C-MAC Video Stylet vs. Video Endoscope

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

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.

Study Overview

• Status: Recruiting
• Conditions: Intubation
• Intervention / Treatment: Device: C- MAC VS; Device: Video Endoscope

Detailed Description

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 A study of the investigators research-group (unpublished data, KEK 247/09), comparing learning curves between the rigid fiberoptic Bonfils and the semi-rigid fiberoptic SensaScope suggested a 90% success rate for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.

• Study Type: Interventional
• Enrollment (Anticipated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Robert Greif, Prof., M.D.; Phone Number: + 41-31-632-1629; Email: Robert.Greif@insel.ch
• Study Contact Backup: Name: Lorenz Theiler, Prof., M.D; Phone Number: + 41-31-632-0804; Email: lorenz.theiler@insel.ch

Study Locations

• Canada
  • Ontario
    • London, Ontario, Canada
      • Not yet recruiting
      • LHSC / St. Joesephs
      • Contact: Rüdiger Noppens, MD, PHD
• Spain
  • Zaragoza, Spain
    • Not yet recruiting
    • Miguel Servet University Hospital
    • Contact: Guillermo I. Perez Navarro, MD, PHD
• Switzerland
  • Bern, Switzerland, 3010
    • Recruiting
    • Inselspital, Bern University Hospital
    • Contact: Robert Greif, Prof., MD; Phone Number: 0041316322111; Email: robert.greif@insel.ch
    • Contact: Lorenz G Theiler, Prof., MD; Phone Number: 0041316322111; Email: loren.theiler@insel.ch

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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)

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: C- MAC VS; Intubation with C- MAC VS	Device: C- MAC VS; 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.
Active Comparator: Video Endoscope; Intubation with standard fiberoptic scope	Device: Video Endoscope; 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.

What is the study measuring?

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

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of injuries due to intubation attempts	Dental damage, mucosal damage, hoarseness, sore throat, swallowing disorders	Follow-Up on the first post anaesthesia day (maximum 24 hours post anaesthesia)
How often a "hand over to specialist" happens	The device has to be handed over to the supervisor	Start: Device passes patients lips; End: Device is completely removed out of the tracheal tube (trial in total not >240 seconds)

Collaborators and Investigators

• Sponsor: University Hospital Inselspital, Berne
• Investigators: Principal Investigator: Lorenz Theiler, Prof., M.D, Department of Anaesthesiology and Pain Therapy

Publications and helpful links

General Publications

• Sakles JC, Chiu S, Mosier J, Walker C, Stolz U. The importance of first pass success when performing orotracheal intubation in the emergency department. Acad Emerg Med. 2013 Jan;20(1):71-8. doi: 10.1111/acem.12055.
• Kleine-Brueggeney M, Greif R, Urwyler N, Wirthmuller B, Theiler L. The performance of rigid scopes for tracheal intubation: a randomised, controlled trial in patients with a simulated difficult airway. Anaesthesia. 2016 Dec;71(12):1456-1463. doi: 10.1111/anae.13626. Epub 2016 Sep 27.
• Halligan M, Charters P. A clinical evaluation of the Bonfils Intubation Fibrescope. Anaesthesia. 2003 Nov;58(11):1087-91. doi: 10.1046/j.1365-2044.2003.03407.x.
• Isono S, Greif R, Mort TC. Airway research: the current status and future directions. Anaesthesia. 2011 Dec;66 Suppl 2:3-10. doi: 10.1111/j.1365-2044.2011.06928.x.
• Levitan RM, Goldman TS, Bryan DA, Shofer F, Herlich A. Training with video imaging improves the initial intubation success rates of paramedic trainees in an operating room setting. Ann Emerg Med. 2001 Jan;37(1):46-50. doi: 10.1067/mem.2001.111516.
• Dalal PG, Dalal GB, Pott L, Bezinover D, Prozesky J, Bosseau Murray W. Learning curves of novice anesthesiology residents performing simulated fibreoptic upper airway endoscopy. Can J Anaesth. 2011 Sep;58(9):802-9. doi: 10.1007/s12630-011-9542-2. Epub 2011 Jun 28.
• Smith JE, Jackson AP, Hurdley J, Clifton PJ. Learning curves for fibreoptic nasotracheal intubation when using the endoscopic video camera. Anaesthesia. 1997 Feb;52(2):101-6. doi: 10.1111/j.1365-2044.1997.23-az023.x.

Study record dates

Study Major Dates

• Study Start (Actual): December 15, 2018
• Primary Completion (Anticipated): December 31, 2023
• Study Completion (Anticipated): December 31, 2023

Study Registration Dates

• First Submitted: November 8, 2018
• First Submitted That Met QC Criteria: November 20, 2018
• First Posted (Actual): November 21, 2018

Study Record Updates

• Last Update Posted (Estimate): December 7, 2022
• Last Update Submitted That Met QC Criteria: December 6, 2022
• Last Verified: December 1, 2022

More Information

Terms related to this study

• Other Study ID Numbers: 2018-00629

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No