Rescue Mask with Prefabricated Leak for Reduction of Accidental Stomach Inflation During Lay Rescuer Ventilation

Objective: To evaluate the efficacy of a simple method to minimize gastric inflation in unprotected airways during resuscitation procedures. Methods: Ventilation of an airway simulator by use of a hose extended mask with leak and without leak and with or without additional oxygen (15 litres per minute). Experimental settings with artificial lung at a compliance = 300ml/ kPa and resistance = 0,5 kPa/ l/ s. Lower oesophageal sphincter pressure = 0,5 kPa. Results: Tidal volumes were significantly lower with integrated leak than with the leak proof mask (medians: 406 vs. 681ml), gastric inflation was significantly reduced by use of the mask with leak (medians: 2300 ml vs. 7300ml) and inspiratory oxygen fraction was significantly higher when oxygen was added. Conclusion: Gastric inflation may markedly be reduced, however not excluded, when a mask with a prefabricated leak is used instead of achieving a leak proof mask ventilation technique. With additive oxygen only the inspiratory oxygen fraction will be significantly higher which supports the benefit of additional oxygen.