Date of Award
Open Access Thesis
Medical Doctor (MD)
Christopher C. Baker, M.D.
In the late 1960's, a new method for advanced airway management in the pre-hospital setting, the esophageal obturator airway (EOA), was introduced. Ever since, it has been the subject of much discussion over whether it was an effective replacement or alternative to the device traditionally used for airway protection, the endotracheal (ET) tube. Much of the comment has been in the form of personal opinion and anecdotal reports. Each device is in use by paramedics operating out of two hospitals in southern Connecticut, the EOA at Yale New Haven Hospital and the ET at Norwalk Hospital. The ambulance and emergency room records at both institutions were examined for a six-month period in 1983 to see if the efficacy of the two techniques could be compared in any meaningful way. In two similar groups of patients requiring out-of-hospital intubation, there was no statistically significant difference in overall survival rates (22%-ET; 20.5%-EOA), nor in the incidence of complications (22.6%-ET intubated, 25%-EOA intubated), with ET tubes and those intubated with EOAs. However, there was a difference in intubation success, with the ET airway being successfully placed by the paramedics at Norwalk 74% of the time, compared with successful placement of the EOA only 57% of the time at Yale. And the incidence of failure to intubate when clinically indicated was as high as 18% at Yale, compared to 10% at Norwalk. Although the adequacy of ventilation was not demonstrated to be statistically different for EOAs versus ETs, there is a suggestion in the arterial blood gas data that the ET may provide "clinically" better ventilation than the EOA. Equally significant was the finding that overall adequacy of ventilation, with either device, in the prehospital period was disappointingly low: 21% at Norwalk, 8% at Yale (no significant difference between centers at P>.05). A review of experience data of the various rescue services showed that there were insufficient opportunities, in most cases, to intubate in the field (that is, there are more paramedics working in these areas than there are patients requiring out-of-hospital intubation), thus placing a heavy burden on the supporting hospitals to provide sufficient experience in the hospital for the paramedics to maintain adequate intubation skill levels. This study concludes that the ET airway should probably be the first-line device employed for prehospital airway management, when re sources and patient density are sufficient to maintain adequate skill levels. The EOA should be used as a second-line device, when logistics do not permit use of the ET airway, or as the primary airway in areas with insufficient population and ambulance call density to support the ET training protocol. The EOA, properly inserted and managed, can be as effective as the ET airway. But, more importantly, skill levels of paramedics using both devices need to be upgraded significantly (the use of the EOA more so than the ET tube). And, the EOA should no longer be considered a "simple, easy-to-use" device.
Phillips, Roger Morgan, "Pre-Hospital Airway Management : A Comparison of Esophageal and Endotracheal Intubation" (1984). Yale Medicine Thesis Digital Library. 513.