The Efficacy of the Storz Miller 1 Video Laryngoscope in a Simulated Infant Difficult Intubation

Abstract

Several studies have shown video laryngoscopy to be a useful technique in the management of patients in whom glottic exposure by direct laryngoscopy is difficult. We conducted this study as a preliminary investigation comparing the Storz DCI Miller 1 video laryngoscope (VL, Karl Storz GmbH, Tuttlingen, Germany) and direct laryngoscopy with a Miller 1 laryngoscope (DL) in an infant manikin model simulating difficult direct laryngoscopy. We hypothesized that compared with DL, VL would provide a better glottic view but would be associated with a longer time to intubation because of the different skill set required when using video intubation. A Laerdal infant airway management training manikin (Laerdal Medical, Wappingers Falls, NY) was adapted using cloth tape to limit cervical spine mobility. Thirty-two attending pediatric anesthesiologists attempted tracheal intubation of the infant manikin using VL and DL in randomized order. The best laryngeal view with each laryngoscope and time to intubation were documented. There was a significant difference in the distributions of laryngoscopy grades between VL and DL (P < 0.001), with the VL giving a better laryngeal view. Forty percent of anesthesiologists reported a Grade 3 or 4 view with DL; all of which were converted to Grades 1 and 2 with VL. The median grade with interquartile range was two (2-3) for DL and one (1-2) for VL (P < 0.001). Seventy-eight percent of participants reported an improvement of at least one grade in laryngeal view with VL compared with DL. There were two failed intubations using DL and none using VL. Time to intubation was similar between the two techniques. The Storz Miller 1 VL blade improved glottic exposure in a simulated difficult laryngoscopy compared with direct laryngoscopy with a standard Miller 1 blade without increasing the time to intubation.