[Out-of-hospital airway management in trauma patients : Experiences with the C-MAC® video laryngoscope]

Comparison of first-pass intubation success rates between two different videolaryngoscopes in an Australian prehospital and retrieval medicine service

OBJECTIVE

To determine the effectiveness of the GlideScope Go videolaryngoscope (VL) in tracheal intubation in an Australian physician-staffed critical care prehospital and retrieval medicine service.

METHODS

Our service has used VLs for several years, including the McGrath Mac, and from February 2019 the GlideScope Go. Clinicians may alternatively use direct laryngoscopy with a Macintosh laryngoscope. We conducted a non-inferiority trial comparing first-pass intubation success using the GlideScope Go VL with that using the McGrath Mac VL. We collected data on video intubation of all adult patients between February 2017 and December 2019, by our service. Comparison was also made with patients intubated using direct laryngoscopy with a Macintosh direct laryngoscope.

RESULTS

One hundred and seventy-two patients were intubated with the aid of a VL. First-pass success rates (95% confidence interval [CI]) were 0.98 (0.92-0.99) and 0.92 (0.84-0.96), respectively, for the GlideScope Go and McGrath Mac, giving a difference (95% CI) in first-pass success rates of 0.06 (-0.01 to 0.13). First-pass success rate for the Macintosh laryngoscope was 0.88 (0.84-0.91).

CONCLUSIONS

We demonstrated that first-pass success rates with the GlideScope Go are at least as good as our service had achieved with both the McGrath Mac and with direct laryngoscopy.

Using a Bougie With C-MAC Video Laryngoscopy Did Not Improve First-Attempt Intubation Success Rates in Critical Care Air Transport

OBJECTIVE

Studies have shown a bougie improves first-attempt success rates when used in combination with direct laryngoscopy during the initial attempt. The purpose of this study was to determine whether the use of a bougie in combination with C-MAC (Karl Storz, Tuttlingen, Germany) improves first-attempt success rates of endotracheal intubation (ETI) compared with C-MAC with a traditional stylet.

METHODS

This study is a retrospective chart review using data collected on 371 intubations completed by a single air medical service using the C-MAC laryngoscope and either a bougie or a stylet.

RESULTS

The overall success rate using C-MAC for ETI with either a bougie or a stylet was 83%. There was no statistically significant difference between first-attempt successful intubations using C-MAC and a bougie (82%) or a stylet (86%) (χ1 = 0.871, P = .351). There was no statistically significant difference between laryngoscopy grade and the number of attempts that resulted in a successful intubation (χ1 = 0.743, P = .7).

CONCLUSION

There was no difference between first-attempt success rates using video laryngoscopy with a bougie, overall intubation success rates, or difficult intubation success rates compared with video laryngoscopy with a stylet, indicating that the purpose of a bougie as a rescue device did not hold true in the prehospital setting of our critical care air medical service.

Video screen visualization patterns when using a video laryngoscope for tracheal intubation: A systematic review

OBJECTIVE

Published studies of video laryngoscopes are often limited by the lack of a clear definition of video laryngoscopy (VL). We performed a systematic review to determine how often published studies of VL report on video screen visualization.

METHODS

We searched PubMed, EMBASE and Scopus for interventional and observational studies in which a video laryngoscope equipped with a standard geometry blade was used for tracheal intubation. We excluded simulation based studies. Our primary outcome was data on video laryngoscope screen visualization. Secondary outcomes were explicit methodology for screen visualization.

RESULTS

We screened 4838 unique studies and included 207 (120 interventional and 87 observational). Only 21 studies (10% of 207) included any data on video screen visualization by the proceduralist, 19 in a yes/no fashion only (ie, screened viewed or not) and 2 with detail beyond whether the screen was viewed or not. In 11 more studies, visualization patterns could be inferred based on screen availability and in 16 more studies, the methods section stated how screen visualization was expected to be performed without reporting data collection on how the proceduralist interacted with the video screen. Risk of bias was high in the majority of included studies.

CONCLUSIONS

Published studies of VL, including many clinical trials, rarely include data on video screen visualization. Given the nuances of using a video laryngoscope, this is a critical deficiency, which largely prevents us from knowing the treatment effect of using a video laryngoscope in clinical practice. Future studies of VL must address this deficiency.

Analysis of tracheal intubation in out-of-hospital helicopter emergency medicine recorded by video laryngoscopy

Background

Tracheal intubation remains the gold standard of airway management in emergency medicine and maximizing safety, intubation success, and especially first-pass intubation success (FPS) in these situations is imperative.

Methods

We conducted a prospective observational study on all 12 helicopter emergency medical service (HEMS) bases of the Swiss Air Rescue, between February 15, 2018, and February 14, 2019. All 428 patients on whom out-of-hospital advanced airway management was performed by the HEMS crew were included. The C-MAC video laryngoscope was used as the primary device for tracheal intubation. Intubation procedures were recorded by the video laryngoscope and precise time points were recorded to verify the time necessary for each attempt and the overall procedure time until successful intubation. The videos were further analysed for problems and complications during airway management by an independent reviewer. Additionally, a questionnaire about the intubation procedure, basic characteristics of the patient, circumstances, environmental factors, and the provider’s level of experience in airway management was filled out. Main outcome measures were FPS of tracheal intubation, overall success rate, overall intubation time, problems and complications of video laryngoscopy.

Results

FPS rate was 87.6% and overall success rate 98.6%. Success rates, overall time to intubation, and subjective difficulty were not associated to the providers’ expertise in airway management. In patients undergoing CPR FPS was 84.8%, in trauma patients 86.4% and in non-trauma patients 93.3%. FPS in patients with difficult airway characteristics, facial trauma/burns or obesity ranges between 87 and 89%. Performing airway management indoors or inside an ambulance resulted in a significantly higher FPS of 91.1% compared to outdoor locations (p < 0.001). Direct solar irradiation on the screen, fogging of the lens, and blood on the camera significantly impaired FPS. Several issues for further improvements in the use of video laryngoscopy in the out-of-hospital setting and for quality control in airway management were identified.

Conclusion

Airway management using the C-MAC video laryngoscope with Macintosh blade in a group of operators with mixed experience showed high FPS and overall rates of intubation success. Video recording emergency intubations may improve education and quality control.