The effect of a PEEP valve on a Laerdal neonatal self-inflating resuscitation bag

Background: Self-inflating bags are used to provide ventilation during neonatal resuscitation. However, they cannot provide positive end expiratory pressure (PEEP) unless a PEEP valve is attached. The ability of Laerdal neonatal self-inflating bags fitted with PEEP valves to reliably deliver PEEP is unclear. The aim of this study was to measure the delivered PEEP at different set PEEP levels and inflation rates. Methods: We connected disposable and non-disposable 240 mL Laerdal self-inflating resuscitation bags fitted with PEEP valves to a leak-free test lung. We measured PEEP delivered with the valve set at 5, 7 and 10 cm H2O whilst inflating the test lung at rates of 20, 40 and 60 min. Studies were done with 8 L/min of gas flow and with no gas flow. Results: The PEEP delivered was close to the set level immediately after inflation but declined rapidly between inflations. The mean PEEP was higher with faster ventilation rates. When PEEP was set at 7 cm H2O, using a non-disposable bag, and an inflation rate of 60/min the mean (SD) PEEP was 5.4 (0.19) cm H2O. The PEEP delivered was unrelated to the gas flow into the device. Conclusion: The 240 mL Laerdal self-inflating bag with a PEEP valve delivers PEEP that loses pressure quickly. The level of PEEP delivered is less than that set, particularly at rates below 40/min.