Review of: Hoyle JD, Jones JS, Deibel M, et al: Comparative study of airway management techniques with restricted access to patient airway. Prehospital Emergency Care. 11(3):330-336, 2007.
This study conducted by the Grand Rapids Medical Education and Research Center examines the number of attempts required and the time to successfully ventilate a mannequin placed in non-traditional scenarios. They compared the endotracheal tube (ET), Combitube (CT) and the Laryngeal Mask Airway (LMA). They also compared the times and success rates of 25 emergency medicine residents, nine emergency medicine faculty and 22 paramedics.
The mannequins were placed in one of three positions: 1) supine under a table with the head abutting a table and a table overlying them, 2) sitting upright with access only from behind, and 3) lying on its side with access only by lying on the floor facing it. The supine and side scenarios simulated a confined-space rescue, and the access from behind simulated a trapped-vehicle patient.
They found no significant difference between residents, faculty and paramedics in the number of attempts needed to successfully ventilate the mannequin. EMT-Ps demonstrated significantly faster times to successful ventilation for all scenarios versus physicians except for the mannequin lying on its side, for which no significant difference was noted. Specifically, in the supine scenario with ET, the EMT-P median time was 57 seconds, whereas the physician median time was 96 seconds. The time to ventilation for all scenarios was less with the LMA versus ET, or CT versus ET, except in the sitting scenario where ET and CT were comparable
They concluded, In this mannequin model of restricted airway access, LMA resulted in significantly faster times to ventilation versus ET and CT in all but one scenario.
Finally! We re starting to realize that intubation in the prehospital setting requires a unique knowledge and skill set. Despite having less experience with both ET and LMA, the paramedics were able to ventilate the patient in less time than the doctors. Perhaps this is, as the authors noted, a reflection of the fact that paramedics often have little help in the field and must be confident in dealing with such life-threatening scenarios on their own.
This further reinforces my belief that, just like the military, train like you fight and you will fight like you train. Prehospital intubation is never like the sterile environment of the OR, and we should support training and educating our providers to deal with real life scenarios.
Clearly, the role of non-visualized airways is highlighted by this study. Although debate continues over which is the most appropriate device, this study shows that the LMA is more efficient. It will be interesting to see similar studies comparing these devices with the King LT and Cobra.