Laerdal infant resuscitators are unreliable as free-flow oxygen delivery devices

Laerdal Infant Resuscitators (Laerdal Medical Co., NY) are commonly used as free-flow oxygen delivery devices during neonatal resuscitation in situations where oxygen but not mechanical ventilation is desired. This study evaluates the performance of these resuscitators as free-flow oxygen devices. Efficiency was measured by comparing oxygen flow entering the resuscitator to oxygen flow delivered by the resuscitator. Clinical impact was assessed by measuring simulated patient fiO2. Three randomly selected resuscitator bags were tested for oxygen delivery efficiency by comparing oxygen inflow to outflow over an inflow range of 1 to 15 liters per minute (lpm). Measured outflow was 18-24% of inflow, demonstrating that as much as 82% of the oxygen flow escapes via the safety air inlet, safety blow-off valves, and other leaks. With the patient valve assembly removed, efficiency improved to 53-59%. Simulated fiO2 ranged from 0.23 to 0.68 at 5 lpm oxygen flow. We conclude that use of the Laerdal Infant Resuscitator for the delivery of free-flow oxygen, even with the valve assembly removed, generates highly variable patient fiO2. The use of self-inflating bags for delivery of oxygen without manual ventilation should be reconsidered.