Comparing the first-attempt tracheal intubation success of the hyperangulated McGrath® X-blade vs the Macintosh-type CMAC videolaryngoscope in patients with cervical immobilization: a two-centre randomized controlled trial

A novel technique of handling the blade for videolaryngoscopy intubation in patients with a semi-rigid neck collar: a prospective randomized controlled trial

BACKGROUND

Semi-rigid neck collars to protect the cervical spine can limit the extent of neck movement and mouth opening; this may further complicate orotracheal intubation. We aimed to compare intubation environments obtained with videolaryngoscopy using the technique of gliding a blade under the epiglottis and that obtained using the conventional Macintosh blade technique of blade tip placement on the vallecula.

METHODS

This prospective randomized study included patients aged ≥ 20 years with American Society of Anesthesiologists physical status I-III scheduled for cervical spine surgery between October 2020 and August 2021. Patients were divided into two groups according to the placement of the blade of the McGrathTM videolaryngoscope: the gliding and conventional groups. The percentage of glottic opening (POGO) score was the primary endpoint. We also recorded the time to obtain the optimal laryngoscopic view, intubation duration, and ease and satisfaction of the researcher performing intubation.

RESULTS

Among 176 patients, the POGO scores were significantly higher in the gliding group than in the conventional group (88.9 ± 14.7 vs. 63.8 ± 27.4, P < 0.001). The time to achieve the optimal glottic view for intubation and duration of intubation were also shorter, and ease and satisfaction in performing intubation were better in the gliding group than in the conventional group.

CONCLUSION

Our findings demonstrated a superior glottic view and more favorable intubation environments when the blade tip was placed under the epiglottis than using the conventional Macintosh technique in patients with immobilized cervical spine.

Clinically Preferred Videolaryngoscopes in Airway Management: An Updated Systematic Review

Videolaryngoscopes (VLs) have emerged as a safety net offering several advantages over direct laryngoscopy (DL). The aim of this study is to expand on our previous study conducted in 2016, to deduce which VL is most preferred by clinicians and to highlight any changes that may have occurred over the past 7 years. An extensive systematic literature review was performed on Medline, Embase, Web of Science, and Cochrane Central Database of Controlled Studies for articles published between September 2016 and January 2023. This review highlighted similar results to our study in 2016, with the CMAC being the most preferred for non-channelled laryngoscopes, closely followed by the GlideScope. For channelled videolaryngoscopes, the Pentax AWS was the most clinically preferred. This review also highlighted that there are minimal studies that compare the most-used VLs, and thus we suggest that future studies directly compare the most-used and -preferred VLs as well as the specific nature of blades to attain more useful results.

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.

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.