Improved success rates using videolaryngoscopy in unexperienced users: a randomized crossover study in airway manikins

Abstract

BackgroundVideolaryngoscopy has been proven to be a safe procedure managing difficult airways in the hands of airway specialists. Information about the success rates in unexperienced users of videolaryngoscopy compared to conventional laryngoscopy is sparse. Therefore, we aimed to evaluate if there might be more success in securing an airway if the unexperienced provider is using a videolaryngoscope in simulated airways in a randomized manikin study. Differences between commonly used videolaryngoscopes were elucidated.MethodsA standardized hands-on workshop prior to the study was performed. For direct laryngoscopy (DL) we used a Macintosh laryngoscope, whereas for videolaryngoscopy (VL) we used the cMac, the dBlade, and a King Vision videolaryngoscope. Endotracheal intubations in three simulated normal and difficult airways were performed. Main outcome parameters were time to view and time to intubation. Cormack and Lehane (C + L) classification and the percentage of glottic opening (POGO) score were evaluated. After every intubation, the participants were asked to review the airway and the device used.Results22 participants (14.8 ± 4.0 intubations per year, mostly trauma surgeons) with limited experience in videolaryngoscopy (mean total number of videolaryngoscopy .4 ± .2) were enrolled. We found improved C + L grades with VL in contrast to DL. We saw similar data with respect to the POGO score, where the participants achieved better visibility of the glottis with VL. The hyperangulated blade geometries of videolaryngoscopes provided a better visibility in difficult airways than the standard geometry of the Macintosh-type blade. The subjective performance of the VL devices was better in more difficult airway scenarios.ConclusionsAfter a short introduction and hands-on training, a videolaryngoscope seems to be safe and usable by unexperienced providers. We assume a standard geometry laryngoscope is optimal for a patient with normal anatomy, whereas VL device with a hyperangulated blade is ideal for difficult airway situations with limited mouth opening or restricted neck movement.

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

“…A comparative mannikin study found that videolaryngoscopy with a Macintosh-like blade performed better than did channelled videolaryngoscopy for the normal airway, whereas the opposite was true for difficult airways [ 32 ]. In a study that used a mannikin with a normal airway, direct laryngoscopy was fastest and also provided a higher first-pass success rate than did the Airtraq™ in the hands of non-experts [ 33 ]. These differences with our results are due to the lower proportion of first-pass success with direct laryngoscopy intubation in our trial compared to previous studies: first-pass success rates ranged from 79 to 100% with direct laryngoscopy, even in the hands of non-experts, [ 32 – 35 ] compared to 71% in our study.…”

“…We made this choice, because the proportion of successful first-pass intubations with videolaryngoscopy performed by inexperienced operators on ICU patients was 67.7% in the MACMAN1 trial [ 10 ]. Two of the above-mentioned studies on mannikins used only a normal airway [ 33 , 35 ]. The mean POGO score by direct laryngoscopy ranged from 77 to 80 in the two studies reporting this variable [ 32 , 34 ], both of which simulated difficult airways, compared with 57 in our study.…”

Comparison of Glidescope® Go™, King Vision™, Dahlhausen VL, I‑View™ and Macintosh laryngoscope use during difficult airway management simulation by experienced and inexperienced emergency medical staff: A randomized crossover manikin study

“…In contrast to the Glidescope ® Go ™ , the Dahlhausen VL and the King Vision ™ with hyperangulated disposable blades, the blade of the I-View ™ one-size single-use VL has a standard Macintosh shape and is significantly longer. In a randomized crossover manikin study, Eismann and colleagues demonstrated, that the hyperangulated blade geometries of VLs provided a better view in difficult airway than the standard geometry of the Macintosh-type blade [ 24 ]. In addition, Schieren and colleagues showed that VLs with hyperangulated blades needed less force for intubation in difficult airways compared to Macintosh shaped laryngoscope blades [ 25 ].…”

Use of video laryngoscopes by inexperienced personnel in difficult intubations

“…The results show that video laryngoscopy was much more effective in achieving successful endotracheal intubation, especially in difficult airways with diminished oral cavity opening or limited neck movement. The video laryngoscopes allowed for much better visualization of the airway than the standard Macintosh laryngoscope [24]. A comparison of the use of several video laryngoscopes by a group of 50 inexperienced in intubation medical students, was also undertaken by Rendeki et al Participants tested a few different devices including King Vision, Airtraq and the Macintosh laryngoscope.…”