Efficacy of Video Laryngoscopy versus Direct Laryngoscopy in the Prehospital Setting: A Systematic Review and Meta-Analysis

Video laryngoscopy versus direct laryngoscopy in achieving successful emergency endotracheal intubations: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Intubating a patient in an emergent setting presents significant challenges compared to planned intubation in an operating room. This study aims to compare video laryngoscopy versus direct laryngoscopy in achieving successful endotracheal intubation on the first attempt in emergency intubations, irrespective of the clinical setting.

METHODS

We systematically searched PubMed, Scopus, Web of Science, and the Cochrane Central Register of Controlled Trials from inception until 27 February 2023. We included only randomized controlled trials that included patients who had undergone emergent endotracheal intubation for any indication, regardless of the clinical setting. We used the Cochrane risk-of-bias assessment tool 2 (ROB2) to assess the included studies. We used the mean difference (MD) and risk ratio (RR), with the corresponding 95% confidence interval (CI), to pool the continuous and dichotomous variables, respectively.

RESULTS

Fourteen studies were included with a total of 2470 patients. The overall analysis favored video laryngoscopy over direct laryngoscopy in first-attempt success rate (RR = 1.09, 95% CI [1.02, 1.18], P = 0.02), first-attempt intubation time (MD =  - 6.92, 95% CI [- 12.86, - 0.99], P = 0.02), intubation difficulty score (MD =  - 0.62, 95% CI [- 0.86, - 0.37], P < 0.001), peri-intubation percentage of glottis opening (MD = 24.91, 95% CI [11.18, 38.64], P < 0.001), upper airway injuries (RR = 0.15, 95% CI [0.04, 0.56], P = 0.005), and esophageal intubation (RR = 0.37, 95% CI [0.15, 0.94], P = 0.04). However, no difference between the two groups was found regarding the overall intubation success rate (P > 0.05).

CONCLUSION

In emergency intubations, video laryngoscopy is preferred to direct laryngoscopy in achieving successful intubation on the first attempt and was associated with a lower incidence of complications.

Comparison of UESCOPE VL 400, I-View, Non-Channeled Airtraq Videolaryngoscopes and Macintosh Laryngoscope for Tracheal Intubation in Simulated Out-of-Hospital Conditions: A Randomized Crossover Manikin Study

The aim of the study was to test the hypothesis that the results obtained with three different types of video laryngoscopes (UESCOPE VL-400, I-View, Non-Channeled Aitraq) with and without an endotracheal stylet should be better than the results obtained with a Macintosh laryngoscope in a simulated out-of-hospital scenario by a person without clinical experience. Primary outcome measures were the time taken to successfully achieve tracheal intubation (TI). Secondary outcomes included the grade of glottic view (Cormack and Lehane grades 1-4), the incidence of successful TI, the number of audible dental clicks indicating potential dental damage, the level of effort required to perform TI, and the operator's comfort during the procedure. The time required to achieve tracheal intubation successfully was significantly longer with the Macintosh laryngoscope and Airtraq than with the other video laryngoscopes. The use of the stylet significantly reduced the time required for tracheal intubation with the Macintosh laryngoscope (21.8 sec. vs. 24.0 sec., p = 0.026), UESCOPE VL 400 (18.1 sec. vs. 23.4 sec., p = 0.013), and Airtraq (22.7 sec. vs. 34.5 sec., p < 0.001). There were no significant differences in intubation time when using the I-View with or without stylets. No differences were observed in the Cormack-Lehane grading. The success rate of intubation was 100% for the Macintosh and I-View laryngoscopes used with or without stylets and for the UESCOPE VL 400 and Airtraq laryngoscopes used with stylets. Without stylets, the success rate of intubation was 96.6% for the UESCOPE VL 400 and 86.6% for the Airtraq. There were no significant differences in the risk of dental damage between the Macintosh, UESCOPE VL 400, I-View, and Airtraq laryngoscopes, regardless of the use of stylets (without and with stylets). The use of stylets significantly reduced dental damage only for the Airtraq laryngoscope: 8 (26.6%) vs. 2 (6.6%). Statistically significant differences in perceived exertion were observed between the mentioned laryngoscopes, both with and without stylets. However, there were no differences in the comfort of use between the laryngoscopes, regardless of the use of stylets (without and with stylets. The use of stylets led to better comfort in the case of the Macintosh (2.5 vs. 3, p = 0.043) and UESCOPE VL 400 (2 vs. 3, p = 0.008) laryngoscopes. In our study, the I-View and UESCOPE VL-400 video laryngoscopes provided better intubation results than the Macintosh laryngoscope in terms of time needed to intubate, glottis visibility, and reduction in dental damage. The use of the stylet did not significantly improve the intubation results compared to the results obtained in direct laryngoscopy. Due to the small study group and the manikin model, additional studies should be performed on a larger study group.

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 Laryngoscopy versus Direct Laryngoscopy for Orotracheal Intubation in the Out-of-Hospital Environment: A Systematic Review and Meta-Analysis

OBJECTIVE

To determine the effect of video and direct laryngoscopy on first-pass success rates for out-of-hospital orotracheal intubation.

METHODS

MEDLINE, Embase, and Cochrane databases were searched from inception to January 2023. Out-of-hospital studies comparing video and direct laryngoscopy on either first-pass or overall intubation success were included. A random effects meta-analysis was performed with a primary outcome of first-pass success stratified by clinician type and laryngoscope blade geometry. The secondary outcomes were overall intubation success stratified by clinician type, and intubation time. All hypotheses and subgroup analyses were determined a priori.

RESULTS

Twenty-five studies involving 35,489 intubations met inclusion criteria. Substantial heterogeneity (>75%) precluded reporting point estimates for nearly all analyses. For our primary outcome, video laryngoscopy was associated with improved first-pass success in 3/5 physician studies, 4/6 critical care paramedic/registered nurse studies, and 7/10 paramedic studies. Video laryngoscope devices with Macintosh blade geometry were associated with improved first-pass success in 7/10 studies, while devices with hyperangulated geometry were associated with improved first-pass success in 3/7 studies. Overall intubation success was greater with video laryngoscopy in 2/6 studies in the physician subgroup and 9/10 studies in the paramedic subgroup. Video laryngoscopy was not associated with overall intubation success among critical care paramedics/nurses (OR = 1.89, 0.96 to 3.72, I2 = 34%). Lastly, 4/5 studies found video laryngoscopy to be associated with longer intubation times.

CONCLUSIONS

We found substantial heterogeneity among out-of-hospital studies comparing video laryngoscopy to direct laryngoscopy on first-pass success, overall success, or intubation time. This heterogeneity was not explained with stratification by study design, clinician type, video laryngoscope blade geometry, or leave-one-out meta-analysis. A majority of studies showed that video laryngoscopy was associated with improved first pass success in all subgroups, but only for paramedics and not physicians when looking at overall success. This improvement was more common in studies that used Macintosh blades than those that used hyperangulated blades. Future research should explore the heterogeneity identified in our analysis with an emphasis on differences in training, clinical milieu, and specific video laryngoscope devices.