Modified closed circuit underwater breathing apparatus LAR VII and laryngeal mask airway as adjuncts for dive buddy artificial ventilation

This study evaluated the feasibility of using the modified semiclosed circu it underwater rebreathing system [URS] LAR VII in connection with a larynge al mask airway (LMA) as an expedient ventilatory adjunct in an operational setting. Fourteen combat swimmers, unfamiliar with this equipment, underwen t cardiopulmonary resuscitation (CPR) mannequin training using these device s. Eighteen subjects, using a standard AMBU bag for ventilation, served as controls. Thirteen test persons were able to ventilate with the modified UR S. Tidal volumes were significantly lower with the LAR VII/LMA than with th e AMBU bag (medians, 350 vs. 800 mt). No significant difference was found i n total time required for 10 CPR cycles (medians, 78 vs. 68.5 seconds). The median delay between recognition of cardiac arrest and first chest compres sion, however, was markedly increased with the LAR VII/LMA than with the AM BU bag (medians, 76.5 vs. 14.5 seconds). After proper training, divers migh t use a modified URS such as the LAR VII for CPR in connection with a LMA, Lower tidal volumes might prevent gastric inflation. Chest compression shou ld be continued during LMA insertion.