Comparison of Video Versus Direct Laryngoscopy: A Prospective Prehospital Air Medical Services Study.

OBJECTIVE: Videolaryngoscopy (VL) in the prehospital setting remains controversial, with conflicting data on its utility. We compared C-MAC VL (Karl Storz, Tuttlingen, Germany) versus direct laryngoscopy (DL) in the prehospital setting, recording the grade of the glottic view, first pass success (FPS), overall success, and equipment functionality. METHODS: We conducted a prospective observational study with a convenience sample of 49 adult patients who were intubated by flight crew nurses and paramedics using the C-MAC videolaryngoscope from April to November 2013. We compared Cormack-Lehane (CL) grades of view for DL and VL, intubation success rates, and equipment functionality. RESULTS: CL grades 1 or 2 were obtained with 24 patients (49%) with DL and 45 patients (92%) with VL. Of the 25 patients (51%) who had a CL grade 3 or 4 view on DL, 22 of those patients (88%) converted to a CL grade 1 or 2 with VL (P < .001). There was an overall success rate of 96% and an FPS rate of 71%. The C-MAC videolaryngoscope was functional during intubation 100% of the time. CONCLUSION: VL improved glottic visualization compared with DL. The FPS and overall intubation success rates were similar to other published prehospital studies using VL. The C-MAC provided reliable, high-quality video despite demanding prehospital conditions.

Changes in Pediatric-Sized Endotracheal Tube Cuff Pressure With Elevation Gain: Observations in Ex Vivo Simulations and In Vivo Air Medical Transport.

OBJECTIVES: Prolonged excessive endotracheal cuff pressure greater than 30 cmH2O is thought to cause ischemic airway injury. Excessive cuff pressure with altitude gain during air medical transport has been previously described in adult patients. It is poorly understood how pediatric-sized endotracheal tube (ETT) cuffs behave with atmospheric pressure change during flight. METHODS: In ex vivo models 4.0, 6.0, and 8.0, ETTs restricted within scaled syringe tubing were inflated to 20 cmH2O. Pressure was measured against 1500 ft elevation gain in ground and flight models. In an in vivo observation of pediatric patient transport, change in cuff pressure was measured between takeoff and helicopter peak flight altitudes. RESULTS: In the ex vivo ground model, endotracheal cuff pressure increased linearly with altitude and exceeded 40 cmH2O in all tube sizes. Comparable pressure change was demonstrated in the flight model. No difference was demonstrated in the degree of pressure change between ETT sizes. In the in vivo observations during patient transport, pressure increase was consistent with that seen in the ex vivo models. CONCLUSIONS: Children who are intubated with cuffed ETTs for air medical transport are subject to excessive endotracheal cuff pressure at even low flight altitudes. Endotracheal tube size did not affect the degree of cuff pressure change, contrary to previous study. These findings need to be validated and correlated to patient clinical outcomes. The implications of these data need to be considered clinically particularly for prolonged transport of intubated pediatric patients at elevation.