Emergency airway management - comparison of different strategies in an unprotected airway

Objectives: Gastric inflation and regurgitation of stomach contents are maj or hazards of bag-valve-mask ventilation in an emergency. The purpose of ou r study was to determine lung ventilation and gastric inflation when using the bag-valve-face mask, laryngeal mask, and combitube with different sizes of self-inflating bags (max. volume: 700, 1100, 1500 ml). Methods: Twenty-six training emergency doctors without prior extensive trai ning in emergency airway management volunteered for our study and ventilate d a bench model simulating an unintubated respiratory arrest patient with b ag-valve-face mask, laryngeal mask, and combitube using paediatric, medium size, and adult self-inflating bags. Lung and gastric tidal volume, as well as lung and gastric peak airway pressure were measured with respiratory mo nitors and a pneumotachometer. Results: When using either the combitube or the laryngeal mask, the paediat ric vs. medium-size and adult self-inflating bag resulted in significantly (P < .001) lower mean <plus/minus> SEM lung tidal volumes (328 +/- 34 vs. 6 26 +/- 65 vs. 654 +/- 69 ml; and 368 +/- 30 vs. 532 +/- 48 vs. 692 +/- 67 m i, respectively). No gastric inflation occurred with the combitube, while g astric inflation was comparably low when using the laryngeal mask with eith er ventilation bag (3 +/- 2 vs. 7 +/-4 vs. 6 +/-3 ml P=NS). The paediatric vs. medium-size and adult self-inflating bag in combination with the bag-va lve-face mask resulted in comparable lung tidal volumes (250 +/- 23 vs. 313 +/- 24 vs. 282 +/- 38 ml, P = NS); but significantly (P<.01) lower gastric tidal volumes (147 <plus/minus> 23 vs. 206 +/- 24 vs. 267 +/- 23 ml). Conclusions: Both the laryngeal mask and the combitube proved to be valid a lternatives for the bag-valveface mask in our experimental model. The mediu m size self-inflating bag seems to be adequate when using either the laryng eal mask or the combitube.