does not “vent” any exhaled gas to the environment, it provides a very economical 
method of xenon delivery. Such economy will be essential for any future clinical use of xenon as this gas is both limited 
in availability and extremely expensive at approximately £20/litre. While the (minimal) xenon uptake is replaced 
manually by the operator, the breathing device automatically adds oxygen as required to match metabolic uptake by 
the patient. This is not achieved by complex sensors and electronics but by a straightforward mechanical mechanism 
for reliability. Furthermore, if xenon replacement is stopped, the inspired oxygen concentration will tend to very slowly 
increase i.e. it will not fall as the patient consumes oxygen from the circuit – these are both inherent safety features. 
The most important and intuitive safety feature is that in the event of any problem, the mechanical ventilator patient 
connector can be disconnected from the breathing system and reconnected directly to the tracheal tube of the 
neonate, instantly restoring normal ventilation and also allowing any xenon to very rapidly dissipate from the tissues of 
the neonate. 
4.2 
Test Article: Principles of Operation 
If no fresh oxygen is supplied to a conventional anaesthesia circle system the patient will consume all oxygen present 
until a hypoxic mixture develops. Therefore in a closed circle system, fresh gases must be added at a rate exactly 
matching patient uptake of each gas. There are various ways to achieve this. In the simplest of closed underwater 
diving systems, the user will breathe pure oxygen around a circuit similar to an anaesthesia circle. In time, by metabolic 
oxygen consumption, the reservoir bag will completely collapse part-way through an inspired breath. At this point, by 
continued inspiratory effort, a demand valve on an attached oxygen cylinder will open, providing the missing volume of 
oxygen to complete the inspiration phase. If we now imagine this circle to contain a mixture of xenon (slow patient 
uptake) and oxygen (metabolic uptake) a different situation develops. It can be envisaged that substitution of these two 
uptake volumes with pure oxygen at each end-inspiration would produce a slowly increasing inspired oxygen fraction 
(FiO2). 
We have incorporated these concepts into a ventilator driven closed circuit where a standard Neonatal Intensive Care 
Unit (NICU) ventilator, set to deliver 100% oxygen in each breath to the circuit, provides not only the motive power but 
also, via a special volume substitution valve, the required oxygen replenishment in place of the demand valve in the 
diving example. 

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When delivering a xenon/oxygen mixture there would then be a background tendency for the FiO2 to slowly increase 
while the inspired xenon concentration decreases at a similar rate. This provides a degree of hypoxic mixture protection 
without use of oxygen sensor and computer software controlled electronic valves. In other words, adequate oxygen 
supply, the most critical function of any breathing system, is not entirely dependent on correct functioning of sensors, 
software and electronic dosing valves, as would be the case with an electronically controlled system. 
Against this inherent safety feature of a very slowly increasing the FiO2, and the minimal xenon uptake of a neonate 
from the closed loop circle breathing system, xenon can then be delivered to the circle in small volumes under manual 
control to offset this trend, replacing the minimal patient xenon uptake. 
The design of a breathing circuit to achieve these design aims is described in Figure 1.  
 
Figure 1a. Diagram of the breathing system 
 

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Figure 1b. Views of breathing system (without hoses) 
 
The xenon delivery system is designed to be fitted between a conventional neonatal intensive care unit (NICU) 
mechanical ventilator (SLE 2000, SLE, South Croydon, UK) and the tracheal tube. The latex-free bag in the lower 
chamber has a volume of 500ml, larger than a neonatal tidal volume, providing free space to accommodate added 
xenon bolus volumes without overspill. The removable soda-lime canister has a volume of 510ml permitting long 
periods of ventilation without replacement. 
In this design, a small aliquot of oxygen enters the closed circle upper part of the circuit at each end-inspiration from a 
lower bag-in-bottle chamber (where it is present as the driving gas from the ventilator) via a dedicated oxygen 
substitution valve. Modern NICU ventilators maintain a bias gas flow throughout the breathing cycle. At end-expiration 
this displaces any residual CO2 from the “Y” connector reducing CO2 rebreathing. However with a closed circuit, the 
absence of a bias flow combined with small neonatal tidal volumes means that an efficient self-closing, leak free, low 
opening pressure inspiratory valve was required to prevent rebreathing. A unidirectional valve performs this function. A 
similar valve design is used as the expiratory valve and as the oxygen substitution valve.  
Gas delivery to breathing system:  
Oxygen consumed by the neonate from the circle is replaced automatically via the oxygen substitution valve as 
described above and in Figure 1. The slow-rising FiO2 tendency (a condition of inherent safety against the development 
of accidental hypoxic mixtures) is then deliberately offset by occasional manual delivery of xenon boluses to the circle, 
so maintaining the target xenon concentration – the combination of closed circuit, low patient weight and low xenon 
uptake making these xenon doses very infrequent (<200ml Xe per hour from laboratory data). 
 

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Figure 1c. Details of exact medical components used to construct the hoses of the breathing circuit, with part 
numbers. Hoses, humidification chamber and connectors all manufactured by Armstrong Medical Ltd, UK 
 
 

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We have previously delivered xenon using high pressure xenon cylinders with electronic valves actuated by both 
computer and manual control. After using servo control in the past we realised that due to the slow uptake of xenon, 
manual addition of xenon boluses would not be particularly onerous facilitating this more straightforward design 
devoid of any computer control systems. 
The manual xenon dosing mechanism is designed to function at ambient pressure for additional simplicity and safety, 
so eliminating any risk of the circle “flooding” with xenon due to a cylinder/regulator/electronic malfunction (Figure 2). 
 
Figure 2. 
 
A flexible bulb and valve arrangement allows manual addition of ~50ml xenon boluses to the circle breathing system, 
from a previously filled reservoir bag of xenon at ambient pressure. These are added to the expiratory limb of the 
circuit to allow maximum mixing with existing gases in the circle before entering the lungs. The small flexible bulb 
volume of 50ml was selected because the small bulb volume combined with its slow refill properties further aids even 
gas mixing, it being impossible to rapidly add a large xenon bolus. Erring on the side of caution, our circuit was primed 
with oxygen. The xenon/oxygen monitors are constantly observed as in the conduct of a conventional anaesthetic. 
Deviations in xenon concentration of more than 2-4% from target are corrected by the operator adding xenon to the 
circuit, each 50ml bolus typically producing a 2% increase in xenon concentration. These corrections offset the inherent 
tendency of this circuit design to generate a very slowly increasing oxygen concentration (O2 + minimal Xe 
consumptions being replaced with equal volume of oxygen via substitution valve). 
The overall design aims were that this breathing system should (i) be driven by a standard NICU ventilator, (ii) have 
inherent hypoxic mixture prevention properties not dependent on electronics (iii) provide the user with the most 
intuitive treatment reversal method; reconnection of the neonate directly to the NICU ventilator. It performs all these 
functions. 
  
4.3 
Test Article: Clinical Development 
The research paper (Reference 15) is a technical evaluation of the xenon delivery system and the use of inhaled xenon in 
an in-vivo laboratory model that replicated the human clinical scenario of; global hypoxic ischemic insult in a neonate 
followed by cooling (the standard treatment) and concurrent xenon administration. It describes the early clinical 
development and performance of the delivery system and is attached in full as Appendix A2. 

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Appendix 5 summarises the data obtained when this breathing system design was used in our recent 14 baby human 
neonatal feasibility/safety study. 
 
4.3.1 
Proof-of-Concept Pre-clinical Studies 
Following the technical feasibility study [15] above, physiological data has been obtained by the research group in a 
much larger laboratory experiment over 5 years in neonatal piglets who were subjected to a previously described global 
hypoxic-ischemic insult, resuscitated, and then randomised to receive varying combinations and durations of cooling 
and xenon. The xenon delivery system used for this large pre-clinical study was the same as the one proposed for the 
clinical feasibility study. 
 
This pre-clinical study has also been is published as a paper: 
Xenon enhances hypothermic neuroprotection in asphyxiated newborn pigs. Chakkarapani E, Dingley J, Liu X, 
Hoque N, Aquilina K, Porter H, Thoresen M. Ann Neurol. 2010 Sep;68(3):330-41.[15] 
 
 
Additional details on the conduct of this laboratory pre-clinical study are given in Appendix 5 and a large quantity of 
physiological data is also supplied in this appendix demonstrating the physiological effects of cooling alone and then 
combinations of xenon + cooling in neonatal pigs after this severe global hypoxic-ischaemic insult. 
 
 
 
4.3.2 
Proof-of-Concept Clinical study 
In March 2011 this research group successfully completed a clinical feasibility/safety study of inhaled xenon in 
combination with cooling using this equipment design to deliver xenon in 14 human neonates.  
A large quantity of physiological data was acquired and this is presented in Appendix 5. 
 
4.4 
Test Article: Regulatory Status 
The Neonatal Xenon Breathing Device is not CE marked in Europe and will therefore any UK clinical study involving its 
use will require review by, and approval from, the UK Competent Authority, the Medicines and Healthcare products 
Regulatory Agency (MHRA). Ethical approval for the study will be obtained from the appropriate Research Ethics 
Committee (REC) prior to commencement. 
4.5 
Test Article: Packaging and Labelling 
The Neonatal Xenon Breathing Device requires no packaging and will be clearly labelled in compliance with the 
requirements of the EU Medical Devices Directive. Devices used in any clinical trial will clearly be marked “Exclusively 
For Clinical Investigations”. 
 
4.6 
Test Article: Component Tracking 
Use of the Neonatal Xenon Breathing Device will be tracked and reconciled throughout and upon completion of the 
study. Any complications with the device or components of the device should be managed by contacting the study 
Sponsor via the following telephone numbers: 
• Mary Perkins, R and D Department Level 3,  Education Centre, Bristol BS2 8AE. Tel 0117 3420233  (office hours) 
• Dr John Dingley Mobile: 07735 379471  (all other times) 
4.7 
Control/Comparator Therapy 
This is a randomised comparative pilot study. The control group will receive the standard treatment for this condition 
which is whole body cooling for 72 h as it would be unethical to withhold the normal treatment from the control group. 
The treatment group (experimental group) will also receive an identical cooling regime but in addition will receive 50% 
xenon within 5h of age in the breathing gas mixture via the NXBD breathing circuit for a period of 18h. 
5.0 
Patient Selection 
Potential study participants will be identified via the existing identification system used at St Michaels for 
administration of their (standard) cooling regime for the region. 

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There is good evidence that the earlier cooling (now standard treatment) is started, the greater the ultimate benefit. 
Consequently neonates are often allowed to passively cool during retrieval to Bristol, where active cooling is then 
continued, in a bid to start the process as early as possible. This argument is also likely to be true for xenon and there is 
in-vivo laboratory data to support this. Parents of potential participants in study therefore need to be approached as 
early as possible after birth if their baby meets entry criteria for the study. 
 
Therefore they will first be approached by a trained medical member of the clinical team. This person will briefly  
explain the study to the parents of the neonate with the aid of the information sheet, and later a  member of the team 
will obtain written consent where this has been agreed.  
 
Informed written consent will be obtained from a parent (only the mother can consent if parents are not married) after 
a full verbal and written explanation of the study by a named physician or trained nurse such as an advanced nurse 
practitioner. Such staff will also meet with parents during the intervention period to ensure that they understand the 
study procedures and continue to consent to participate in the study. Information can be given by local trained staff 
and consent can also be taken over the phone with the mother if she is unable to be available for the consent process 
(e.g. cannot be moved shortly after Caesarean Section). 
Approval for the study is being obtained from the Regional South West Research Ethics Committee covering St 
Michael’s Hospital. 
Most of the patients will be born outside the study hospital (Outborn). Outborn patients are estimated to be >90% of 
patients. They are brought to the hospital by a dedicated retrieval team and ambulance from Bristol. 
The local delivery hospitals will have medical staff (e.g. consultants, specialist registrars, advanced nurse practitioners) 
trained in consenting for the CoolXenon2 trial. A training log with signatures, a short CV and competency approval will 
be kept centrally. 
Parents will receive a written information leaflet (1 page, short version) when the infant is eligible for cooling 
treatment. Staff will discuss CoolXenon2 with parents as soon as practically possible. Parents will be able to speak on 
the phone to a member of the treatment team if they need further information and help with the consent process. 
Parents will also be offered the opportunity to speak to members of the treatment team that are picking up the baby 
for transport. 
Trained staff on the transport team can take consent for the study. 
A more detailed information sheet regarding the trial will be given to parents after the first conversation or at the 
earliest suitable time. 
Which of the parents can consent to letting the child enter the trial? 
• 
Either parent if they are married 
• 
If the parents are not married, only the mother can consent - provided she is awake and understanding (eg not 
under the influence of anaesthetic drugs)  
• 
If the mother is not in a state to understand the situation (and the parents are living together but are not 
married) the father can consent on behalf of the mother.  The consent process must be repeated with the 
mother as soon as she is able to understand the child’s condition. 
A parent who is eligible to consent can, at any time and without a specific reason, withdraw the child from the study. In 
this situation, xenon treatment will then be stopped as soon as possible and medically safe (within minutes). 
 
 
5.1 
Inclusion Criteria  
Patients meeting the following criteria will be considered eligible for the study: 
 
Infants will be eligible for inclusion in this study if the St Michael’s hospital standard inclusion criteria for cooling are 
met and additional inclusion criteria for xenon administration are met. 
 
St Michael’s hospital standard inclusion criteria for cooling 
Standard Hypothermia Treatment Criteria for 72 hrs of cooling  —  all of criteria A, B,  and C. 
A   Infants > 36.0 weeks gestation (clinical assessment) with at least ONE of the following:  
  
1        
Apgar score of <5 at ten (10) minutes after birth  

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2    
Continued need for resuscitation, including endotracheal or mask ventilation, at ten minutes after 
birth  
 
 
3 
Acidosis defined as either umbilical cord pH or any arterial, venous or capillary pH within 60 minutes 
of birth less than pH 7.00 
 
4 
Base deficit greater than or equal to 16 mmol/L in umbilical cord blood sample or any blood sample 
within 60 minutes of birth (arterial or venous blood). If the infant meets criterion A then assess for neurological 
abnormality using criterion B and C (by trained personnel): 
 
B 
Moderate or Severe encephalopathy as evidenced by any of the following --  
         
1 
Altered state of consciousness (reduced or absent responses or pathological irritability and hyper 
responsive and at least ONE or more of the following: 
 
2 
Hypotonia 
 
3 
Abnormal reflexes including oculomotor or pupillary abnormalities  
 
4 
Absent or weak suck  
 
5 
Clinical seizures, as recorded by trained personnel  
                                              And  
C 
At least 30 minutes duration of amplitude-integrated electroencephalography (aEEG) recording that shows 
abnormal background aEEG activity. The decision to cool is based on the worst section of the aEEG, not the best (al 
Naqeeb, et al, 1999) or seizures (clinical or electrical) thus meeting ONE of the following:  
 
1 
Normal background with some electrical seizure activity  
 
2 
Moderately abnormal activity (upper margin of trace >10μV and lower margin <5μV) 
 
3 
Suppressed activity (upper margin of trace <10μV and lower margin of trace <5μV) 
 
4 
Definite seizure activity 
------------------------------------------------------------------------------------ 
   
Additional inclusion criteria for xenon 
Before being considered for additional inhaled xenon therapy via the breathing gas mixture, the infant would need to 
meet further additional entry criteria (all must be met): 
1) 
Intubated, ventilated, sedated, being cooled. 
2) 
<5 hours old 
3) 
Any seizures under control. 
4) 
Weight > 2nd centile for gestational age 
5) 
Stable cardiovascular parameters; Mean arterial pressure >40mmHg. 
6) 
Oxygen requirement via mechanical ventilator < 40%. 
7) 
Positive End Expiratory Pressure (PEEP) requirement < 6cm H2O 
8) 
Arterial/capillary/venous pCO2 <7.0kPa (ideally arterial).  Venous can be higher if peri-arrest and tissues 
have been very recently ischaemic 
9) 
Postnatal age <5 hours 
10) 
Absence of major congenital abnormalities, imperforate anus and in particular any bowel obstruction, 
congenital abnormalities suggestive of chromosomal anomaly or other syndromes that include brain 
dysgenesis. Neonates with congenital syndromes affecting the brain should be excluded when diagnosed 
(see exclusion criteria below) 
 
 
5.2 
Exclusion Criteria 
 
 
Exclusion criteria for cooling 
1. 
Infants expected to be greater than 5 hours of age at the time of starting cooling treatment. 
2. 
Futility. Where prognosis is considered to be hopeless e.g. no cardiac output for 20 minutes. 
 
Additional exclusion criteria for xenon 

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Failure to meet any of the additional inclusion criteria for xenon listed in section 5.1. 
Patients meeting the following criteria are NOT eligible for the study: 
Presence of any of: 
Major congenital abnormalities, imperforate anus and in particular any bowel obstruction, congenital abnormalities 
suggestive of chromosomal anomaly or other syndromes that include brain dysgenesis. (Neonates with congenital 
syndromes affecting the brain should be excluded when diagnosed). 
 
 
5.3 
Prohibited Therapies 
Not Applicable. 
6.0 
Subject Assignment to Treatment Group 
The babies entered into the study will be randomised into groups; xenon+cooling or cooling (standard treatment) 
alone. Neonates meeting all the entry criteria can be included. 
 
Immediately after enrolment, the patient will be assigned a study ID number, chronologically, from a specified series on 
an enrolment log specific to the Investigational Site. The Subject's study number and date of enrolment will be entered 
onto the enrolment log in the Study Binder. 
 
The babies entered into the study will be randomised into two groups on a 1:1 basis. Randomisation will be via sealed 
opaque envelopes containing details of treatment allocation and [an] identifying adhesive label(s) to be attached to the 
CRF binder. Neonates meeting all the entry criteria can be included. 
 
7.0 
Methods and Procedures 
7.1 
Informed Consent 
Informed written consent will be obtained from a parent (only the mother can consent if parents are not married) after 
a full verbal and written explanation of the study by a named physician or trained nurse such as an advanced nurse 
practitioner. Such staff will also meet with parents during the intervention period to ensure that they understand the 
study procedures and continue to consent to participate in the study. Information can be given by local trained staff 
and consent can also be taken over the phone with the mother if she is unable to be available for the consent process 
(e.g. cannot be moved shortly after Caesarean Section). 
Approval for the study is being obtained from the Regional South West Research Ethics Committee covering St 
Michael’s Hospital. 
Most of the patients will be born outside the study hospital (Outborn). Outborn patients are estimated to be >90% of 
patients. They are brought to the hospital by a dedicated retrieval team and ambulance from Bristol. 
The local delivery hospitals will have medical staff (e.g. consultants, specialist registrars, advanced nurse practitioners) 
trained in consenting for the CoolXenon2 trial. A training log with signatures, a short CV and competency approval will 
be kept centrally. 
Parents will receive a written information leaflet (1 page, short version) when the infant is eligible for cooling 
treatment. Staff will discuss CoolXenon2 with parents as soon as practically possible. Parents will be able to speak on 
the phone to a member of the treatment team if they need further information and help with the consent process. 
Parents will also be offered the opportunity to speak to members of the treatment team that are picking up the baby 
for transport. 
Trained staff on the transport team can take consent for the study. 
A more detailed information sheet regarding the trial will be given to parents after the first conversation or at the 
earliest suitable time. 
Which of the parents can consent to letting the child enter the trial? 
• 
Either parent if they are married 
• 
If the parents are not married, only the mother can consent - provided she is awake and understanding (eg not 
under the influence of anaesthetic drugs) 

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• 
If the mother is not in a state to understand the situation  and the biological father does currently not have 
legal parental responsibility he can assent for the trial until the mother is awake/understanding the childs 
condition  and able to decide on consent. 
A parent who is eligible to consent can, at any time and without a specific reason, withdraw the child from the study. In 
this situation, xenon treatment will then be stopped as soon as possible and medically safe (within minutes). 
 
 
7.2 
Pre-Study   
Consent will be obtained as described above from parents of the neonates. Prior to this consent they will have been 
given an information leaflet describing the study and the discussion will have taken place with a Consultant 
Neonatologist (Prof Marianne Thoresen or Dr James Tooley) involved in the study or a trained member of the Transport 
team. 
 
7.3 
Screening 
All infants born in St. Michael’s Hospital or retrieved by ambulance from other centres to St. Michael’s Hospital 
Neonatal ICU will have undergone a basic screen of their condition at birth as part of standard procedures, the 
commonest example being the APGAR scoring system, cord blood analysis and clinical examination. Any infant 
suspected of being in a poor condition at birth will, by  locally present  neonatal staff, be assessed for possible cooling 
as a treatment to limit brain injury using the  approved entry criteria (as used in CoolCap and TOBY). Local hospitals will 
typically contact  the St Michaels team within 1 h of age to discuss eligibility, start cooling, transport and potential 
inclusion in Xenon study. At this point on advice from Bristol, information on the xenon study can be given to parents.  
 
7.4 
Initial Assessment 
The following information will be recorded on the appropriate CRFs: 
7.4.1 
Demographics 
PATIENT 
• Date of birth   
• LMP last menstrual period 
• EDD expected date of delivery 
• Gestational age  weeks, days e.g 40 weeks, 3 days 
• Race  
• Gender 
• Weight 
MATERNAL 
• Years in education 
• Labour induced on maternal indication? 
• Maternal medical treatment during pregnancy 
7.4.2 
Patient History and Physical 
• 
Delivery and resuscitation details , Review of Systems,  Transport details if retrieved from another centre, 
Current  diagnoses 
•              Clinical examination 
7.4.3 
Concomitant Medications 
All concomitant medications will be recorded as follows: 
• Medication; Start (and Stop date(s) if applicable); Indication; Dose   
 
 

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7.5  
Study Phases 
The study consists of:  
7.5.1 
Phase 1  
Identification of potential subjects – initially using same identification method used in St. Michael’s Hospital Bristol to 
identify infants who would benefit from cooling.  
 
Compliance with all inclusion/exclusion criteria for use of xenon in addition to cooling (the standard treatment).  
 
7.5.2 
Phase 2  
Formal recruitment, information supplied to / discussions with parents. 
Consent. 
 
7.5.3 
Phase 3  
Completion of all screening / demographics / baseline data collection immediately pre-xenon, reintubation with cuffed 
tube, x-ray for tube placement and blood gas  
 
Administration of 50% xenon for 18 hours to infant according to randomisation protocol. 
 
Completion of all data collection, serum chemistry and examinations immediately post-xenon and post-cooling. 
 
 
7.5.4 
Patient Follow-up 
Short term information and investigations (before discharge from hospital): 
These are part of routine clinical practice. 
 
1. 
Survival 
2.  
Duration of hospitalisation 
3. 
Time to full oral feeds, breast or bottle 
4. 
Hypoxic-ischaemic or other injury on MRI scan (standard sequences for this injury) preferably aged 7-12 days 
of age and Magnetic Resonance Spectroscopy as a part of the MRI examination if available 
5.  
Intracranial or intraventricular haemorrhage (on MRI, CT or ultrasound) 
6.  
Major venous thrombosis (on MRI or ultrasound) 
7. 
Resistance Index (Doppler examination of cerebral blood flow velocities) 
8. 
Amplitude integrated EEG (aEEG) continuously recorded until after rewarming. Assessment of time to 
normalisation of background activity, seizure occurrence and duration 
9.  
Pulmonary hypertension needing treatment 
10.  
Pulmonary haemorrhage  
11.  
Pneumonia 
12.  
Pulmonary air leak 
13.  
Systemic hypotension needing inotropic support 
14.  
Prolonged blood coagulation time assessed before xenon and at ~24 hours and/or at clinically indicated  
timepoints 
15.  
Cardiac arrhythmia (not temperature induced low Heart Rate) 
16.  
Thrombocytopenia (platelets <100,000/ul) 
17.  
Culture proven sepsis 
18.  
Necrotising enterocolitis, medical, radiological or surgically proven  
19. 
Plasma markers of global (increased lactate dehydrogenase (LDH)) or cardiac compromise (increased cardiac 
Troponin T (cTnT)) 
20.  
Renal failure treated with dialysis 
 
 
 

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 Short term assessment neurological evaluation will include: 
1) Time to recovery after birth of a normal aEEG [1]  
2) MRI scan before 14 days of life [33, 2, 44]  
3) Peak LDH value within 72h of life [4, 34]  
 
We will also  collect data on: 
4) First plasma glucose after birth (usually from cord blood) 
5) Age in hours after birth  when plasma lactate has declined to <5mmol/l 
6) Number and type of inotropic drugs needed during stay on the neonatal intensive care unit (typically the period 
from birth to 3-5 days of age) and the total duration in hours of any inotropic support 
7) Number of anticonvulsant drugs given during stay on the neonatal intensive care unit. 
8) Amount and duration of sedation (eg morphine) while ventilated mechanically on the neonatal intensive care unit. 
9) Age at full oral feeds (breast or bottle or tube) 
10) Outcomes of neonatal hearing screening before 14 days of life 
11) Clinical examination at birth, at 7 days of age and at discharge including weight and head circumference 
Long term follow up (at 18 months) 
Neurodevelopmental follow up is a part of the routine follow up of infants with Neonatal Encephalopathy.  Bayley II 
examination at 18 months of age is used to compare the results from this study with our large local patient database 
and previous randomised controlled trials (CoolCap, Gluckman 2005; TOBY, Azzopardi 2009) [10, 11] where Bayley II 
was also used: we were a main recruiting centre for these trials. 
 
Disability will be defined as any of: 
Bayley II mental developmental scale score (MDI) less than 70. 
Bayley II motor development scale score (PDI) less than 70.  MDI and PDI will also be calculated as developmental 
quotients (DQ), as this allows a larger range of score for those functioning at a low level [35].                                   
Bilateral cortical visual impairments.  
Hearing loss needing amplification > 40 DB. 
 
Additionally: 
We will do both short-term (14 days) and long-term (18 months survival) follow-up.  In cooled babies we have shown 
that short-term predictors such as MRI at ~day 8 [2], time to normalisation of  aEEG [1] and peak LDH before 72h [4] 
predict long-term outcome with a positive predictive value of 84%, 92% and 80% respectively.  In this study we will be 
able to examine these predictors for cooled babies receiving xenon treatment.  By defining these relationships one can 
calculate the sample size for a large trial using short-term outcome. 
 
 
7.6 
Study Data 
All the patient study information will be coded by patient study number, anonymised and securely stored until the 
study is complete. Electronic data will be stored on a secure portion of a Hospital Trust computer. The Chief 
Investigator will ensure that all the patient identifying details have been removed prior to statistical analyses being 
undertaken. 
The identification key linking study numbers to patient details will be kept by the CI (Prof Marianne Thoresen) in a 
locked filing cabinet in a locked office in the Neonatal Neuroscience office of St. Michael's Hospital Bristol, which also 
has two separate secure swipe card entry systems. 

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7.7 
GP Notification 
The General Practitioner will be informed via a letter of the participation of the infant in the study when the infant is 
discharged from hospital. 
 
8.0 
Assessment of Safety 
8.1  
Data Review Group. 
An external Data monitoring Group will be set up and appropriately constituted with clearly defined terms of reference. 
Their role will be to independently review the safety of the study after every 4th xenon patient has been recruited i.e. 
every  4 xenon babies and in the light of this make appropriate recommendations to the study team. 
The group will meet when every 4 xenon-treated babies have been enrolled.  The Data Monitoring Group will also meet 
in the event of a death, regardless of cause.  This meeting will take place within ~14 days of the death and recruitment 
into the study will continue in the meantime.  This meeting could be in person or take the form of a teleconference. 
N.B. In our previous neonatal feasibility/safety study of xenon+cooling a partial external committee met at intervals of 
every other baby enrolled. One outcome of this study was that the xenon gas itself did not cause any significant 
physiological or biochemical changes or other problems and neither did the use of a breathing system functionally the 
same as the one to be used in this study. This explains our choice of a 4 enrolled xenon baby interval for the 
xenon+cooling group in this study. 
 
8.2 
Composition of Data Review Group 
External Members (not involved with delivering the treatment) 
 
 
 
Dr David Evans BM BCh (Oxon) MA (Cantab) MRCP(UK) FRCPCH 
Consultant Neonatologist 
North Bristol NHS Trust 
Neonatal Intensive Care Unit  
Southmead Hospital  
  
Bristol BS10 5NB UK 
  
 
 
david.evans@nbt.nhs.uk 
 
 
david.evans@bristol.ac.uk 
 
 
Professor Colin Morley 
Professor of Neonatal Medicine (Retired) 
23 High St, Great Shelford, Cambridge 
CB22 5EH UK 
 
UK mobile: 07591647097 
UK home phone: 01223846944 
colin@morleys.net 
 
 
Dr Steven Jones MB FRCPCH 
Director Southwest Neonatal Network 
Consultant Neonatologist Royal United Hospitals  
Coombe Park 
Bath BA1 3NG 
 Steve.Jones@RUH.nhs.uk 
 
Tel: 01225 825405 

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Lay member: 
 
Paula Windsor  BMedSci (Hons)  SR Paramedic 
School House 
Peter Street  
Frocester 
Glos    GL10 3TQ 
Tel: 01453 822833 
paulaascott@hotmail.com  
 
 
Dr Steven Sale MB ChB FRCA 
  
Paediatric Anaesthetist 
University Hospitals Bristol NHS Foundation Trust 
Bristol Royal Hospital for Children 
 
Upper Maudlin Street 
Bristol   BS2 8BJ 
 
 
steven.sale@uhbristol.nhs.uk 
 
 
 
 
The Data Monitor Group can invite one member from the research team to attend their meeting:  
 
Professor Marianne Thoresen MD PhD FRCPCH 
 
Professor of Neonatal Neuroscience, University of Bristol 
Honorary Consultant Neonatologist, University Hospitals Bristol NHS Foundation Trust 
Dept of Clinical Science at South Bristol, Child Health 
Level D, St Michael’s Hospital 
Southwell Street, Bristol  BS2 8EG 
 
marianne.thoresen@bristol.ac.uk  
 
Dr John Dingley MD FRCA 
  
Reader in Anaesthetics, University of Swansea 
Consultant Anaesthetist 
Honorary Consultant Anaesthetist University Hospitals Bristol NHS Foundation Trust 
Department of Anaesthetics and Intensive Care 
Morriston Hospital, Swansea SA6 6NL 
 
 
JDingley98@aol.com 
Dr James Tooley MBBS MRCP MRCPCH   
  
Consultant Neonatologist, University Hospitals Bristol NHS Foundation Trust 
Clinical lead, Department of Neonatal Intensive Care 
Level D, St Michael’s Hospital 
Southwell Street, Bristol  BS2 8EG 
 
James.Tooley@UHBristol.nhs.uk 
 
Or other named individuals in the research team 
 
 

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The Data Review Group will meet to assess the data from each enrolled infant at intervals of every 4th enrolled 
xenon+cooling infant or greater.  
 
8.3 
Criteria for stopping the study (stopping rule) have been developed according to the following logic: 
 
The underlying mortality is approximately 25% in this cohort of infants (without xenon). Usually care is redirected  
based on futility, i.e. the clinical condition and state of the brain is such that no meaningful life can be expected. 
 
Reasons for stopping Xe delivery before the 18h timepoint: 
Cardiovascular problems sometimes present as untreatable hypotension. In this situation the heart has also suffered 
hypoxia-ischaemia and sometimes we are unable to keep a perfusion pressure even with the use of maximum inotropic 
support. 
 
Another problem would be if the neonate develops a very high oxygen fraction (up to 100%) in the breathing gas over 
time, >40% according to the study entry criteria. An example would be those who have aspirated meconium.  
 
                            
Stopping rule: 
 
Mortality since cooling became standard of care at St Michaels hospital (inborn and outborn) fell from 34%to 25%. With 
this (25%) underlying mortality it is not unlikely, for example, that the two first infants might die (p= 0.06). If the study 
is allowed to continue and also the third infant in the xenon group dies, the probability that this is a random event is 
very small (p=0.016) and recruitment should be stopped and the protocol reviewed.  
 
From then on (n is the number of ‘xenon’ babies included in the study):  
 
  n    deaths  
 
  3    3 of   3  stop 
  4    3 of   4  stop 
  5    4 of   5  stop 
  6    4 of   6  stop 
  7    4 of   7  stop 
  8    5 of   8  stop 
  9    5 of   9  stop 
10    5 of 10  stop 
11    5 of 11  stop  
12   6 of 12  stop  
-------------------------------------------------------- 
If a few more than 12 infants were to be included in the xenon arm of this study the number of deaths used 
as the stopping number should be 40% of the total number.  
 
This stopping rule is based on two considerations:  
 
1. Probabilities given 25 % mortality without Xe 
2. Stricter rule with more babies included 
 
(See Appendix A6) 

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8.4 
Adverse Events (AEs) 
Adverse events will be recorded in accordance with UH Bristol’s Research Related Adverse Event Reporting Policy. 
8.5 
AE Definitions 
Adverse event 
“Any untoward medical occurrence in a patient or clinical trial subject administered a medicinal product and which 
does not necessarily have a causal relationship with this treatment” 
 
Adverse reactions 
“All untoward and unintended responses to an investigational product related to any dose administered” 
 
Serious adverse event 
“Any untoward medical occurrence or effect that at any dose results in death, is life – threatening, requires 
hospitalisation or prolongation of existing hospitalisation, results in persistent or significant disability or incapacity or is 
a congenital anomaly or birth defect.” 
 
Unexpected adverse reaction 
“An adverse reaction, the nature or severity of which is not consistent with the applicable product information (e.g. 
investigator’s brochure for an unauthorised medicinal product or summary of product characteristics for an authorised 
product)” 
 
Assessment of causality 
 
1. Not related – temporal relationship of the onset of the event, relative to the administration of the product, is 
not reasonable or another cause can by itself explain the occurrence of the event. 
 
2.  Unlikely 
 
3. Possibly related – temporal relationship of the onset of the event, relative to administration of the product, is 
reasonable but the event could have been due to another, equally likely cause. 
 
4. Probably related – temporal relationship of the onset of the event, relative to the administration of the 
product, is reasonable and the event is more likely explained by the product than by another cause. 
 
5. Definitely related – temporal relationship of the onset of the event, relative to the administration of the 
product, is reasonable and there is no other cause to explain the event or a re challenge (if feasible) is positive. 
 
 
 Of the above definitions,  
“possibly”, “probably” and “definitely” related to an investigational medical product are considered adverse reactions 
“unlikely” and “not related” do not qualify as a causal relationship. 
 
The severity and causality of a serious adverse event, adverse event or SUSAR (Suspected Unexpected Serious Adverse 
Reaction) should be assessed by a qualified medical practitioner, usually (but not always) the Chief Investigator (CI). 
 
Adverse events or reactions that are not life threatening and do not result in death or hospitalisation may also be 
considered serious if they jeopardise the subject or require intervention. 
 
All adverse events must be reported to the sponsor immediately, unless they are identified as not requiring this in the 
trial protocol.  
It is then the responsibility of the sponsor to report the incident to the MHRA  

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8.6 
AE Classification 
The Investigator(s) will establish the causality of AEs. 
8.7 
AE Recording 
All Adverse Events volunteered by study Patients or elicited by the Investigator must be recorded on the AE forms 
provided.  All AEs must be recorded whether or not considered drug / treatment related. 
8.8 
AE Reporting 
The Investigator must report by telephone all serious AEs to the Sponsor immediately upon discovery, and forward the 
completed AE form as soon as it is available.  If the event has been classified serious / severe, or there is any suspicion 
that the AE was caused by a test article, details of medical history, concomitant medication and an assessment of 
compliance with therapy should accompany the AE form.  The Investigator must also report the resolution reported AEs 
promptly.  
Non-serious AEs should be reported at the next routine contact. 
The time period allowed for reporting such events to the MHRA are as follows: 
Reaction which is fatal or life threatening, as soon as possible but no later than 7 days after first occurrence 
Reaction which results in hospitalisation /disability/congenital anomaly, as soon as possible, but no later than 15 days 
after first occurrence 
 
8.9 
Reporting Responsibilities to Regulatory Authorities, Investigators and Ethics Committees 
The study will be performed subject to Research Ethics Committee (REC) approval, including any provisions of Site 
Specific Assessment (SSA), and local Research and Development (R&D) approval.  The Sponsor will send appropriate 
safety notifications to regulatory authorities in accordance with applicable laws and regulations. 
The Investigator must comply with any applicable site-specific requirements related to the reporting of SAEs involving 
his/her subjects to the Ethics Committee that approved the trial. 
In accordance with ICH GCP guidelines, the Sponsor will inform the Investigator of “findings that could adversely affect 
the safety of subjects, impact the conduct of the trial or alter the Ethics Committee approval to continue the trial”. 
9.0 
Data Analysis and Statistical Plan 
9.1 
Statistical Analysis 
This is a randomised pilot study. Data presentation will include descriptive statistics only. These will be compared in the 
2 treatment groups but also to recordings of the same variables in a similar group of 45 infants (recruited to cooling 
only from the same entry criteria) recently treated in our department (historical control data). Differences between the 
groups will be estimated 
Sample size is 16 infants in each group. In accordance with the paper by Julious (Appendix 11), 12 is  a large enough 
number to estimate the mean value of short term outcome variables  for the group. The study does of course not have 
the power to test outcome. The main purpose of this randomised pilot study is to examine whether early recruitment  
is feasible, secondly whether the short term biological markers show the expected range  of values  in the cooled only 
group as compared to our historical controls.  Our advisory  statistician  for this study  is Professor Lars Walloe who also 
advised all our experimental xenon work as well as the recent clinical feasibility study. 
 
9.2 
Interim Analysis and Stopping Rules 
See 8.0 – 8.3 above which describes interim analysis and stopping rules in detail. 
10.0 
Withdrawal of Subjects from Study 
Patients may be withdrawn from the study for any of the following reasons: 
• 
Experiences clinically significant Adverse Event as determined by the Chief Investigator 
• 
Requests to be withdrawn from the study  
• 
Is unable to complete the study because of unforeseen circumstances 

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• 
Develops other conditions for which, in the Investigator’s opinion, it is in the Patient’s best interest to be 
withdrawn from the study 
 
11.0 
Modification of Protocol 
Any amendments to this protocol must be approved by the appropriate Research Ethics Committee, MHRA, Sponsor 
and the Investigators. 
 
12.0 
Discontinuation of Study 
See “stopping rule” in section 8 above. 
 
13.0 
Administrative Requirements, Ethical and Regulatory Aspects and Quality Assurance 
13.1 
Study Approvals: MHRA, Research Ethics Committee (REC) and NHS Trust R&D Approval 
Before the study can begin the Chief Investigator must provide the Sponsor with: 
i. 
a signed copy of a letter of “No Objection” from the MHRA 
ii. 
a copy of the approval notice for the protocol from the appropriate Research Ethics Committee, signed by the 
Chairperson;  
iii. 
a copy of the research governance approval from the  University Hospitals Bristol NHS Foundation Trust. 
This study will be conducted in accordance with:  
• The Medicine for Human Use (Clinical Trial) Regulations 2004.  
• International Conference for Harmonisation of Good Clinical Practice (ICH GCP) guidelines.  
• Research Governance Framework for Health and Social Care  
 
13.2 
Responsibilities of the Investigator 
The Investigator shall be responsible for ensuring that the clinical study is conducted in accordance with the protocol, 
the ethical principles enshrined in the Declaration of Helsinki (Appendix 9), ICH guidance on Good Clinical Practice and 
all applicable regulatory requirements.  
In all cases the informed consent of subjects or their legal representatives is an essential precondition for participation 
in any clinical study. 
13.3 
Subject Information 
An unconditional prerequisite for a subject participating in the clinical study is his/her written informed consent. 
Therefore, adequate information must be given to the subject by the Investigator (in this case parent) before informed 
consent is obtained. A subject information sheet will be provided by the Sponsor for the purpose of obtaining informed 
consent. In addition to this written information, the Investigator will verbally inform the subject. The wording used in 
the information sheet will be such that it can be fully and readily understood by laypersons. The subject information 
sheet will be revised whenever new information becomes available that is relevant to the consent of the subjects. 
13.4 
Subject Consent 
The written informed consent of the subject (in this case subject’s representative – a parent) to participate in the 
clinical study has to be given before any study-related activities are carried out. It must be signed and dated by the 
subject and by the Investigator or person designated by the Investigator to conduct the informed consent discussion. 
13.5 
Source Data and Subject Files 
The Investigator must keep a written subject file for every subject participating in the clinical study. In this subject file, 
the available demographic and medical information of a subject has to be documented, in particular the following: 
name, DOB, sex, height, weight, medical history, concomitant diseases and medications (including changes during the 
study), statement of entry into the study, study identification, randomisation number (if applicable), date of informed 
consent, all study visit dates, predefined performed examinations and clinical findings, observed AEs and reason(s) for 
withdrawal from the study, if applicable. 

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It should be possible to verify the inclusion and exclusion criteria for the study from the available data in the file. It must 
be possible to identify each subject by using this subject file.  
Additionally, any other documents with source data have to be filed. This includes ECG tracings, X-ray films, CT and MRI 
scans, laboratory value listings and QoL questionnaires. All these documents have to contain a subject identifier and 
details of the study procedure to which the document belongs.  
13.6 
Reporting and Recording of Data 
The data recorded during the course of this study must be documented on the Case report Forms (CRFs) and forwarded 
to the Sponsor. The Investigator must ensure the CRFs do not contain the names of any study subjects. All fields on the 
CRFs must be completed.  
All study data will be recorded on the CRFs.  All CRF’s must be made available to the Study Monitor as soon as they 
have been completed so that the validity and completeness of the forms can be determined.  Where possible all CRF 
data should originate from a verifiable medical record.  All data should be recorded in black ink on the CRF for ease of 
duplication, interpretation and analysis. 
Any corrections should be made by scoring through the original value with a single line and writing the new value next 
to the original entry with the Investigator initialling and dating the new entry.  Only the Investigator or designated staff 
may amend or otherwise alter any data entered onto the CRF.  In addition any changes must be made on all copies of 
the document so that there is no difference between copies. If the reason for the correction is not obvious then, when 
appropriate, a brief explanation of the reason for the correction should be made.  Correction fluids should never be 
used on any document.  Before providing copies of completed CRF’s to the Study Monitor, the Investigator should 
review their completeness, accuracy and legibility. The Chief Investigator must always retain a copy of all completed 
CRF’s in the site Study Master File. 
13.7 
Monitoring 
The study will be monitored and audited in accordance with UH Bristol’s policy. All trial related documents will be made 
available on request for monitoring and audit by UH Bristol, the relevant Research Ethics Committee and for inspection 
by the Medicines and Healthcare products Regulatory Authority or other licensing bodies. 
The Chief Investigator will permit the Study Monitor to visit the Investigational Site at regular intervals to review all the 
CRFs, study management and GCP compliance. 
During monitoring visits, the Study Monitor will: 
• 
Help resolve any problems 
• 
Examine CRFs for omission of data, compliance and possible AEs 
• 
Discuss inconsistencies in the study data 
• 
Ensure that all study materials are correctly stored and dispensed 
• 
Check adherence to the obligations of the Investigator 
• 
Review consent forms, in particular the date of consent and signature 
• 
Perform source data verification as described below 
In line with ICH guidelines, monitoring will include verification of data entered in the CRF against original subject 
records. This verification will be performed by direct access to the original subject records and the Sponsor guarantees 
that subject confidentiality will be respected at all times. Participation in this study will be taken as agreement to 
permit direct source data verification. The Study Monitor must be kept informed of all issues pertinent to the study.   
At the final monitoring visit the Study Monitor must resolve any outstanding data deficiencies and retrieve all used and 
unused test articles.  
13.8 
On-site Audits 
The various National Regulatory Authorities, and the Sponsor, in the person of a scientifically trained and properly 
authorised employee, have the right to inspect all study records, including source documents. In the event of a 
notification of audit being received, the Chief Investigator should immediately notify the Sponsor. 

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13.9 
Record Storage and Retention 
Data will be collected and retained in accordance with the Data Protection Act 1998. Study documents (paper and 
electronic) will be retained in a secure location during and after the trial has finished. All source documents will be 
retained for a period of 15 years following the end of the study. Where trial related information is documented in the 
medical records - those records will be identified by a 'Do not destroy before dd/mm/yyyy' label where date is 15 years 
after the last patient last visit.  Good clinical practice requires that a copy of all study data and documentation must be 
retained in the files of the responsible Investigator for a minimum of 15 years following notification by Sponsor that all 
Investigations (not merely the Investigators’ portion) are completed, terminated, or discontinued. If the Chief 
Investigator retires, relocates, or for other reasons withdraws from the responsibility of keeping the study records, 
custody must be transferred to a person who will accept responsibility.  
13.10 
Indemnity 
This is an NHS-sponsored research study. For NHS sponsored research HSG(96)48 reference no. 2 refers. If there is 
negligent harm during the clinical trial when the NHS body owes a duty of care to the person harmed, NHS Indemnity 
covers NHS staff, medical academic staff with honorary contracts, and those conducting the trial.  
NHS Indemnity does not offer no-fault compensation and is unable to agree in advance to pay compensation for non-
negligent harm.  Ex-gratia payments may be considered in the case of a claim. 
 
14.0 
Study Sponsor 
All costs associated with the running of the study will be borne by University Hospital Bristol NHS Foundation Trust. 
 
15.0 
Publication 
We intend to report / disseminate the results of the study in the following ways: 
Peer reviewed scientific journals. 
Internal report. 
Conference presentations. 
Publication on website. 
 

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16.0 
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