Cognitive, Behavioural and Blood Biomarker Assessment After Carbon Monoxide (CO) Exposure
Conditions: Carbon Monoxide Poisoning
Sponsor: St George's, University of London

 
Protocol Version 1.0 14.12.2019
 
 
 
 
 
 
FULL/LONG TITLE OF THE STUDY 
 
 
Cognitive, behavioural and blood 
biomarker assessment after carbon 
monoxide (CO) exposure  
SHORT STUDY TITLE / ACRONYM 
 
 
Cognitive and blood biomarker 
assessment after CO Exposure 
PROTOCOL VERSION NUMBER AND DATE 
 
 
Version number: 1.0 
14th December 2019 
IRAS Number: 
277742 
JRES Reference Number 
2019.0375 
CHIEF INVESTIGATOR 
Peter Jenkins 
This protocol has regard for the HRA guidance and order of content 
 
 

 
Protocol Version 1.0 14.12.2019
SIGNATURE PAGE 
The undersigned confirm that the following protocol has been agreed and accepted and that the Chief 
Investigator agrees to conduct the study in compliance with the approved protocol and will adhere to 
the principles outlined in the Declaration of Helsinki, the Sponsor’s SOPs, and other regulatory 
requirement. 
I agree to ensure that the confidential information contained in this document will not be used for any 
other purpose other than the evaluation or conduct of the investigation without the prior written consent 
of the Sponsor. 
I also confirm that I will make the findings of the study publicly available through publication or other 
dissemination tools without any unnecessary delay and that an honest accurate and transparent 
account of the study will be given; and that any discrepancies from the study as planned in this protocol 
will be explained. 
 
For and on behalf of the Study Sponsor: 
Signature:  
...................................................................................................... 
 
Date: 
....../....../...... 
Name (please print): 
...................................................................................................... 
 
 
Position: 
...................................................................................................... 
 
 
 
Chief Investigator: 
Signature:
 
 
Date: 
....../....../...... 
 
Name:         Peter Jenkins 
 
 
 
 
 

 
Protocol Version 1.0 14.12.2019
LIST of CONTENTS 
Page No. 
PROTOCOL COMPLIANCE DECLARATION 
1 
TITLE PAGE  
1 
RESEARCH REFERENCE NUMBERS 
 
1 
SIGNATURE PAGE 
2 
LIST OF CONTENTS  
3 
KEY STUDY CONTACTS 
4 
STUDY SUMMARY 
4 
FUNDING 
 
5 
ROLE OF SPONSOR AND FUNDER 
5 
ROLES & RESPONSIBILITIES OF STUDY GROUP AND INDIVIDUALS   
5 
STUDY FLOW CHART 
 
6 
ABBREVIATIONS 
7 
1. BACKGROUND 
 
8 
2. RATIONALE 
 
9 
3. THEORETICAL FRAMEWORK 
9 
4. RESEARCH QUESTION/AIM(S)  
10 
5. STUDY DESIGN/METHODS 
10 
6. STUDY SETTING 
11 
7. SAMPLE AND RECRUITMENT 
11 
8. ETHICAL AND REGULATORY COMPLIANCE 
14 
9. DISSEMINATION  POLICY 
16 
10. REFERENCES 
18 
11. APPENDICES 
19 
 
 

 
Protocol Version 1.0 14.12.2019
 
KEY STUDY CONTACTS 
Chief Investigator 
Dr Peter Jenkins 
Neurology Department 
Atkinson Morley Wing, St George’s Hopsital 
Blackshaw Road 
London SW17 0QT 
Tel: 02087254631 
email: peter.jenkins1@nhs.net 
Sponsor 
St Georges University Hospitals NHS Foundation Trust 
SPONSOR REPRESENTATIVE: 
 
Name:   Subhir Bedi, Head of Research Governance and Delivery 
SPONSOR CONTACT:  
Name:  Joe Montebello 
Address:   St George's Joint Research Enterprise Service, 
Hunter Wing, Ground Floor,   
St George's, University of London and St George's 
University Hospitals NHS Foundation Trust,      
Cranmer Terrace SW17 ORE 
Email:  researchgovernance@sgul.ac.uk 
Phone: 020 82666866 
Funder(s) 
This study is funded by the Gas Safety Trust  
 
STUDY SUMMARY 
Study Title 
Cognitive, behavioural and blood biomarker assessment 
after carbon monoxide (CO) exposure 
Internal ref. no. (or short title) 
Cognitive and blood biomarker assessment after CO 
Exposure 
Study Design 
Cohort observational 
Study Participants 
Individuals with proven raised levels of carboxyhaemoglobin 
(COHb) (>1.6% in non-smokers and >6.3% in smokers) or 
proven exposure to CO  
Exclusion criteria: 
• 
age <18 years 
• 
other significant neurological condition 
• 
smoke inhalation 
Planned Size of Sample (if applicable) 50 
Follow up duration (if applicable) 
NA 
Planned Study Period 
18 months 
Research Question/Aim(s) 
(1) To determine whether blood biomarkers sensitive to 
neuronal injury are elevated in the sub-acute to chronic 
period following confirmed environmental, non-fire 

 
Protocol Version 1.0 14.12.2019
related exposure to CO. 
(2) Establish whether the prevalence of neurological, 
cognitive and behavioural deficits associated with CO 
exposure can be estimated; 
(3) Develop a sensitive and specific neurocognitive testing 
battery for CO poisoning 
(4) Characterize the neurological, cognitive and behavioural 
impairments following a confirmed CO poisoning event  
FUNDING AND SUPPORT  
FUNDER(S) 
FINANCIAL AND NON FINANCIALSUPPORT 
GIVEN 
Gas Safety Trust  
4 More  
London Riverside 
London SE1 2AU 
Tel: 0207 706 5100 
Email: info@energynetworks.org 
Providing financial support for the study. 
Also providing support regarding dissemination of 
findings 
 
ROLES AND RESPONSIBILITIES OF STUDY MANAGEMENT COMMITEES/GROUPS & 
INDIVIDUALS 
Trial Steering Group: 
 
Membership will consist of personnel involved in daily operational issues in the management of the 
study and will act upon advice/recommendations received by the sponsor.  
Trial Steering Group 
Chair 
Dr Peter Jenkins, Neurology Consultant, Atkinson Morley Wing 
St George’s University Hospitals NHS Foundation Trust, London SW17 0QT 
Member 
Professor Richard Atkinson 
Population Health Research Institute 
St George's, University of London, Cranmer Terrace, London SW17 0RE 
Statistical support 
Member 
Ms Clara Bannister, 
Neurosciences Research Coordinator 
St George’s University Hospitals NHS Foundation Trust, London SW17 0QT 
Study support including administration, assessments and blood taking 
 
 
PROTOCOL CONTRIBUTORS 
The protocol was conceived and designed by Dr Peter Jenkins.  
The All-Party Parliamentary Carbon Monoxide Group (a government body with the aims of tackling 
carbon monoxide poisoning, improving government policy on carbon monoxide safety and to raise 
public awareness of this issue) supported the study proposal and will aid the dissemination of results.  
The Gas Safety Trust, the study funder, will aid dissemination of results but will not control study 
design, analysis, interpretation or manuscript writing.   
 

 
Protocol Version 1.0 14.12.2019
STUDY Schematic 
 
 
 
 
 
 
 
 
 
 
Patient identified as having  
COHb > 1.6% non-smokers 
or >6.3% smokers 
AND/OR 
confirmed CO exposure 
Meets eligibility criteria 
Information sheet provided 
Consent gained 
Detailed medical assessment 
30 minute cognitive assessment  
on tablet computer 
30 minute completion of  
behavioural questionnaires 
Blood samples taken as per  
laboratory procedures 
 
Blood samples analysed at 
University College London 
for biomarkers of  
neurodegeneration 
Data entered onto database 
End of study 
involvement for  
patient 
Yes 
No 

 
 Protocol Version 1.0 14.12.2019 
Page 7 of 21 
 
 
 
ABBREVIATIONS 
AE  
Adverse Event  
AR  
Adverse Reaction  
CI  
Chief Investigator  
CO 
Carbon Monoxide 
CRF  
Case Report Form  
GCP  
Good Clinical Practice  
GP  
General Practitioner  
HRA 
Health Research Authority  
ICF  
Informed Consent Form  
NHS  
National Health Service  
NIHR  
National Institute for Health Research  
PI  
Principal Investigator  
REC 
Research Ethics Committee 
SAE 
Serious Adverse Event 
SGUL 
St Georges, University of London 
SGHFT 
St Georges, University Hospitals NHS 
Foundation Trust 
JRES 
(St Georges) Joint Research and 
Enterprise Services 

 
 
 
Cognitive and blood biomarker assessment after CO Exposure 
 
 
 
Protocol Version 1.0 14.12.2019 
STUDY PROTOCOL 
Cognitive, behavioural and blood biomarker assessment after carbon monoxide (CO) exposure 
 
1 
BACKGROUND 
Carbon monoxide is estimated to cause around 30 deaths[1], 200 admissions[2] and 4000 presentations 
to Emergency Departments (EDs) each year in the UK[3]. In the longer term, CO poisoning is 
recognised to cause persistent neurological problems (including impairments of thinking and 
behavioural changes), which can develop days to weeks after the initial exposure[4]. However, the 
incidence of these long-term sequelae is unknown[4]. In addition, there is evidence of long-lasting 
inflammatory changes in the brain and on-going brain cell injury, although how long this persists is 
also unknown[5]. One long-term follow up study 33 years after a large CO poisoning mining accident 
showed over 70% of those affected had evidence of cerebral atrophy (loss of brain volume)[6], which 
may suggest evidence of persistent brain cell injury. 
Initial assessments of CO exposure can be unreliable if blood tests are not carried out within a 
relatively short period after the exposure[7] and other biomarkers (such as imaging[8]) are insensitive to 
detecting previous CO exposure. Furthermore, chronic low-level exposure to CO poisoning can cause 
significant neurological deficits even with relatively low CO blood levels[9]. 
Certain proteins that are found in brain cells can be detected in the blood of individuals following brain 
injury and brain cell death. These proteins have been found to be raised in the acute period after 
minor head injury[10], persistently raised in patients with a traumatic brain injury and evidence of on 
going neurodegeneration (i.e. on going brain cell death)[11] and in patients with various types of 
dementia[12].   
We will assess the presence of these proteins in the blood of 50 patients with proven CO exposure in 
the sub-acute to chronic timescale (2 weeks to 2 years). This has not been done before and will allow 
assessment of the presence of on going brain injury in these patients. We will also assess cognitive 
(e.g. memory, attention and speed of thinking) and behavioural impairments in these patients to help 
characterise the common impairments suffered following CO exposure.  
 
 
2 
RATIONALE 
 
2.1 Primary aim:  
To determine whether blood biomarkers sensitive to neuronal injury are elevated in the sub-acute to 
chronic period following confirmed environmental, non-fire related exposure to CO. 
 
2.2 Secondary aims: 
• 
Establish whether the prevalence of neurological, cognitive and behavioural deficits associated 
with CO exposure can be estimated; 
• 
Develop a sensitive and specific neurocognitive testing battery for CO poisoning 
• 
Characterize the neurological, cognitive and behavioural impairments following a confirmed 
CO poisoning event  

 
 
 
Cognitive and blood biomarker assessment after CO Exposure 
 
 
 
Protocol Version 1.0 14.12.2019 
Current methods for detecting neurological injury due to CO exposure are unreliable yet the 
importance of neurocognitive changes found in people who have suffered from CO exposure are well 
depicted in case study reports[13]. There is therefore a need to identify those patients with chronic 
neurological problems due to CO exposure.  
Measurements of certain proteins in the blood (in particular neurofilament light (NFL)) have become 
increasingly sensitive over recent years to detect the presence of injury to brain cells. These proteins 
are present inside brain cells and if the brain cells are injured they are released into the blood. These 
proteins have been found to be raised in the acute period after minor head injury[10], persistently raised 
in patients with a traumatic brain injury and evidence of on going neurodegeneration[11] and in patients 
with dementia[12]. Determining whether these blood biomarkers are raised following CO exposure is 
therefore important in order to be able to establish whether there is evidence of persistent brain injury 
in the sub-acute to chronic time frame after CO exposure.  
Currently, it can be hard to determine whether an individual has had CO exposure as COHb levels 
rapidly normalise and if not taken quickly following exposure will be normal. It is therefore important to 
determine whether there are key cognitive and/or behavioural impairments following CO exposure and 
how best to measure them.  
 
 
3 
THEORETICAL FRAMEWORK 
 
We will assess patients with proven exposure to CO in the sub-acute to chronic time period (2 weeks 
to 2 years after exposure). This will allow assessment of the use of blood biomarkers in this cohort that 
could be used in future patients with suspected but not proven CO exposure.   
We will also use a cognitive testing battery that is validated in traumatic brain injury patients and will 
determine whether it is useful at characterising a profile of cognitive impairment following CO 
exposure. 
 
 
4 
RESEARCH QUESTION/AIM(S) 
4.1 Primary aim:  
To determine whether blood biomarkers sensitive to neuronal injury are elevated in the sub-acute to 
chronic period following confirmed environmental, non-fire related exposure to CO. 
 
4.2 Secondary aims: 
• 
Establish whether the prevalence of neurological, cognitive and behavioural deficits associated 
with CO exposure can be estimated; 
• 
Develop a sensitive and specific neurocognitive testing battery for CO poisoning 

 
 
 
Cognitive and blood biomarker assessment after CO Exposure 
 
 
 
Protocol Version 1.0 14.12.2019 
• 
Characterize the neurological, cognitive and behavioural impairments following a confirmed 
CO poisoning event  
 
4.3 Outcomes: 
Blood biomarker levels in patients with proven CO exposure. 
Cognitive and behavioural profiles of patients with proven CO exposure 
 
 
5 
STUDY DESIGN and METHODS of DATA COLLECTION AND DATA ANALYIS 
 
The study will take place at St George’s Hospital. 
 
5.1 Methods: 
A prospective observational study of patients with confirmed CO exposure. All patients will be fully 
assessed with a full neurological assessment and examination, a detailed battery of cognitive tests, 
behavioural questionnaires and blood biomarkers sensitive to persistent neuronal (brain) injury: 
• 
The study will use Cogniclinic, a set of brief computerised cognitive tests that can be 
undertaken on a tablet computer which have been validated in other forms of acquired brain 
injuries including traumatic brain injury. This form of cognitive assessment benefits from the 
fact that it is easy to use and can be used in any setting. The App is free and was developed 
by researchers at Imperial College, London 
(https://quicktech.imperialinnovations.co.uk/i/software_apps/cognitron.html) 
 
• 
Patients will also complete a full set of validated behavioural questionnaires that assess quality 
of life, depressive symptoms, anxiety levels, post-traumatic stress symptoms, fatigue, apathy, 
return to work and a newly developed questionnaire that will aim to identify the presence of 
common post-CO exposure symptoms. 
 
• 
Two 4ml samples will be taken which will be sent to the UK Dementia Research Institute at 
UCL (Henrick Zetterberg’s Group) to test for neurological blood biomarkers. Research blood 
sample bottles will be labelled with a unique study identifier and processed according to study 
laboratory procedures. Blood samples will be sent to measure levels of protein biomarkers 
sensitive to neuronal injury. Neurofilament light (NfL) is a sensitive blood biomarker of 
persistent brain injury and neuronal loss. Increased levels are observed in a variety of 
neurodegenerative diseases, including Alzheimer’s disease and motor neuron disease. Levels 
also remain elevated in the chronic phase after a traumatic brain injury in some individuals and 
relate to evidence of progressive brain atrophy (shrinkage). This maybe relevant after CO 
exposure as some patients have progressive symptoms and it is a possible risk factor for the 
development of dementia. Blood biomarkers will include NfL, tau and glial fibrillary acidic 
protein.  

 
 
 
Cognitive and blood biomarker assessment after CO Exposure 
 
 
 
Protocol Version 1.0 14.12.2019 
Once enrolled, participants will be given a unique study identifier that will be used for all data 
collection, tests and blood samples. All data will be stored on a password-protected database on the 
Hospital’s servers accessible to just members of the research team. Statistical analysis will be 
conducted using SPSS and R. Data analysis will take place at St George’s hospital and with members 
of the research team based at St George’s University of London. The unique study identifier will be 
linked to the individuals’ personal data on a separate password-protected database held on the 
Hopsital’s servers. 
Cognitive tests and questionnaires will be compared to those from large normative control databases 
to identify differences between the study group (participants exposed to CO) and healthy controls. 
Blood tests will also be compared to a database of healthy controls to identify changes in these 
biomarkers after CO exposure.  
The relationship between the blood biomarkers and cognitive tests/behavioural questionnaires will 
also be analysed to see whether there is a correlation between cognitive/behavioural impairments and 
evidence of brain cell injury as identified by the blood biomarkers.  
Data collected from the cognitive tests and the questionnaires will be transcribed onto the main study 
database as soon after completion as possible. All results will be ascribed to the participants study 
identifier and no personal identifiable data will be included in the results database. Paper copies of the 
questionnaires will be kept with the participant files in a locked filing cabinet in a locked room. The 
blood samples will be sent as a batch with only the unique study identifier at the end of the study for 
analysis. No personal identifiable data will be sent with the blood samples. The results will be returned 
electronically via a password-protected encrypted database and transcribed to the main study 
database. 
The data will be archived according to the Sponsor’s standard operative procedure.  
 
 
6 
STUDY SETTING 
 
The study will take place at St George’s Hospital and is a single centre study. 
Patients will have confirmed CO exposure as detailed below and will be assessed in the sub-acute to 
chronic timeframe (2 weeks to 2 years post exposure). Participants will be considered eligible for 
enrolment into this study if they fulfil all of the inclusion criteria and none of the exclusion criteria as 
defined below. 
Participants will be identified via a National NHS clinic at St George’s Hospital, London that assesses 
and treats patients with previous CO exposure. 
 
 
7 
SAMPLE AND RECRUITMENT 

 
 
 
Cognitive and blood biomarker assessment after CO Exposure 
 
 
 
Protocol Version 1.0 14.12.2019 
 
7.1  
Eligibility Criteria 
50 individuals with confirmed evidence of CO exposure will be recruited. This will allow assessment of 
common sequelae after CO exposure.  
 
7.1.1 Inclusion criteria: 
• 
Individuals identified as having confirmed exposure to CO between 2 weeks to 2 years at time 
of assessment. CO exposure determined by either;  
• 
documented COHb levels above 1.6% in non-smokers and above 6.3% in smokers. 
• 
or, individuals with evidence of being exposed to raised levels of CO and symptoms  
7.1.2 Exclusion criteria: 
• 
age <18 years 
• 
actual or suspected smoke inhalation 
• 
significant neurological or psychiatric illness prior to CO exposure 
• 
inability to provide consent 
 
7.2  
Sampling 
 
7.2.1 Size of sample 
50 participants will be recruited. 
The average value for serum neurofilament light (NFL) in a large sample of healthy controls was 
22.9pg/ml (IQR 16.8-31.4) (Disanto G, Barro C, Benkert P, et al. Serum neurofilament light: a 
biomarker of neuronal damage in multiple sclerosis. Annals of neurology. 2017 Jun;81(6):857-70).  
Using a sample of size of 50 allows an effect size of 0.46 on serum NFL levels to be detected with 
power 0.9 and type 1 error rate of 5%. 
This sample size allows a relatively small change in serum NFL levels to be detected but as we do not 
know whether all CO exposed patients will have raised levels and we will have a range of levels of 
exposure, this sample size will allow us to explore these issues. 
 
7.2.2 Sampling technique 
A convenience sampling technique will be employed with participants identified via a National NHS 
clinic at St George’s Hospital, London that assesses and treats patients with previous CO exposure. 
All participants will have confirmed exposure to CO and individuals with only suspected exposure will 
not be included. If eligible for participation, patients will be provided with an information leaflet and 
asked if they would like to participate. Any individual with confirmed CO exposure can be referred into 
this clinic nationally. It is also linked to an on going study, the EDCO study (IRAS 248936), which is 
screening individuals for carbon monoxide exposure in emergency departments. Individuals identified 
as having been exposed to CO from this study will be offered a follow up in this clinic. This sampling 
technique has been used to optimise recruitment given the fact CO exposure is relatively rare. 

 
 
 
Cognitive and blood biomarker assessment after CO Exposure 
 
 
 
Protocol Version 1.0 14.12.2019 
 
7.2 
 Recruitment 
Patient recruitment will only commence once evidence of the following approval / essential documents 
are in place:  
1. REC approval  
2. Final sponsorship permissions, 
 
Participant Identification 
Potential participants will be reviewed in a specialist Neurology outpatient clinic designed to assess 
and manage patients exposed to CO with neurological problems. 
This clinic is linked to a current research study (the EDCO study, a study screening for carbon 
monoxide exposure in emergency departments). Patients identified as having been exposed to CO will 
be routinely referred in to this clinic for clinical care. The PI for this study is the clinical lead for this 
outpatient clinic and will therefore have access to identifiable personal data in order to provide the 
clinical care and will be able to review the medical records in order to be able to determine suitability. 
Any patient nationally with confirmed CO exposure can be referred to this clinic but recruitment to the 
study will only occur once patients are reviewed in the clinic and participants to the study will not be 
recruited via other channels. The clinic will be publicised so that other healthcare professionals are 
aware of it so that patients can be assessed and reviewed clinically.  
 
7.2.1 Consent 
The Principal Investigator (PI), or an appropriately trained member of the team will obtain informed 
consent. Eligible patients will be provided with a written patient information sheet describing the study 
and the study team will be available to answer any questions. The patient will be given adequate time 
to read the information and consider their participation in the study. Due to the perceived low risk, 
burden and minimally invasive nature of the study, consent will be sought during the same routine 
clinic appointment in which patients are approached about the study by the clinical team. If they wish 
to take part they will then go through the written consent process. 
The patient will be informed that their medical records are subject to review by representatives of the 
sponsor as necessary and that data will be collected and processed in accordance with the Data 
Protection Act 2018. The patient will be told that participation in the study is voluntary and that they 
are free to withdraw from the study at any time and without prejudice. If patients are willing to provide 
a reason for their withdrawal, this information will be recorded. Each patient will be advised that data 
collected may be published or presented at scientific meetings and may also be subject to audit 
procedures from Regulatory Authorities. All such personally identifiable data will be pseudo-
anonymised to maintain patient confidentiality.   
A copy of the signed Informed Consent Form (ICF) along with a copy of the most recent approved 
Patient Information Sheet (PIS) will be given to the study participant.  The original signed & dated 
consent form will be placed in the ISF and a copy retained in the medical notes.   

 
 
 
Cognitive and blood biomarker assessment after CO Exposure 
 
 
 
Protocol Version 1.0 14.12.2019 
If new information results in significant changes to the risk–benefit assessment, the consent form will 
be reviewed and updated if necessary. All participants, including those already being treated, will be 
informed of the new information, given a copy of the revised consent form and asked to re-consent if 
they choose to continue in the study. 
 
7.2.2 Data collection tool 
Paper Case Report Forms (CRFs) will be used. All data will be entered legibly in black ink with a ball-
point pen.  If the investigator makes an error, it will be crossed through with a single line in such a way 
to ensure that the original entry can still be read. The correct entry will then be clearly inserted. The 
amendment will be initialled and dated by the person making the correction immediately. Overwriting 
or use of correction fluid will not be permitted. 
It is the investigator’s responsibility to ensure the accuracy of all data entered and recorded in the 
CRFs. The delegation of responsibilities log will identify all study personnel responsible for data 
collection, entry, handling and managing the database. 
Patients will undergo a full medical history and examination. Data including COHb levels at time of 
exposure, medical and drug history will initially be entered into the medical notes as part of routine 
clinical care and if the participant wishes to take part in the study the relevant data will be transcribed 
onto the paper CRF. 
Behavioural questionnaires and cognitive assessment results will be entered into a password-
protected spreadsheet/database on the NHS computing network.  
 
7.2.3 Biological Sample Handling 
Sample collection 
Two samples of 4-5ml each to be collected from each participant: 
• 
Serum (gel tube). One 10 or 7mL tube 
• 
Plasma(EDTA-K2 tube, purple cap). One 10 or 7mL tube 
 
Processing at St George’s lab 
Tubs will be mixed by turning up and down 8-10 times. The serum sample will be allowed to coagulate 
for >30 min. 
Serum: 
After coagulation, it will be centrifuged at 2500 x g for 20 minutes with temperature set at +4°C. 
Plasma: 
It will be centrifuged at 2500 x g for 20 minutes with temperature set at +4°C. 
Aliquotation and storage 
0.5-1.0 mL aliquots of the samples will be pipetted into cryotubes. 
All tubes will be labelled (patient unique studyID, date etc.) and frozen immediately at -80oC. 

 
 
 
Cognitive and blood biomarker assessment after CO Exposure 
 
 
 
Protocol Version 1.0 14.12.2019 
Samples will be stored at St. George’s Hospital until all samples have been collected. Samples will 
then be sent in bulk by specialist courier to the UK Dementia Research Institute at UCL (Henrick 
Zetterberg’s Group) to test for neurological blood biomarkers. Upon completion of sample analysis, 
remaining sample material will be disposed in accordance with the Human Tissue Authority’s Code of 
Practice. 
 
7.3 Confidentiality 
All data will be handled in accordance with the Data Protection Act 2018. Only delegated members of 
the research team, who form part of the direct clinical care team will have access to patient identifiable 
data. 
Once written informed consent has been obtained for study participation, the patient will be allocated a 
unique study identifier (consisting of a site number and sequential participant number), which will be 
utilised to code all depersonalised data. The patient’s unique study number (ID) only, will be used for 
identification. 
As no personal identifiable data is being collected, there will be no personal identifiable data included 
in the results. 
 
7.4 Archiving arrangements 
The essential study documents along with the study database will be archived in accordance with the 
sponsor SOPs. The agreed archiving period for this study will be 10 years.  
 
7.5 Direct access to source data 
The investigator(s)/institution(s) will permit sponsor / study-related monitoring, audits, REC review, 
and regulatory inspection(s), providing direct access to source data/documents. Study participants are 
informed of this during the informed consent discussion. Participants will consent to provide access to 
their medical notes. 
 
 
8 
ETHICAL AND REGULATORY CONSIDERATIONS 
 
The study will be conducted in compliance with the protocol as agreed by the Sponsor and which was 
given favourable opinion by the Research Ethics Committee (REC) and Health Research Authority 
(HRA).  
The Chief Investigator will be provided (via the Sponsor) with file indexes. The CI will be responsible 
for the maintenance of the TMF. 

 
 
 
Cognitive and blood biomarker assessment after CO Exposure 
 
 
 
Protocol Version 1.0 14.12.2019 
Within 90 days after the end of the study, the CI and Sponsor will ensure that the REC is notified that 
the study has finished by completing the Sponsor’s ‘End of study declaration’.  
The CI will supply an End of Study report of the clinical study to the REC within one year after the end 
of the study. If the study is ended prematurely, the Chief Investigator will notify the REC, including the 
reasons for the premature termination. 
 
8.1 
Assessment and management of risk 
Participants will be identified and recruited via a specialist neurology clinic treating patients with CO 
exposure. If the research team identify concerns regarding potential harm to the patient, e.g. concerns 
regarding the participant’s mental health, then these will be discussed with the research team clinician 
(Dr Peter Jenkins) and appropriate action taken. A similar management plan will be instituted if the 
participant discloses information about intention to harm others to members of the research team.  
 
8.2  
 Research Ethics Committee (REC) and other Regulatory review & reports 
Before the start of the study, a favourable opinion will be sought from an appropriate REC for the 
study protocol, informed consent forms and other relevant documents e.g. advertisements.  
• 
Substantial amendments that require review by NHS REC will not be implemented until that 
review is in place and other mechanisms are in place to implement at site.   
• 
It is the Chief Investigator’s responsibility to produce the annual reports and submit the REC 
within 30 days of the anniversary date on which the favourable opinion was given, and 
annually until the study is declared ended. 
• 
The Chief Investigator will notify the REC of the end of the study within one year after the 
end of the study. 
• 
If the study is ended prematurely, the Chief Investigator will notify the REC, including the 
reasons for the premature termination. 
 
Regulatory Review & Compliance  
Before any site can enrol patients into the study, the Chief Investigator/Principal Investigator or 
designee will ensure that appropriate approvals from participating organisations are in place. Specific 
arrangements on how to gain approval from participating organisations are in place and comply with 
the relevant guidance. 
Amendments  
For any amendment to the study, the Chief Investigator or designee, in agreement with the sponsor 
will submit information to the appropriate body in order for them to issue approval for the amendment. 
The Chief Investigator or designee will work with sites (R&D departments at NHS sites as well as the 
study delivery team) so they can put the necessary arrangements in place to implement the 
amendment to confirm their support for the study as amended. 
 
8.3  
Peer review 

 
 
 
Cognitive and blood biomarker assessment after CO Exposure 
 
 
 
Protocol Version 1.0 14.12.2019 
The study was peer reviewed via a competitive funding application by the funder, the Gas Safety 
Trust. Award of the funding entailed expert review and panel interview. 
 
8.4  
Patient & Public Involvement 
The grant proposal has been discussed and endorsed by the All-Party Parliamentary Carbon 
Monoxide Group which encompasses clinicians, policy makers and patient representatives/advocates. 
This group meets regularly and will allow feedback on the study and aid the dissemination of the 
findings. 
In addition, the funder of the study, the Gas Safety Trust, will aid dissemination of the results. 
 
8.5 
Protocol compliance  
Protocol deviations, non-compliances, or breaches are departures from the approved protocol. 
All protocol deviations must be adequately documented on the relevant forms and reported to the 
Chief Investigator and Sponsor immediately.  
Deviations from the protocol which are found to frequently recur are not acceptable, will require 
immediate action and could potentially be classified as a serious breach. 
 
8.6 Data protection and patient confidentiality  
All data will be handled in accordance with the Data Protection Act 2018 (UK implementation of the 
EU General Data Protection Regulation (GDPR)).  
Consent forms will be the only data collected during the study that will contain patient identifiable data. 
Once completed these will be stored in a locked filing cabinet in a locked office only accessible to 
delegated members of the research team. 
Any Case Report Forms (CRFs) will not bear the participant’s name or other directly identifiable data. 
The participant’s trial Identification Number (ID) only, will be used for identification. The Subject ID log 
can be used to cross reference participant’s identifiable information. The Subject ID log will be 
password-protected and stored on the St George’s Hospital servers. It will only be accessible to 
delegated members of the research team. 
Clinical data including cognitive testing and behavioural questionnaires will be uploaded to a 
password-protected database with the participant’s unique identifier. Clinical data will also include 
details of CO exposure (i.e. COHb levels), other medical history and medication history. Basic 
participant demographic data (e.g. gender, age, medical history) will also be recorded. Blood samples 
will be sent to the laboratory at UCL with no patient identifiable data and results will be sent back via 
secure email, again with no patient identifiable data. These results will be uploaded to the database. 
The database will be held on the St George’s Hospital IT infrastructure and will only be accessible to 
delegated members of the research team. The data will be kept for 10 years after the study and then 
deleted. 
Data will be analysed at both St George’s Hospital and also at St George’s University of London. Data 
will be transferred electronically via encrypted password-protected files to the University with no 
patient identifiable data (just the unique study identifiers).  
 
8.7 
Indemnity 

 
 
 
Cognitive and blood biomarker assessment after CO Exposure 
 
 
 
Protocol Version 1.0 14.12.2019 
St Georges University Hospitals NHS Foundation Trust is party to NHS Litigation Authority (NHSLA) / 
NHS Resolution. As an NHS body it is liable for clinical negligence and other negligent harm to 
individuals covered by their duty of care. NHS Institutions employing researchers are liable for 
negligent harm caused by the design of studies they initiate.  
 
8.8 
Access to the final study dataset 
Members of the research team will have access to the full dataset. Patients will be consented for 
possible secondary analysis through possible future research projects. 
 
9 
DISSEMINATION POLICY 
 
9.1 Dissemination policy 
Publication: “Any activity that discloses, outside of the circle of trial investigators, any final or interim data 
or results of the Trial, or any details of the Trial methodology that have not been made public by the 
Sponsor including, for example, presentations at symposia, national or regional professional meetings, 
publications in journals, theses or dissertations.” 
All scientific contributors to the Trial have a responsibility to ensure that results of scientific interest arising 
from Trial are appropriately published and disseminated. The Sponsor has a firm commitment to publish 
the results of the Trial in a transparent and unbiased manner without consideration for commercial 
objectives.  
To maximise the impact and scientific validity of the Trial, data shall be consolidated over the duration of 
the trial, reviewed internally among all investigators and not be submitted for publication prematurely. 
Lead in any publications arising from the Trial shall lie with the Sponsor in the first instance.  
 
Before the official completion of the Trial,  
All publications during this period are subject to permission by the Sponsor. If an investigator wishes to 
publish a sub-set of data without permission by the Sponsor during this period, the Study Management 
Group shall have the final say.  
Exempt from this requirement are student theses that can be submitted for confidential evaluation but are 
subject to embargo for a period not shorter than the anticipated remaining duration of the trial.      
 
Up to 180 days after the official completion of the Trial  
During this period the Chief Investigator shall liaise with all investigators and strive to consolidate data 
and results and submit a manuscript for peer-review with a view to publication in a reputable academic 
journal or similar outlet as the Main Publication.  
• 
The Chief Investigator shall be senior and corresponding author of the Main Publication.  
• 
Insofar as compatible with the policies of the publication outlet and good academic practice, 
the other Investigators shall be listed in alphabetic order.  
• 
Providers of analytical or technical services shall be acknowledged, but will only be listed as 
co-authors if their services were provided in a non-routine manner as part of a scientific 
collaboration.  

 
 
 
Cognitive and blood biomarker assessment after CO Exposure 
 
 
 
Protocol Version 1.0 14.12.2019 
• 
Members of the Study Management Group shall only be acknowledged as co-authors if they 
contributed in other capacities as well.   
• 
If there are disagreements about the substance, content, style, conclusions, or author list of 
the Main Publication, the Chief Investigator shall ask the Study Management Group to 
arbitrate.     
 
Beyond 180 days after the official completion of the Trial  
After the Main Publication or after 180 days from Trial end date any Investigator or group of investigators 
may prepare further publications.  In order to ensure that the Sponsor will be able to make comments and 
suggestions where pertinent, material for public dissemination will be submitted to the Sponsor for review 
at least sixty (60) days prior to submission for publication, public dissemination, or review by a publication 
committee. Sponsor’s reasonable comments shall be reflected. All publications related to the Trial shall 
credit the Chief and Co-Investigators as co-authors where this would be in accordance with normal 
academic practice and shall acknowledge the Sponsor and the Funders.    
 
9.2          Archiving Arrangements  
The trial essential TMF along with any central trial database will be archived in accordance with the 
sponsor SOP.  
 
 
 

 
 
 
Cognitive and blood biomarker assessment after CO Exposure 
 
 
 
Protocol Version 1.0 14.12.2019 
10 
REFERENCES 
 
1. 
Cross Government Group On Gas Safety And Carbon Monoxide (CO) Awareness. Annual 
Report. 2014-2015. 
2. 
Reducing the risk of carbon monoxide poisoning over winter [press release]. 2012. Available 
from: 
http://webarchive.nationalarchives.gov.uk/20140714084352/http://www.hpa.org.uk/NewsCentre/Nation
alPressReleases/2012PressReleases/121119Reducingtheriskofcarbonmonoxidepoisoning/ - 1._, 19 
November 2012 2012  
3. 
Carbon monoxide poisoning sends 4,000 people to A&E each year [press release]. 2011. 
Available from: https://http://www.gov.uk/government/news/carbon-monoxide-poisoning-sends-4-000-
people-to-a-e-each-year, 21/11/2011 2011. 
4. 
Weaver LK. Clinical practice. Carbon monoxide poisoning. N Engl J Med 2009; 360: 1217-25. 
5. 
Rose JJ, Wang L, Xu Q, McTiernan CF, Shiva S, Tejero J, et al. Carbon Monoxide Poisoning: 
Pathogenesis, Management, and Future Directions of Therapy. Am J Respir Crit Care Med 2017; 195: 
596-606. 
6. 
Mimura K, Harada M, Sumiyoshi S, Tohya G, Takagi M, Fujita E, et al. [Long-term follow-up 
study on sequelae of carbon monoxide poisoning; serial investigation 33 years after poisoning]. 
Seishin Shinkeigaku Zasshi 1999; 101: 592-618. 
7. 
Stoller KP. Hyperbaric oxygen and carbon monoxide poisoning: a critical review. Neurol Res 
2007; 29: 146-55. 
8. 
Beppu T. The role of MR imaging in assessment of brain damage from carbon monoxide 
poisoning: a review of the literature. AJNR Am J Neuroradiol 2014; 35: 625-31. 
9. 
Hampson NB, Piantadosi CA, Thom SR, Weaver LK. Practice recommendations in the 
diagnosis, management, and prevention of carbon monoxide poisoning. Am J Respir Crit Care Med 
2012; 186: 1095-101. 
10. 
Shahim P, Tegner Y, Wilson DH, Randall J, Skillback T, Pazooki D, et al. Blood biomarkers for 
brain injury in concussed professional ice hockey players. JAMA neurology 2014; 71: 684-92. 
11. 
Scott G, Zetterberg H, Jolly A, Cole JH, De Simoni S, Jenkins PO, et al. Minocycline reduces 
chronic microglial activation after brain trauma but increases neurodegeneration. Brain 2018; 141: 
459-71. 
12. 
Bacioglu M, Maia LF, Preische O, Schelle J, Apel A, Kaeser SA, et al. Neurofilament Light 
Chain in Blood and CSF as Marker of Disease Progression in Mouse Models and in 
Neurodegenerative Diseases. Neuron 2016; 91: 494-6. 
13. 
Lader M. Neuro-psychiatric complications of carbon monoxide poisoning. Curr Med Lit–
Psychiatry 2009; 20: 1-7. 
 
 

 
 
 
Cognitive and blood biomarker assessment after CO Exposure 
 
 
 
Protocol Version 1.0 14.12.2019 
 
 
11.  
APPENDICIES 
 
Appendix 1 
Amendment Log 
Amendment 
No. 
Protocol 
version no. 
Date issued 
Author(s) of 
changes 
Details of changes made