Standard Versus Flexible Tip Bougie for Videolaryngoscopy: A Randomised Comparison Between Standard and Flexible Tip Bougie (Tracheal Tube Introducers) for Tracheal Intubation Using Non Channelled Videolaryngoscope
Phase: NA
Conditions: Intubation, Intratracheal
Sponsor: University Hospitals Coventry and Warwickshire NHS Trust

 
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NCT04973176     Page 1 of 30 
 
 
 
 
 
Standard versus Flexible tip bougie for Videolaryngoscopy 
 
 
A randomised comparison between standard and flexible tip 
bougie (tracheal tube introducers) for tracheal intubation using non 
channelled videolaryngoscope. 
 
PROTOCOL 
IRAS number 
287767 
ClinicalTrials.gov number 
NCT04973176  
Sponsor 
University Hospitals Coventry & Warwickshire NHS Trust 
Sponsor reference 
<insert> 
Funder 
<insert if applicable> 
REC reference  
<insert> 
REC approval date 
<insert> 
HRA approval date 
<insert> 
Version number 
V1.0 
Date 
14.04.2021 
Planned Start date 
01.07.2021 
Planned End date 
30.12.2022 
Protocol Amendments 
Amendment Number 
Protocol Version Date of Amendment 
Date of Approval 

 
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Confidentiality statement 
All information contained within this document is regarded as, and must be kept, 
confidential. No part of this document may be disclosed to any Third Party without the 
written permission of the Chief Investigator and/or Sponsor. 
 
SIGNATURE PAGE 
The undersigned confirm that the following protocol has been agreed and accepted and that 
the Chief Investigator agrees to conduct the trial in compliance with the approved protocol 
and will adhere to the principles outlined in the UK Policy Framework for Health and Social 
Care Research, the ICH Good Clinical Practice guidelines and the Sponsor’s SOPs. 
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 clinical investigation 
without the prior written consent of the Sponsor. 
I also confirm that I will make the findings of the study publically 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: 

 
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Signature:  
 
 
Date:  
 
14/04/2021 
Name: Prof. Cyprian Mendonca 
Position: Consultant Anaesthetist 
 
 
KEY TRIAL CONTACTS 
Chief Investigator 
Professor Cyprian Mendonca 
Department of Anaesthesia 
University Hospital, Coventry, CV2 2DX 
Contact no: 02476964000 bleep 1865 
Principle Investigator Dr Charles Pairaudeau 
Department of Anaesthesia 
University Hospital, Coventry, CV2 2DX 
Email: Charles.Pairaudeau2@uhcw.nhs.uk 
Co-investigators 
Dr Thomas Moody, Dr Charles Pairaudeau 
Department of Anaesthesia 
University Hospital, Coventry, CV2 2DX 
Contact number 07972205555 
Email Thomas.moody@doctors.org.uk 
Sponsor 
University Hospitals Coventry & Warwickshire NHS Trust 
 
 
 
 
 
 
 
 
 

 
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 TRIAL SUMMARY 
 
Key Words: Intubation; tracheal, airway device; video laryngoscope 
 
Full study title 
A randomised comparison between standard and 
flexible tip bougie (tracheal tube introducers) for 
tracheal intubation using non channelled 
videolaryngoscope 
Short study title 
Standard vs flexible tip bougie for videolaryngoscopy 
Trial Design 
Randomised control Trial 
Trial Participants 
Patients aged 18 and above, presenting for elective 
surgical procedures where tracheal intubation is 
indicated   
Planned Sample Size 
160  
Follow up duration 
3 to 24 hours 
Planned Trial Period 
18 months 
 
Objectives 
Outcome Measures 
Primary 
Ease of tracheal 
intubation 
Modified Intubation Difficulty 
Scale Score 
Secondary 
Success rate at first 
attempt 
Laryngoscopy time 
Intubation time 
Additional 
manoeuvres required 
Bougie impingement 
Bougie rotation 
Post op sore throat 
between 3 -24 hours 
post op 
Success of tracheal 
intubation 

 
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STUDY FLOW CHART 
Figure 1: Flow of participants through the study 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Participant approached; information given  
Consent obtained 
Patient arrived into anaesthetic room 
Monitored, IV access secured  
Randomisation of patients into standard and flexible tip bougie groups 
Pre-oxygenated and GA induced, TOF applied and neuromuscular blockade 
given, absence of twitches on TOF 
Tracheal intubation using non channelled videolaryngoscope with standard 
or flexible tip bougie 
Study end- Rest of the anaesthetic procedure continued as normal 

 
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SCHEDULE OF OBSERVATIONS 
Table 1: Schedule of Events 
 
 
Procedure 
Screening Baseline 
Pre-
Op 
Intra-
Op 
Post-Op 
Eligibility assessment 
X 
X 
 
 
 
Informed consent 
 
X 
 
 
 
Demographic data (DOB, sex, height 
and weight)  
 
X 
 
 
 
Details regarding operative procedure, 
Anaesthesia and method of airway 
management 
 
 
X 
 
 
Airway Assessment 
 
 
 
X 
 
 
Randomistaion 
 
 
 
X 
 
Laryngoscopy, Tracheal Intubation 
Laryngoscopy time, intubation time 
and modified intubation difficulty score 
 
 
 
X 
 
Pot op visit- sore throat 
 
 
 
 
X 
 
 
 
 
 
 
 
 

 
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Contents 
SIGNATURE PAGE .................................................................................................... 2 
Key Words: Intubation; tracheal, airway device; video laryngoscope ......................... 4 
LIST OF ABBREVIATIONS ........................................................................................ 9 
1. 
INTRODUCTION ............................................................................................... 10 
2. 
RATIONALE ...................................................................................................... 12 
3. 
OBJECTIVES AND OUTCOME MEASURES/ENDPOINTS ............................. 13 
4. 
STUDY DESIGN ................................................................................................ 14 
5. 
STUDY SETTING .............................................................................................. 14 
6. 
ELIGIBILITY CRITERIA ..................................................................................... 14 
7. 
TRIAL PROCEDURES ...................................................................................... 15 
8. 
STATISTICS AND DATA ANALYSIS ................................................................ 18 
9. 
DATA MANAGEMENT ...................................................................................... 22 
10. 
TRIAL OVERSIGHT ....................................................................................... 23 
11. 
MONITORING, AUDIT & INSPECTION ......................................................... 24 
12. 
ETHICAL AND REGULATORY CONSIDERATIONS .................................... 24 
13. 
DISSEMINATION POLICY ............................................................................. 25 
14. 
REFERENCES ............................................................................................... 26 
 
 
 
 
 
 
 
 
 
 

 
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LIST OF ABBREVIATIONS 
 
AE 
Adverse Event 
CI 
Chief Investigator 
CRF 
Case Report Form 
CTA 
Clinical Trial Authorisation 
CTIMP 
Clinical Trial of Investigational Medicinal Product 
DMC 
Data Monitoring Committee 
EC 
European Commission 
EU 
European Union 
EudraCT 
European Clinical Trials Database 
GCP 
Good Clinical Practice 
ICF 
Informed Consent Form 
IDMC 
Independent Data Monitoring Committee 
ISF 
Investigator Site File 
MHRA 
Medicines and Healthcare products Regulatory Agency 
NHS R&D 
National Health Service Research & Development   
PI 
Principal Investigator 
PIS 
Participant Information Sheet 
RCT 
Randomised Control Trial 
REC 
Research Ethics Committee 
SAE 
Serious Adverse Event 
SAR 
Serious Adverse Reaction 
SDV 
Source Data Verification 
SSI 
Site Specific Information 
TMF 
Trial Master File 
TMG 
Trial Management Group 
TSC 
Trial Steering Committee 
 

 
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STUDY PROTOCOL 
 
 
A RANDOMISED COMPARISON BETWEEN STANDARD AND FLEXIBLE TIP 
BOUGIE (TRACHEAL TUBE INTRODUCERS) FOR TRACHEAL INTUBATION 
USING A NON CHANNELLED VIDEOLARYNGOSCOPE. 
 
 
 
1. 
INTRODUCTION 
Videolaryngoscopes are devices which aid successful intubation of the trachea. 
Unlike standard (direct) laryngoscopes, they include a camera at the tip of the blade 
and display unit to provide an indirect view of the vocal cords (glottis). They are now 
routinely used for both standard and anticipated difficult tracheal intubation [1] and 
are recommended for difficult intubation in the national guidelines [2]. Some 
videolaryngsocopes have channel as a guide to help with the placement of a 
tracheal tube and some are without channel. The non-channelled 
videolaryngoscopes with acute-angled blades require a bougie or stylet to facilitate 
the passage of tracheal tube through the glottis into the trachea.  One problem 
commonly encountered when using standard bougie is the tip of the bougie abutting 
on the anterior part of glottis and entrance to the windpipe (trachea) and not 
advancing further into the trachea [3]. This is known as anterior impingement. This 
can increase the likelihood of repeated intubation attempts, failed intubation and 
airway trauma.  C-Mac is a commonly used non-channelled videolaryngoscope and 
has been shown to have high first attempt success rate as compared to other 
videolaryngoscopes [4, 5] and acute angled D-blade require a bougie to facilitate 
tracheal intubation [6]. 
  
The recently introduced flexible tip bougie likely to over comes the problem of 
anterior impingement due to the ability to flex the tip in the posterior direction once 
the tip enter the glottis. In a manikin study [7], the paramedics were able to intubate 
the trachea more efficiently using flexible tip bougie as compared to standard bougie 
. We are not aware of any study comparing these devices for success of tracheal 
intubation in patients. Comparing the efficacy of these devices could help inform 

 
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anaesthetists decisions in future when faced with a potentially difficult airway and 
has the potential to update current difficult airway guidelines. 
 
1.1 Background 
 The recently introduced flexible tip bougie likely to overcome the problem of anterior 
impingement due to the ability to flex the tip in the posterior direction once the tip 
enter the glottis. In a manikin study [7], the paramedics were able to intubate the 
trachea more efficiently using flexible tip bougie as compared to standard bougie. 
We are not aware of any study comparing these devices for success of tracheal 
intubation in patients. Comparing the efficacy of these devices could help inform 
anaesthetists decisions in future when faced with a potentially difficult airway and 
has the potential to update current difficult airway guidelines. 
 
1.2  Proposed study 
We hypothesise that use of the flexible tip bougie will improve first attempt intubation 
success rates when compared to the standard bougie during laryngoscopy with non-
channelled videolaryngoscopes. The intubation success rate is measured using 
modified intubation difficulty scale score (Appendix1). The score includes the points 
given to number of attempts at intubation, minor problems noticed during intubation 
such as bougie impingement, need for bougie rotation, need for tube rotation and 
percentage of glottic view obtained.  
 
1.3  Study population 
Patients aged above 18, presenting for elective surgical procedures and requiring 
tracheal intubation will be invited to take part in the study. 
 
1.4 Treatment/ Intervention 
On arrival to theatre, following standard WHO surgical safety check list, patients 
will be randomly allocated to have tracheal intubation either using standard 
bougie or a flexible tip bougie.  The rest of the anaesthetic management will 
remain normal as planned by the lead anaesthetist. During tracheal intubation the 
data collected will included ease of tracheal intubation using modified intubation 
difficulty scale [8] and time taken to complete tracheal intubation.  

 
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1.5 Pre-clinical data 
In a manikin study [7], the paramedics were able to intubate the trachea more 
efficiently using flexible tip bougie as compared to standard bougie. 
1.6 Clinical Data 
 
Both the standard and flexible tip bougies are used in clinical practice at 
University Hospitals Coventry and Warwickshire NHS Trust. 
 
2. 
RATIONALE  
2.1 
Aims and hypothesis 
We hypothesise that use of the flexible tip bougie will improve the intubation success 
rates when compared to the standard bougie during laryngoscopy with non-
channelled videolaryngoscopes.  
 
2.2  
Justification 
 
The DAS (Difficult Airway Society) guidelines, state that the best intubation effort is 
the first one. It emphasises on choosing appropriate devices for first attempt, these 
include laryngoscope and bougie along with optimum position. When using a non-
channelled acute angled videolaryngoscope a bougie is essential to facilitate 
tracheal intubation.  The standard bougie consists of a rigid material normally with an 
acute curve at the distal end (coude tip), which is rigid and fixed. Hence, anterior 
impingement is a common problem.  The commonly used standard bougie is 14 
French gauge Frova® airway intubation catheter (William Cook Europe, Bjaeverskov, 
Denmark).  A flexible tip bougie (P3 medical Ltd, Bristol, UK) has a steerable blunt 
silicon tip and slider tabs which allows tip to be flexed anteriorly to facilitate the 
passage of the tip through the glottic opening, once advanced tip can be 
straightened or even retroflexed. Therefore, it can navigate around the curvature of a 
non-channelled videolaryngoscope more effectively. We are not aware of any study 
comparing this bougie with standard bougie for tracheal intubation when using 
videolaryngoscopes. A previous study looking at changing the head and neck 
position from traditional sniffing to neutral, didn’t make any difference in the success 

 
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rate [3]. Comparing the efficacy of different bougies during videolaryngoscopy could 
inform airway practitioners on their choice of bougie in both normal and difficult 
airway scenarios when using such laryngoscopes. 
 
2.3 
Assessment and management of risk  
For this study, patients requiring general anaesthesia and tracheal intubation for 
elective surgical procedures will be recruited. The videolaryngoscope (C-Mac non-
channelled videolaryngoscope) and bougies selected for this study are used in 
routine clinical practice as intubation aids. In the event of any unanticipated difficulty 
with intubation, the lead anaesthetist will follow the Difficult Airway Society 
guidelines. The data collection will stop at this point. 
 
The lead anaesthetist is free to choose a different airway equipment to those 
specified by the study, if they feel that this would be clinically appropriate. We do not 
anticipate any additional risks to the study participants.  During the procedure of 
airway management, all patients will be closely monitored as specified by 
Association of Anaesthetists’ standards of monitoring during anaesthesia. This 
includes peripheral oxygen saturation, end tidal oxygen, end-tidal CO2, ECG and 
blood pressure.  
 
3. 
OBJECTIVES AND OUTCOME MEASURES/ENDPOINTS 
3.1 
Primary objective 
The aim of the study will be to see which of two  bougies (an airway adjunct 
designed to pass through the vocal cords into the trachea in order to facilitate 
passage of a tracheal  tube) is best suited for tracheal intubation (passage of a 
breathing tube into the trachea) when using a non-channelled videolaryngoscopes.  
The primary outcome will be ease of tracheal intubation, assed using modified 
intubation difficulty scale (mIDS) score (Appendix 1). The initial version of this scale 
was described and validated by Adnet et al [5]. 
 
3.2 
Secondary objectives 

 
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Laryngoscopy time, time to successful tracheal intubation, overall first attempt 
success rate and visual analogue score for ease of use will be compared for two 
bougies.   
 
3.3 
Primary endpoint/outcome 
The reported ease of intubation as measured using the modified intubation difficulty 
scale score. 
 
3.4 
Secondary endpoints/outcomes 
• Time to successful tracheal intubation: It is time from when the 
videolaryngoscope is introduced into the oral cavity until the first capnography 
waveform is obtained. 
• Laryngoscopy time: It is time from when the videolaryngoscope is introduced 
into the oral cavity to best view of the glottis (vocal cords) 
• Overall first attempt success rate: This is the percentage of patients being 
successful at first attempt. This will be compared for two bougies.   
• Anaesthetist’s visual analogue score for ease of use of the bougie 
 
4. 
STUDY DESIGN 
Randomised Controlled  trial  
 
On arrival to theatre, following standard WHO surgical safety check list, patients will 
be randomly allocated to have tracheal intubation either using standard bougie or a 
flexible tip bougie. 
  
 
5. 
STUDY SETTING 
This will be a single centre study, conducted at University Hospitals Coventry & 
Warwickshire NHS Trust 
 
6. 
ELIGIBILITY CRITERIA 
Patients scheduled to undergo elective surgical procedures will be assessed for 
eligibility. 

 
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6.1 
Inclusion criteria 
Patients aged above 18, presenting for elective surgical procedures and requiring 
general anaesthesia tracheal intubation will be invited to take part in the study. 
6.2 
Exclusion criteria 
• Patients who are do not want to take part or do not give consent 
• Patients below 18 years of age 
• Patient physical status of ASA 4 and 5,  
• Patients deemed to require awake intubation 
 
 
7. 
TRIAL PROCEDURES  
Suitable patients for the study will be screened from the operating theatre lists. During 
the preoperative period, one of the research team members will explain the study and 
provide a patient information sheet. Patients will be given adequate time to read the 
information and any questions will be answered. If they are satisfied and willing to take 
part in the study, written consent will be obtained. 
7.1 
Recruitment 
The chief investigator and co-investigators will identify suitable operating lists on the 
and patients based on the scheduled surgical procedure. Only those patients 
meeting the inclusion criteria will be approached. 
7.1.1 Patient identification 
Patients undergoing surgery that requires tracheal intubation are suitable for inclusion 
in the study. Scheduled operating lists will be screened by the chief investigator and 
principle investigator and suitable patients will be identified.  
During the preoperative assessment one of the research team member will provide a 
patient information sheet. Patients will be given adequate time to read the information 
and any questions will be answered. If they are satisfied and willing to take part in the 
study, written consent will be obtained. 
 
7.1.2 Payment 
There is no payment for any participant for taking part in the study 
 
7.2 
Consent  

 
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Participants will be given adequate time to read and understand the patient 
information leaflet. Once they have read the information, any questions will be 
answered. If they agree for the study, they will be asked to complete the consent 
form. The consent will be obtained by chief investigator, coinvestigator or one of the 
research team members, supervised by the investigators.  
 
7.3 
Randomisation scheme  
Sample size: From our previous study using CMAC VL and Frova bougie, the 
standard deviation was 0.95 and mean mIDS was 1.75. We considered a 30% 
reduction in mIDS to be clinically relevant. For standardized difference of 0.53, with a 
power of 0.9 and significance level of 0.05, we need 73 patients in each group. To 
account for failures and dropouts, we decided to recruit 160 patients in total.   
 
Randomisation for this study will be completed using sealed opaque envelopes. On 
arrival to the anaesthetic room, sealed envelope will be opened to reveal the group.  
Based on the group, following induction of general anaesthesia, the chosen bougie will 
be selected. It would be ensured that both type of bougies readily available in the 
airway trolley. Once the bougie is successfully placed in the trachea, tracheal 
intubation is completed as normal. 
 
On arrival in the anaesthetic room, patients will be monitored using peripheral 
oxygen saturation, end-tidal CO2, ECG and blood pressure. Both standard and 
flexible tip bougies will be kept ready for each study patient. Patient will be randomly 
allocated to one of two groups.  
1. Flexible tip bougie  
2. Standard bougie 
All patients will be pre-oxygenated in a 15 to 20o head up position, to achieve a 
fractional ETO2 of at least 0.8 prior to induction of anaesthesia.  General anaesthesia 
will be induced at the discretion of lead anaesthetist. After the loss of consciousness 
was achieved, facemask ventilation will be commenced, and anaesthesia will be 
maintained with a volatile anaesthetic agent (age adjusted minimum alveolar 
concentration of 1.0) or using total intravenous technique as decided by the lead 
anaesthetist. Following the confirmation of the onset of neuromuscular blockade 

 
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using neuromuscular monitoring, in an optimal head and neck position, laryngoscopy 
will be performed using the videolaryngoscope as revealed by randomisation. 
Following laryngoscopy, the chosen bougie will be passed through the glottis and 
advanced to the trachea. If there was any hold-up immediately after passing the 
bougie through the vocal cords, it will be gently rotated laterally so that the angle tip 
faced the lateral wall of trachea. Whilst railroading the tube, if there was any 
impingement at the level of arytenoids, the tube will be withdrawn slightly, rotated 
anti-clockwise and then advanced. The correct placement of the tube will be 
confirmed using end tidal CO2. Rest of the anaesthetic management will proceed as 
planned by the lead anaesthetist. 
 
7.4 
Blinding  
Not Applicable. It will not be possible to blind the investigator the type of device used  
7.5 
Emergency unblinding  
Not applicable  
7.6 
Baseline data 
Base line data includes gender, age, weight, height, BMI & ASA score 
Airway assessment includes Mallampati score, thyromental distance, mouth opening, 
jaw protrusion and neck movement. This is the routine assessment undertaken by the 
anaesthetists as a part of standard preoperative airway assessment.  
 
7.7 
Trial assessments 
• Modified intubation difficulty scale score (Appendix 1) 
• Time to successful tracheal intubation: It is time from when the 
videolaryngoscope is introduced into the oral cavity until the first capnography 
waveform is obtained. 
• Laryngoscopy time: It is time from when the videolaryngoscope is introduced 
into the oral cavity to best view of the glottis (vocal cords). 
• First attempt success rate for tracheal intubation 
• Anaesthetist’s visual analogue score for ease of use of the bougie 
 
7.8 
Long term follow-up assessments 

 
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Patients will be reviewed in the first 3 to 24 hours whilst they are in the 
hospital as apart standard postoperative visit. No further follow up is required 
for this study. 
 
7.9 
Storage and analysis of samples 
Not applicable for this study. No biological samples required for this study 
 
7.10 
End of study definition 
 
This is defined as the date on which the last patient (patient number 160) will be 
recruited to the study. 
8. 
STATISTICS AND DATA ANALYSIS 
 
8.1 
Sample size calculation 
From our previous study using CMAC videolaryngoscope and Frova bougie, mean 
mIDS was 1.75 and SD was 0.95 [5]. We considered a 30% reduction in mIDS to be 
clinically relevant. For standardized difference of 0.53, with a power of 0.9 and 
significance level of 0.05, we need 73 patients in each group. To account for failures 
and dropouts, we plan to recruit 160 patients in total.   
 
8.2 
Planned recruitment rate 
We are planning to recruit 160 participants over 18 months. The planned 
recruitment rate is 4 to 5 participants per week.  
Statistical analysis plan 
8.3.1 
 Summary of baseline data and flow of patients 
 
The normally distributed base line data such as age, gender, weight and airway 
assessment parameters between two groups will be compared using students t test. 
Statical significance is taken as p value <0.05. 

 
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CONSORT  Flow Diagram 
Assessed for eligibility (180) 
Excluded  (n=   ) 
   Not meeting inclusion criteria (n=  ) 
   Declined to participate (n=  ) 
   Other reasons (n=  ) 
Analysed  (n=  ) 
 Excluded from analysis (give reasons) (n=  ) 
Lost to follow-up (give reasons) (n=  ) 
Discontinued intervention (give reasons) (n=  ) 
Allocated to Standard bougie (80) 
 Received allocated intervention (n=  ) 
 Did not receive allocated intervention (give 
reasons) (n=  ) 
Lost to follow-up (give reasons) (n=  ) 
Discontinued intervention (give reasons) (n=  ) 
Allocated to Flexitip bougie (80) 
 Received allocated intervention (n=  ) 
 Did not receive allocated intervention (give 
reasons) (n=  ) 
Analysed  (n=  ) 
 Excluded from analysis (give reasons) (n=  ) 
Allocation 
Analysis 
Follow-Up 
Randomized (160) 
Enrollment 
Approximate number 

 
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Flow of participants through the study 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Participant approached; information given  
Consent obtained 
Patient arrived into anaesthetic room 
Monitored, IV access secured  
Randomisation of patients into standard and flexible tip bougie groups 
Pre-oxygenated and GA induced, TOF applied and neuromuscular blockade 
given, absence of twitches on TOF 
Tracheal intubation using non channelled videolaryngoscope with standard 
or flexible tip bougie 
Study end- Rest of the anaesthetic procedure continued as normal 

 
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8.3.2 
Primary outcome analysis 
Primary outcome is modified intubation difficulty scale score (mIDS). Non parametric 
test either Mann-Whitney U test or Kruskal- Wallis test would be used, as 
appropriate.   
 
8.3.3. Secondary outcome analysis 
The sample size is based on primary outcome. 
 
8.4 
Subgroup analyses 
Not applicable 
 
8.5 
Adjusted analysis 
Not applicable  
 
8.6 
Interim analysis and criteria for the premature termination of the trial 
The devices used in this study are currently in clinical use at University 
Hospitals Coventry & Warwickshire NHS Trust. Therefore, no harm is 
anticipated as result of randomizing patients to one or other group. There is 
no plan for interim anlaysis and premature termination.  
 
8.7 
Participant population 
The participant population would include patients scheduled to undergo elective 
surgery under general anaesthesia. The study duration very short, lasting one or two 
minutes. The Base line data is the part of routine airway assessment as a 
preparation for intraoperative tracheal intubation. During the time of tracheal 
intubation, the type of bougie used will be chosen randomly.  The procedure of 
tracheal intubation will be evaluated using modified intubation difficulty scale. 
 
8.8 
Procedure(s) to account for missing or spurious data  
As the study duration is short, we unlikely to miss follow up of patients. All care 
would be take to record all necessary data during preoperative visit and during 

 
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intubation. Very rarely the surgical plan may change, or surgery may be cancelled 
after recruiting. In total we need 146 patients to detect a significant difference in the 
modified intubation difficulty scale score. We have planned to recruit 160 in total to 
overcome any missing data or loss of follow up. 
 
8.9 
Other statistical considerations. 
There is no plan to deviate from original statistics 
  
8.10 Economic evaluation 
  
Not applicable  
 
9. 
DATA MANAGEMENT 
9.1 
Data collection tools and source document identification 
CRFs will be completed at the time of data collection  
No other data collection is required 
 
9.2 
Data handling and record keeping 
Consent forms and CRFs will be filed into the investigator site file and the data is 
then entered at regular interval into the excel sheet on an encrypted NHS computer. 
The site file is securely kept in the locked filing cabinet in the anaesthetic department 
office. 
 
9.3 
Access to Data 
Direct access will be granted to authorised representatives from the Sponsor, host 
institution and the regulatory authorities to permit trial-related monitoring, audits and 
inspections. 
 
9.4 
Archiving 
Research data will be stored off site in a secure approved NHS access facility - TNT. 
Only the research team will have authority to access this data if required via a 
request to the R&D Archiving Team. The study will be archived for 25 years from the 
close of the study with a review 1 year before the anticipated destruction date 
 

 
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10. 
TRIAL OVERSIGHT 
10.1 Role and responsibilities of the Sponsor 
UHCW has agreed to act as sponsor for this trial and will undertake the 
responsibilities of sponsor as defined by the Research Governance Framework and 
ICH Good Clinical Practice. An authorised representative of the Sponsor has 
approved the final version of this protocol with respect to the trial design, conduct, 
data analysis and interpretation and plans for publication and dissemination of 
results. As sponsor, UHCW provides indemnity for this trial and, as such, will be 
responsible for claims for any non-negligent harm suffered by anyone as a result of 
participating in this trial. The indemnity is renewed on an annual basis and will 
continue for the duration of this trial. 
 
10.2 Role and responsibilities of the Funder 
This trial has received a small grant of £1000.00 from Guys Airway Management 
Course-London, towards the R& D support. The design and management of this trial 
are entirely independent of the funder”. 
10.3 Trial Management Arrangements 
10.3.1 
 Trial Steering Committee 
Name 
Affiliation 
Expertise 
Prof Cyprian Mendonca 
Consultant Anaesthetist 
University Hospitals 
Coventry & Warwickshire  
 
International expert in 
difficult airway 
management and co-
author of difficult airway 
society guidelines in 
managing unanticipated 
difficult intubation 
Dr Charles Pairaudeau 
Consultant Anaesthetist 
University Hospitals 
Coventry & Warwickshire 
Consultant anaesthetist 
with special interest in 
difficult airway 
management 
 
The TSC will regularly assess the progress of the study and ensure that the 
investigators will adhere to the protocol.  
10.3.2 
Trial Co-ordinator / Manager 

 
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The Trial coordinator will take the responsibility for overseeing day to day 
coordination of the trial and reporting regularly to the TSC. The Trial coordinator will 
co-ordinate the protocol development, patient and trial management documents, 
setting up and maintaining the Trial Master File, ensure that necessary approvals are 
in place before the start of the trial, ensure that the data security and quality, 
ensuring data protection laws are adhered to and archiving all original trial 
documents including the data forms in line with UHCW NHS Trust policy” 
 
10.3.3 
 Principal Investigators 
Dr Charles Pairadeau is the principal investigator for this study. He will ensure that 
trail is conducted as set out in the protocol  and ensure that the site file contains all 
necessary documents including CVs and delegation log. 
  
11. 
MONITORING, AUDIT & INSPECTION 
The study will be monitored by the Research & Development department at UHCW 
as representatives of the Sponsor, to ensure that the study is being conducted as 
per protocol, adhering to Research Governance and GCP. The approach to, and 
extent of, monitoring will be specified in a trial monitoring plan determined by the risk 
assessment undertaken prior to the start of the study. 
  
12. 
ETHICAL AND REGULATORY CONSIDERATIONS 
12.1 Ethical approval and research governance 
The study will be conducted in compliance the principles of the ICH GCP guidelines 
and in accordance with all applicable regulatory guidance, including, but not limited 
to, the Research Governance Framework. Ethical approval for this study will be 
sought from the Research Ethics Committee combined with Health Research 
Authority (HRA) approval. No study activities will commence until favourable ethical 
opinion and HRA approval has been obtained. Progress reports and a final report at 
the conclusion of the trial will be submitted to the approving REC within the timelines 
defined by the committee. Confirmation of capacity and capability will be obtained 
from the R&D department obtained prior to commencement of the study at all 
participating sites. 

 
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12.2 Peer review 
The study design was initially discussed in anaesthetic departmental research 
meeting and approved by the chair of the department. Subsequently study was peer 
reviewed by Dr Narcis Ungureanu, consultant Anaesthetist, at University Hospitals of 
Birmingham foundation Trust. Dr Narcis Ungureanu has special interest in airway 
management and previously been involved videiolaryngoscopy research. As part of 
small grant application study abstract was submitted to Guy’s airway management 
course grant committee. It was reviewed by Dr Kariem El-Boghdadly, the Editor of 
Anaesthesia Journal.   
 
12.3 Public and Patient Involvement 
The study lay abstract and patient information sheet has been reviewed by the 
Patient and Public Research Advisory group and the documents been revised as per 
their guidance. 
 
12.4 Data protection and patient confidentiality 
The study will comply with the Data Protection Act  2018 and GDPR. Participants will 
be assigned a unique identifier upon enrolment into the study to allow 
pseudonymisation of patient-identifiable of patient-identifiable data. Access to patient 
identifiable data will be restricted to members of the study co-ordination team who 
require it for the performance of their role.  Electronic data will be stored on 
password protected encrypted drives and hard copies of study documents will be 
stored in locked filing cabinets in secure entry-card protected sites. 
 
12.5 Safety reporting 
We are not anticipating any adverse events as a result of study. However, any 
adverse events occurring during the study period will be reported as per the Trust 
policy using Datix.  
 
13. 
DISSEMINATION POLICY 
The study finding will be first presented as an abstract at national meetings and 
subsequently published in Anaesthesia peer reviewed journal. 

 
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14. 
REFERENCES 
 
1. Cook, T. M. et al. (2018) ‘Universal videolaryngoscopy: a structured approach to 
conversion to videolaryngoscopy for all intubations in an anaesthetic and intensive care 
department’, British Journal of Anaesthesia. doi: 10.1016/j.bja.2017.11.014. 
 
2. Frerk CM, Mitchell VS, McNarry AF, et al. Difficult Airway Society 2015 guidelines for the 
management of unanticipated difficult intubation in adults. Br J Anaesth 2015; 115: 827-
48. 
 
3. Levitan, R.M., Heltz, J.W., Sweeney, M., Cooper, R.M. (2011) The Complexities of 
Tracheal Intubation with Direct Laryngoscopy and Alternative Intubation Devices. Annals 
of Emergency Medicine, 57(3): 240-247. 
 
4. Mendonca C, Ungureanu N, Nowicka A, Kumar P. A randomised clinical trial comparing 
the ‘sniffing’ and neutral position using channelled (KingVision) and non-channelled (C-
MAC) videolaryngoscopes. Anaesthesia 2018; 73: 847-855. 
 
5. Kleine-Brueggeney M, Greif R, Schoettker P, Savoldelli GL, Nabecker S, Theiler LG. 
Evaluation of six videolaryngoscopes in 720 patients with a simulated difficult airway: a 
multicentre randomized controlled trial. British Journal of Anaesthesia 2016; 116: 670–9.  
 
6. McElwain J, Malik MA, Harte BH, Flynn NH, Laffey JG. Determination of the optimal 
stylet strategy for the C-MAC" video- laryngoscope. Anaesthesia 2010; 65: 369–78.  
 
7. Evrin, T. et al. (2019) ‘Comparison of Different Intubation Methods in Difficult Airways 
during Simulated Cardiopulmonary Resuscitation with Continuous Chest Compression: A 
Randomized Cross-Over Manikin Trial’, Emergency Medicine International, 
2019(August), pp. 1–7. doi: 10.1155/2019/7306204. 
 
8. Adnet F, Borron SW., Rasine SX., The intubation difficulty scale (IDS): proposal and 
evaluation of a new score characterizing the complexity of endotracheal intubation, 
Anesthesiology. 1997 Dec;87(6):1290-7. 
 
9. Kleine-Brueggeney M, Greif R, Schoettker P, Savoldelli GL, Nabecker S, Theiler LG. 
Evaluation of six videolaryngoscopes in 720 patients with a simulated difficult airway: a 
multicentre randomized controlled trial. British Journal of Anaesthesia 2016; 116: 670–9.  
 
 
 
 
 

 
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APPENDIX 1 
 
Modified difficult intubation scale score  
 
Parameter 
Description 
Score 
Number of attempts>1  
 
 
add 1 point for each additional attempt: N1 
(0 if 1 attempt) 
 
Number of operators>1 
add 1 point for each additional operator: N2 
 
Number of alternative intubation techniques, add 1 point for 
 
 
Bougie impingement: N3 =1 
 
Bougie rotation: N3=2 
 
Subglottic tube impingement: N3=3 
Tube rotation: N3=4 
Other manoeuvre: N3=5 
 
Percentage of Glottis Opening (POGO)   
 
>50%: N4 =0                   <50%: N4=1 
 
Lifting Force Required                  
 
Normal: N5=0                  Increased: N5=1 
 
External Laryngeal Pressure                    Not applied: N6=0           Applied: N6=1 
 
Total Score 
 
 
 
Correlation between mIDS and the Degree of Difficulty 
 
mIDS Score 
Degree of Difficulty 
mIDS =0  
 
mIDS =0 < to < 5  
 
mIDS = >5 
 
mIDS = ∞ 
Easy 
 
Slight difficulty 
 
Moderate to Major Difficulty 
 
Impossible intubation 
 
 
The percentage of glottic opening (POGO) score 
 
 
 
The percentage of glottic opening (POGO) score represents the portion of the glottis 
visualized. It is defined anteriorly by the anterior commissure and posteriorly by the 
interarytenoid notch. The score ranges from 0% when none of the glottis is seen to 100% 
when the entire glottis including the anterior commissure is seen. 
 
 
 

 
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APPENDIX 2 
 
 
 Photograph showing flexible tip bougie  
Video demonstrating flexibility of tip of the flexible tip bougie 
 
 
 
 
 
 
 

 
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