Maximum FIO2 in minimum time depending on the kind of resuscitation bag and oxygen flow

Abstract

Objective: To analyze what FIO2 can be reached, and how long it takes using the different autoinflated resuscitation bags and increasing oxygen flows. Design: Experimental analysis on the effect of three different models of autoinflated resuscitation bag and increasing oxygen flows in the final FIO 2 and time spent to reach it. Setting: Laboratory, with a gas analyzer and a lung simulator to measure inspired FIO2. Interventions: Simulated cardiopulmonary resuscitation. Three different autoinflated resuscitation bags were studied; A, the classic one with oxygen delivery directly into the bag, without reservoir, B, a new one without the reservoir device; and C, a new one with the reservoir device properly implemented. Increasing oxygen flows were administered until FIO2 stabilized. Results: With model A the maximum FIO2 reached was 0.73 in 70 s using a 20 l/min oxygen flow. With model B the maximum FIO2 reached was 0.65 in 90 s using a 20 l/min oxygen flow. The best FIO2 (0.99) was reached using model C in 55 s with 12 l/min oxygen flow. In the three models a high correlation between oxygen flow and FIO2 was found (r>0.8). Conclusions: It is mandatory to use model C resuscitation autoinflated bag with 12 l/min of oxygen flow during the resuscitation maneuvers. Using another autoinflated bag model, maximum oxygen flows (i.e., 20 l/min) are needed. The resuscitation autoinflated bags showed less effectiveness when they were not properly assembled.