Hyperangulated vs. Macintosh videolaryngoscopy in adults with anticipated difficult airway management: a randomised controlled trial.

BACKGROUND: It is not certain whether the blade geometry of videolaryngoscopes, either a hyperangulated or Macintosh shape, affects glottic view, success rate and/or tracheal intubation time in patients with expected difficult airways. We hypothesised that using a hyperangulated videolaryngoscope blade would visualise a higher percentage of glottic opening compared with a Macintosh videolaryngoscope blade in patients with expected difficult airways. METHODS: We conducted an open-label, patient-blinded, randomised controlled trial in adult patients scheduled to undergo elective ear, nose and throat or oral and maxillofacial surgery, who were anticipated to have a difficult airway. All airway operators were consultant anaesthetists. Patients were allocated randomly to tracheal intubation with either hyperangulated (C-MAC D-BLADE™) or Macintosh videolaryngoscope blades (C-MAC™). The primary outcome was the percentage of glottic opening. First attempt success was designated a key secondary outcome. RESULTS: We assessed 2540 adults scheduled for elective head and neck surgery for eligibility and included 182 patients with expected difficult airways undergoing orotracheal intubation. The percentage of glottic opening visualised, expressed as median (IQR [range]), was 89 (69-99 [0-100])% with hyperangulated videolaryngoscope blades and 54 (9-90 [0-100])% with Macintosh videolaryngoscope blades (p < 0.001). First-line hyperangulated videolaryngoscopy failed in one patient and Macintosh videolaryngoscopy in 12 patients (13%, p = 0.002). First attempt success rate was 97% with hyperangulated videolaryngoscope blades and 67% with Macintosh videolaryngoscope blades (p < 0.001). CONCLUSIONS: Glottic view and first attempt success rate were superior with hyperangulated videolaryngoscope blades compared with Macintosh videolaryngoscope blades when used by experienced anaesthetists in patients with difficult airways.

Hyperangulated blades or direct epiglottis lifting to optimize glottis visualization in difficult Macintosh videolaryngoscopy: a non-inferiority analysis of a prospective observational study.

Purpose: It is unknown if direct epiglottis lifting or conversion to hyperangulated videolaryngoscopes, or even direct epiglottis lifting with hyperangulated videolaryngoscopes, may optimize glottis visualization in situations where Macintosh videolaryngoscopy turns out to be more difficult than expected. This study aims to determine if the percentage of glottic opening (POGO) improvement achieved by direct epiglottis lifting is non-inferior to the one accomplished by a conversion to hyperangulated videolaryngoscopy in these situations. Methods: One or more optimization techniques were applied in 129 difficult Macintosh videolaryngoscopy cases in this secondary analysis of a prospective observational study. Stored videos were reviewed by at least three independent observers who assessed the POGO and six glottis view grades. A linear mixed regression and a linear regression model were fitted. Estimated marginal means were used to analyze differences between optimization maneuvers. Results: In this study, 163 optimization maneuvers (77 direct epiglottis lifting, 57 hyperangulated videolaryngoscopy and 29 direct epiglottis lifting with a hyperangulated videolaryngoscope) were applied exclusively or sequentially. Vocal cords were not visible in 91.5% of the cases with Macintosh videolaryngoscopy, 24.7% with direct epiglottis lifting, 36.8% with hyperangulated videolaryngoscopy and 0% with direct lifting with a hyperangulated videolaryngoscope. Conversion to direct epiglottis lifting improved POGO (mean + 49.7%; 95% confidence interval [CI] 41.4 to 58.0; p < 0.001) and glottis view (mean + 2.2 grades; 95% CI 1.9 to 2.5; p < 0.001). Conversion to hyperangulated videolaryngoscopy improved POGO (mean + 43.7%; 95% CI 34.1 to 53.3; p < 0.001) and glottis view (mean + 1.9 grades; 95% CI 1.6 to 2.2; p < 0.001). The difference in POGO improvement between conversion to direct epiglottis lifting and conversion to hyperangulated videolaryngoscopy is: mean 6.0%; 95% CI -6.5-18.5%; hence non-inferiority was confirmed. Conclusion: When Macintosh videolaryngoscopy turned out to be difficult, glottis exposure with direct epiglottis lifting was non-inferior to the one gathered by conversion to hyperangulated videolaryngoscopy. A combination of both maneuvers yields the best result. Clinical trial registration: ClinicalTrials.gov, NCT03950934.

VivaSight Single-Lumen Tube Combined With Hyperangulated Videolaryngoscopy to Rescue Failed Tracheal Intubation in a Patient With Goldenhar Syndrome: A Case Report.

This report describes a patient with Goldenhar syndrome undergoing anesthesia for whom Macintosh videolaryngoscopy failed, as the epiglottis was adhered to the posterior pharynx and could not be lifted with a tracheal introducer (Cormack-Lehane grade 3B). Hyperangulated videolaryngoscopy revealed only the arytenoids (Cormack-Lehane grade 2B), even after direct lifting of the epiglottis, and endotracheal tube advancement failed due to unclear tissue resistance. Hyperangulated videolaryngoscopy was combined with a tube-mounted camera (VivaSight single lumen tube). The combination of both camera perspectives was successfully used to allow placement of the endotracheal tube underneath the epiglottis and through the vocal cords.

Elective Tracheal Intubation With the VieScope-A Prospective Randomized Non-inferiority Pilot Study (VieScOP-Trial).

Background: Tracheal intubation is commonly performed after direct laryngoscopy using Macintosh laryngoscopes (MacL), but visualization of the larynx may be inadequate. The VieScope (VSC) as a new type of laryngoscope consisting of a straight, shielded, illuminated tube used to perform intubation via a bougie was investigated in this prospective randomized trial in patients without expected difficult airways. Methods: With ethics approval, 2 × 29 patients for elective surgery were randomized 1:1 to intubation with VSC or MacL. Endpoints were first attempt success rates (FAS), Percentage of Glottis Opening Scale (POGO), time to intubation (TTI), and difficulty ratings on visual analog scales (0-100, lower values better). Data are given as mean ± standard deviation. Results: The FAS was 83 ± 38% for VSC and 86 ± 34% for MacL (P = 0.723). For VSC, POGO was 86 ± 17% and for MacL 68 ± 30% (P = 0.007). TTI for VSC was 93 ± 67s vs. 38 ± 17 for MacL (P < 0.001). Difficulty of intubation was rated 23 ± 22 for VSC vs. 18 ± 22 for MacL (P = 0.422), viewing conditions 12 ± 15 vs. 24 ± 25 (P = 0.031), and difficulty of tube placement was rated 27 ± 30 vs. 7 ± 8 (P = 0.001). Conclusion: No difference in FAS was detected between VSC and MacL. Visualization of the larynx was superior using the VSC, while TTI was prolonged and tube placement via bougie was more challenging. The VSC could be an alternative to MacL in patients with difficult laryngoscopy, but this should be investigated further in patients with expected difficult airways.