C-MAC Video Stylet vs. Video Endoscope

Study Overview
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Brief Summary
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The purpose of the study is to compare first attempt success rates and time until intubation to establish the learning curves of the participating anaesthesiologists with two different intubation strategies: (Karl Storz C-MAC VS (Video Stylet) and the standard flexible intubation video endoscope at the study site.

Detailed Description
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The intubation of the trachea is a crucial procedure in anaesthesia and emergency medicine, therefore it is considered as one of the core competences in these disciplines. Novices in the field need to learn intubation fast and without harming patients to ensure a patent airway if needed. According to the European Union of Medical Specialists (U.E.M.S., 1050 Brussels, BE), every anaesthesiologist has to master different techniques for the airway management. One is the fiberoptic intubation in awake or asleep patients, to manage a difficult airway. For further training, these core competences need to be extended during the career, from level A (has knowledge) to level D (teaches or supervises others). As the intubation with flexible fiberoptic scopes is the gold standard for the management of a known difficult airway, the investigators want to compare this to a new technique. The use of flexible scopes do not guarantee easy intubation in every difficult airway situation and intubation sometimes is difficult to achieve and requires high proficiency (unability to steer, unability to overcome an anatomical obstacle). Various approaches were introduced by the medical device industry to overcome that problem. One new device is a rigid video stylet with a flexible tip (Karl Storz C-MAC VS), which is an advancement of the older rigid scope Bonfils (Karl Storz). Intubation training with the Bonfils stylet has been shown to require about 20 consecutive tracheal intubations by novices to reach expert time. Learning curves for fiberoptic intubations seem to be similar, but a greater variance was observed. A study of the investigators research-group (unpublished data, KEK 247/09), comparing learning curves between the rigid fiberoptic Bonfils and the semi-rigid fiberoptic SensaScope suggested a 90% success rate for intubation within 60 seconds after about 15 trials (Bonfils) and 20 trials (SensaScope). In comparison, there is no validated data for the use of rigid scopes with flexible tips, as these tool are very new. Video stylets are tools originally designed for difficult airway management as well. The C-MAC VS combines rigid and semi-rigid abilities. Intubation seems to become very easy. But yet, there is no data available which proves that assumption. Thus the study wants to evaluate if intubation success and time is superior with the C-MAC Video Scope compared to the difficult intubation gold standard, the intubation with a standard flexible fiberoptic scope.

Official Title
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Is a Rigid Fiberscope With a Flexible Tip Superior to Standard Flexible Fiberoptic Intubation: a Prospective Multicentre Randomised Controlled Trial

Conditions
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Intubation

Intervention / Treatment
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* Device: C- MAC VS
* Device: Video Endoscope


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Anaesthesiologists starting in the respective anaesthesia department who are not experienced with tracheal intubation with the study devices Informed Consent as documented by signature (Appendix Informed Consent Form) Novice to the C-MAC VS No/few fiberoptic oral asleep intubation experience (max. 5x during the last year) Exclusion Criteria: More than 5 uses during the past year of either one of the study devices Not available at the study site during entire study (expected drop outs) Not able to fill out English case reports Patients: Planned delayed extubation (e.g. planned transfer to ICU)
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: C- MAC VS<br>Intubation with C- MAC VS | Device: C- MAC VS<br>* The C-MAC VS is a new device on the airway management aid market. It will be used according to the instructions of the distributor. Before the study starts on humans, each study participants will do at least 5 intubations on an airway manikin or more until he or she feels confident to use the device.<br>|
| Active Comparator: Video Endoscope<br>Intubation with standard fiberoptic scope | Device: Video Endoscope<br>* Fiberoptic video endoscopic devices are standard aids to facilitate intubation on all study sites and are used according to the instructions to use. To facilitate fiberoptic intubation a macintosh blade to raise the root of tongue will be used. Also with these devices the study participants need at least 5 trials to intubate a manikin (or more to feel confident) before they are going to use the study device in patients.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time (seconds) to successful orotracheal intubation during the first successful attempt. | With the C-MAC VS and the standard flexible scope | Start: Device passes patients lips; End: Device is completely removed out of the tracheal tube (a trial consists of a maximum of 2 intubation attempts, each with a maximum duration of 120 seconds) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Overall time from startpoint to glottic view | The overall time is defined as the total time to glottic view, summarized over all attempts. | It cannot be longer than 240 seconds and is defined for unsuccessful trials, i.e. if no intubation was established, as 360 seconds. | 
| Time to first end expiratory CO2 reading | After the airway is secured the first end expiratory CO2 is shown.The investigators will use the standard non-invasive monitoring of the University Hospital to measure the end expiratory CO2 | Start: Device passes patients lips; End: First end expiratory CO2 reading (trial in total not >240 seconds) | 
| Number of intubation attempts | End of an attempt defined as: device has to be completely removed out of the patient's airway. | Start: Device passes patients lips; End: Device is completely removed out of the tracheal tube (trial in total not >240 seconds) | 
| Subjective difficulty of the intubation procedure | The VAS- Visual analogue scale (score 1-10) is used. It is a measurement instrument for subjective characteristics that cannot be directly measured. Therefore numbers are used to evaluate. | Start: Device passes patients lips; End: Device is completely removed out of the tracheal tube (trial in total not >240 seconds | 
| Cormack/Lehane grade | The Cormack/Lehane grade is used to describe the laryngeal view during laryngoscopy. It is rated by the supervisor. | Start: Device passes patients lips; End: Device is completely removed out of the tracheal tube (trial in total not >240 seconds) | 
| Limited or restricted vision through the devices (either C MAC VS or a standard flexible scope) | The view can be clear or blurred. | Start: Device passes patients lips; End: Device is completely removed out of the tracheal tube (trial in total not >240 seconds) | 
| Correlation to patients' anatomical characteristics | To assess the influence of difficulty with the airway | Start: Device passes patients lips; End: Device is completely removed out of the tracheal tube (trial in total not >240 seconds) | 
| Patients vital parameter such as heart rate, during the intubation attempt | The investigators will use the standard non-invasive monitoring of the University Hospital to measure the heart rate. | Start: Device passes patients lips; End: Device is completely removed out of the tracheal tube (trial in total not >240 seconds) | 
| Patients vital parameter such as blood pressure, during the intubation attempt | The investigators will use the standard non-invasive monitoring of the University Hospital to measure the blood pressure (in millimeters of mercury) | Start: Device passes patients lips; End: Device is completely removed out of the tracheal tube (trial in total not >240 seconds) | 
| Patients vital parameter such as oxygen saturation, during the intubation attempt | The investigators will use the standard non-invasive monitoring of the University Hospital to measure the oxygen saturation (SpO2 in percent). | Start: Device passes patients lips; End: Device is completely removed out of the tracheal tube (trial in total not >240 seconds) | 
| Participants characteristics and demographic data | Basic demographic data (including years of experience in anaesthesia). | Before the study session starts (up to 24 hours before the first intubation attempt) | 
| Patients demographic data such as height | The size of each patient will be presented in meter/centimeter | During the process of screening, up to 24 hours before the study session starts | 
| Patients demographic data such as weight | The weight of each patient will be presented in kilograms | During the process of screening, up to 24 hours before the study session starts | 
| Patients demographic data such as ASA risc classification (ASA= American Society of Anaesthesiologists) | The ASA grading system is used to evaluate the degree of a patient's physical state before selecting the anesthetic or before performing surgery. | During the process of screening, up to 24 hours before the study session starts | 
| Patients demographic data such as age | The age of each patient will be presented in years. | During the process of screening, up to 24 hours before the study session starts | 
| Patients demographic data such as gender | The gender of each patient will be presented in female or male. | During the process of screening, up to 24 hours before the study session starts |