C-MAC VS Clinical Observation

The Rigid Fiberscope With a Flexible Tip C-MAC®VS in the Real Anaesthesia World: A Clinical Observation of Intubation Success and Complications

During orotracheal intubation failure in securing an airway can result in serious oxygenation problems.

Beside the classic laryngoscopes and fibreoptic scopes, devices with high-resolution video cameras placed in the tip of the devices, were developed and attained in daily routines. Studies and case reports reveal them to be superior in both normal and difficult intubation, especially improving the first-attempt success rate.

Latest advancements of the Bonfils fiberscope resulted in the C-MAC VS, which combines rigid and semi-rigid abilities to a rigid video stylet with a flexible tip. Because of its front positioned high-resolution camera resulting in an indirect visualization, it may also have the benefits of video laryngoscopes.

Very little data is available on larger numbers of use and the investigators do not know about rare side effects and complications with the use of the device, such as esophageal intubations. Due to its direct view and positioning on vocal cord level, the investigators expect a similar or even lower rate of endotracheal intubation, using the C-MAC VS.

The investigators therefore plan to analyze the use of the C-MAC VS regarding its efficiency and safety during airway management in everyday clinical practice. This should provide the evidence about safe use, possible risk factors, rare complications and adverse events, as well as the preferred clinical airway situations to use the C-MAC VS.

Study Overview

• Status: Terminated
• Conditions: Intubation Complication
• Intervention / Treatment: Device: C- MAC VS

Detailed Description

Orotracheal intubation is a core competence in anesthesia and emergency medicine. Failure in securing an airway can result in hypoxemia, aspiration, neurologic damage, cardiovascular complications, and death. Difficult anatomic structures, upper airway abnormalities, or airway trauma bear the risk of failed intubation inability to ventilate the lungs that furthermore results in oxygenation failure.

Literature tells that the rate of unexpected difficult intubations ranges from 5 to 10%, mostly corresponding to a Cormack/Lehane grade (C&L) 3 or 4.

Beside the classic laryngoscopes and fibreoptic scopes, devices with high-resolution video cameras placed in the tip of the devices, were developed and attained in daily routines. Studies and case reports reveal them to be superior in both normal and difficult intubation, especially improving the first-attempt success rate.

Rigid fiber-optic scopes may reduce intubation time and their use may result in a higher success rate. A study with 216 Patients using the Bonfils fiberscope for airway management, showed a success rate up to 98,4. Looking at the complication rates, upper airway trauma in normal patients after direct laryngoscopy with a Macintosh blade has been reported up to 6.9% and can be reduced by using a video laryngoscope.

Latest advancements of the Bonfils fiberscope resulted in the C-MAC VS, which combines rigid and semi-rigid abilities to a rigid video stylet with a flexible tip. Because of its front positioned high-resolution camera resulting in an indirect visualization, it may also have the benefits of video laryngoscopes.

But data about this new tool is rare, because this device is recently licensed. Very little data is available on larger numbers of use and the investigators do not know about rare side effects and complications with the use of the device, such as esophageal intubations.

Due to its direct view and positioning on vocal cord level, the investigators expect a similar or even lower rate of endotracheal intubation using the C-MAC VS.

The investigators therefore plan to analyze the use of the C-MAC VS regarding its efficiency and safety during airway management in everyday clinical practice. This prospective observational trial should provide the evidence about safe use, possible risk factors, rare complications and adverse events, as well as the preferred clinical airway situations to use the C-MAC VS.

The investigators will check for given general research consent. All airway management procedures and the recorded data are daily clinical routine. No experimental intervention will take place, there is no change in usual clinical practice and therefore patient's safety will not be altered by participating in the study.

The study will end when the tracheal tube is placed properly and the airway is secured. On the day after surgery the investigators will visit the patient as usually after each anesthesia to obtain follow up data. In case of a complication the patient will be followed up until the problem is cured or solved.

• Study Type: Observational
• Enrollment (Actual): 10

Contacts and Locations

Study Locations

• Switzerland
  • Bern, Switzerland, 3011
    • Bern University Hospital and University of Bern

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Adult patients undergoing general anaesthesia for elective procedures at the Bern University Hospital will be screened using the Anesthesia Information System (AIS). Patients that meet the inclusion criteria, we will visited to confirm that and the given general consent.

Description

Inclusion Criteria:

• Patients for elective and emergency surgery who have at least one predictor for difficult airway management, which are: Mallampati score >2, mouth opening <4cm, thyromental distance <6cm, head & neck movements <90°, short neck, reduced reclination.
• Patients who signed general research consent in Switzerland.

Exclusion Criteria:

• Patients under the age of 18 years
• Personnel at the study site not available of not sufficient ted in the device.
• Expected impossible mask ventilation
• High risk of aspiration (requiring rapid sequence induction intubation)
• Intracranial surgery
• Limited knowledge of German language or refusing general consent.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
First-attempt oro-tracheal intubation success rate in percentage	Rate of a successful intubation at first attempt	The overall rate of successful intubation at first attempt. The study will end when the tracheal tube is placed properly and the airway is secured (the first attempt should not pass 120 seconds)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall success rate	The overall rate of successful intubation.	Intraoperative (The study will end when the tracheal tube is placed properly and the airway is secured.)
Number of attempts	The total number of attempts needed for the intubation in each study session	Intraoperative (Starts when the device is inserted in the patients mouth and ends when the airway is secured.)
Difficulty of intubation	It can range from very easy to very difficult	Starts when the device is inserted in the patients mouth and ends when the airway is secured. Estimated time: 120 seconds
Preferred method used to lift the tongue ventral to increase space in the oral cavity and the approach	The method can include using finger, laryngoscope, spatula or other. A medial, retromolar right side and retromolar left side approach can be performed.	The beginning of the intubation procedure, when the device is inserted in the patients mouth. Estimated time 120 seconds
Tube size used	Variations of tube sizes that will be used. It is chosen because of the patients size.	Baseline
Time of the intubation procedure	The procedure starts as soon as the tip of the device passes patients lips and ends when a first recording of the endtidal carbon dioxide is shown.	Starts when the device is inserted in the patients mouth and ends when the airway is secured. Estimated time: 120 seconds
Intubation interim times	Interim times until the device is completely out of tube	The interim times need to be as short as possible. The estimated time for intubation: 120 seconds.
An alternative method to establish a patent airway	If intubation is not possible with the Intubations Device C-MAC® VS Video Stylet ,a different device has to be used for intubation. Alternative device: flexible laryngoscope,C-MAC Videolaryngoskop,Macintosh or LAMA.	Starts when the device is inserted in the patients mouth and ends when the airway is secured. Estimated time for intubation: 120 seconds
Possible problems with C-MAC VS	Adverse Events, technical problems with the device	If any problems occur during the preparations or during intubation itself which starts when the device is inserted in the patients mouth and ends when the airway is secured. Estimated time for intubation: 120 seconds
Complications during intubation	For example bleeding, laryngospasm, edema, swelling and other can be complications during intubation.	Starts when the device is inserted in the patients mouth and ends when the airway is secured. Estimated time: 120 seconds
Airway ratings (Cormack- Lehane and POGO)	Cormack- and Lehane is used to classify the laryngeal view, POGO stands for percentage of glottic opening	The ratings are made during the process of intubation, so when the the device is inserted in the patients mouth and ends when the airway is secured. Estimated time for intubation: 120 seconds

Collaborators and Investigators

• Sponsor: University Hospital Inselspital, Berne
• Investigators: Principal Investigator: Robert Greif, Prof., MD, Department of Anaesthesiology and Pain Therapy, Bern University Hospital

Publications and helpful links

General Publications

• Choi JW, Kim JA, Jung HJ, Kim WH. Tracheal Intubation with a McGrath(R) Series 5 Video Laryngoscope by Novice Personnel in a Cervical-immobilized Manikin. J Emerg Med. 2016 Jan;50(1):61-6. doi: 10.1016/j.jemermed.2015.06.079. Epub 2015 Oct 1.
• Mort TC. Emergency tracheal intubation: complications associated with repeated laryngoscopic attempts. Anesth Analg. 2004 Aug;99(2):607-13, table of contents. doi: 10.1213/01.ANE.0000122825.04923.15.
• Peterson GN, Domino KB, Caplan RA, Posner KL, Lee LA, Cheney FW. Management of the difficult airway: a closed claims analysis. Anesthesiology. 2005 Jul;103(1):33-9. doi: 10.1097/00000542-200507000-00009.
• Williams KN, Carli F, Cormack RS. Unexpected, difficult laryngoscopy: a prospective survey in routine general surgery. Br J Anaesth. 1991 Jan;66(1):38-44. doi: 10.1093/bja/66.1.38.
• Maassen R, Lee R, van Zundert A, Cooper R. The videolaryngoscope is less traumatic than the classic laryngoscope for a difficult airway in an obese patient. J Anesth. 2009;23(3):445-8. doi: 10.1007/s00540-009-0780-1. Epub 2009 Aug 14.
• Burdett E, Ross-Anderson DJ, Makepeace J, Bassett PA, Clarke SG, Mitchell V. Randomized controlled trial of the A.P. Advance, McGrath, and Macintosh laryngoscopes in normal and difficult intubation scenarios: a manikin study. Br J Anaesth. 2011 Dec;107(6):983-8. doi: 10.1093/bja/aer295. Epub 2011 Sep 22.
• Kory P, Guevarra K, Mathew JP, Hegde A, Mayo PH. The impact of video laryngoscopy use during urgent endotracheal intubation in the critically ill. Anesth Analg. 2013 Jul;117(1):144-9. doi: 10.1213/ANE.0b013e3182917f2a. Epub 2013 May 17.

Study record dates

Study Major Dates

• Study Start (ACTUAL): March 1, 2019
• Primary Completion (ACTUAL): December 30, 2021
• Study Completion (ACTUAL): December 30, 2021

Study Registration Dates

• First Submitted: November 9, 2018
• First Submitted That Met QC Criteria: February 26, 2019
• First Posted (ACTUAL): February 27, 2019

Study Record Updates

• Last Update Posted (ACTUAL): June 2, 2022
• Last Update Submitted That Met QC Criteria: May 29, 2022
• Last Verified: May 1, 2022

More Information

Terms related to this study

• Other Study ID Numbers: 2018-01452

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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