Comparison of four channelled videolaryngoscopes to Macintosh laryngoscope for simulated intubation of critically ill patients: the randomized MACMAN2 trial

Background Videolaryngoscopes with an operating channel may improve the intubation success rate in critically ill patients. We aimed to compare four channelled videolaryngoscopes to the Macintosh laryngoscope used for intubation of a high-fidelity simulation mannikin, in a scenario that simulated critical illness due to acute respiratory failure. Results Of the 79 residents who participated, 54 were considered inexperienced with orotracheal intubation. Each participant used all five devices in random order. The first-pass success rate was 97.5% [95% CI 91.1–99.7] for Airtraq™, KingVision™, and Pentax AWS200™, 92.4% [95% CI 84.2–97.2] for VividTrac VT-A100™, and 70.9% [95% CI 59.6–80.6] for direct Macintosh laryngoscopy. The first-pass success rate was significantly lower with direct Macintosh laryngoscopy than with the videolaryngoscopes (p < 0.0001 for Airtraq™, KingVision™, Pentax AWS200™, and VividTrac VT-A100™). Conclusion The Airtraq™, KingVision™, and Pentax AWS200™ channelled videolaryngoscopes produced high first-pass success rates with a lower boundary of the 95% CI above 90%. A multicentre, randomised controlled clinical study comparing channelled videolaryngoscopy to direct laryngoscopy should include one of these three videolaryngoscopes.

Comparison of the novel VieScope with conventional and video laryngoscope in a difficult airway scenario – a randomized, controlled simulation trial

Background Endotracheal intubation continues to be the gold standard for securing the airway in emergency situations. Difficult intubation is still a dreadful situation when securing the airway. Objective To compare VieScope with Glidescope and conventional Macintosh laryngoscopy (MAC) in a simulated difficult airway situation. Methods In this randomized controlled simulation trial, 35 anesthesiologists performed endotracheal intubation using VieScope, GlideScope and MAC in a randomized order on a certified airway manikin with difficult airway. Results For the primary endpoint of correct tube position, no statistical difference was found (p = 0.137). Time until intubation for GlideScope (27.5 ± 20.3 s) and MAC (20.8 ± 8.1 s) were shorter compared to the VieScope (36.3 ± 10.1 s). Time to first ventilation, GlideScope (39.3 ± 21.6 s) and MAC (31.9 ± 9.5 s) were also shorter compared to the VieScope (46.5 ± 12.4 s). There was no difference shown between handling time for VieScope (20.7 ± 7.0 s) and time until intubation with GlideScope or MAC. Participants stated a better Cormack & Lehane Score with VieScope, compared to direct laryngoscopy. Conclusion Rate of correct tracheal tube position was comparable between the three devices. Time to intubation and ventilation were shorter with MAC and Glidescope compared to VieScope. It did however show a comparable handling time to video laryngoscopy and MAC. It also did show a better visualization of the airway in the Cormack & Lehane Score compared to MAC. Trial registration The study was registered at the German Clinical Trials Register www.drks.de (Identifier: DRKS00024968) on March 31st 2021.

Comparison of learning direct laryngoscopy using a McGrath videolaryngoscope as a direct versus indirect laryngoscope: a randomized controlled trial

Objective Tracheal intubation using a direct laryngoscope is difficult to teach. The McGrath videolaryngoscope, a Macintosh-like device with a camera, can be used as a direct laryngoscope to educate novices under supervision using the screen. We compared the effect on Macintosh laryngoscopy skills following training with a McGrath videolaryngoscope as a direct versus indirect laryngoscope. Methods Thirty-seven participants were randomized into direct and indirect groups according to the training method using a McGrath videolaryngoscope. Participants attempted Macintosh direct laryngoscopy in normal and difficult airway scenarios. The primary endpoint was the intubation time, and the rate of successful intubation, dental trauma, and difficulty were secondary outcomes. Results The intubation time after education decreased significantly in both groups and was significantly shorter in the direct group than in the indirect group across time. The difficulty degree in the direct group was lower than that in the indirect group across time; however, the rate of dental trauma was not significantly different. Conclusion Both direct and indirect laryngoscopy using a McGrath videolaryngoscope improved the performance of Macintosh direct laryngoscopy in novices, while direct laryngoscopy using a McGrath videolaryngoscope demonstrated better educational effects than indirect laryngoscopy. Registered at ClinicalTrials.gov (NCT03471975).

Radiological indicators to predict the application of assistant intubation techniques for patients undergoing cervical surgery

Background We aimed to distinguish the preoperative radiological indicators to predict the application of assistant techniques during intubation for patients undergoing selective cervical surgery. Methods A total of 104 patients were enrolled in this study. According to whether intubation was successfully accomplished by simple Macintosh laryngoscopy, patients were divided into Macintosh laryngoscopy group (n = 78) and Assistant technique group (n = 26). We measured patients’ radiographical data via their preoperative X-ray and MRI images, and compared the differences between two groups. Binary logistic regression model was applied to distinguish the meaningful predictors. Receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to describe the discrimination ability of indicators. The highest Youden’s index corresponded to an optimal cut-off value. Results Ten variables exhibited significant statistical differences between two groups (P < 0.05). Based on logistic regression model, four further showed correlation with the application of assistant techniques, namely, perpendicular distance from hard palate to tip of upper incisor (X2), atlanto-occipital gap (X9), angle between a line passing through posterior-superior point of hard palate and the lowest point of the occipital bone and a line passing through the anterior-inferior point and the posterior-inferior point of the second cervical vertebral body (Angle E), and distance from skin to hyoid bone (MRI 7). Angle E owned the largest AUC (0.929), and its optimal cut-off value was 19.9° (sensitivity = 88.5%, specificity = 91.0%). the optimal cut-off value, sensitivity and specificity of other three variables were X2 (30.1 mm, 76.9, 76.9%), MRI7 (16.3 mm, 69.2, 87.2%), and X9 (7.3 mm, 73.1, 56.4%). Conclusions Four radiological variables possessed potential ability to predict the application of assistant intubation techniques. Anaesthesiologists are recommended to apply assistant techniques more positively once encountering the mentioned cut-off values.