Verifying PEEP Delivery During Bag-Valve-Mask Ventilation

Abstract

Background:

Bag-valve-mask (BVM) ventilation is a vital emergency skill for respiratory therapists. Manual ventilation requires PEEP to be applied and delivered directly to a patient’s airway. Fluctuations in PEEP can be dangerous for pediatric patients and cause lung injury or even death. Self-inflating BVM devices have set PEEP valves and are available from multiple manufacturers. The SunMed AirFlow (SM) is a competitively priced BVM compared to our current product, the Carefusion Airlife (CF). We aimed to test the functionality of maintaining PEEP at various levels via both BVM products.

Methods:

In an IRB-exempt bench study, BVM ventilation was assessed via a Philips NM3 monitor while manually ventilating a pediatric Michigan Test Lung (compliance 0.004 mL/cm H₂O). Two identical models were used with the SM and CF BVMs. Both models included 3 trials for each PEEP level by manually ventilating with a delta P of 20 cm H₂O and respiratory rate 20 for 30 seconds with the PEEP valve set at 5 (trial 1), 10 (trial 2), and 15 cm H₂O (trial 3). The same trained RT was utilized to manually ventilate during the trials. PEEP data was recorded from the NM3 monitor at the 10, 20 and 30 sec intervals.

Results:

Difference (%) in PEEP measured to set PEEP on the BVM for each trial were calculated. The CF BVM measured PEEP differed from set PEEP 0% (5 cm H₂O), 16% (10 cm H₂O) and 8.7% (15 cm H₂O). The SM BVM measured PEEP differed from set PEEP 82.4% (5 cm H₂O), 64% (10 cm H₂O) and 71.33% (15 cm H₂O). The difference between CF and SM PEEP monitored was statistically significant (P = 0.0085).

Conclusions:

The SM BVM did not maintain the set PEEP value in any of our trials, demonstrating a significant loss of PEEP during manual ventilation. Our current CF BVM product provides a more reliable and consistent delivery of PEEP with measured differences of no more than 16% from set PEEP even with trained user variability. More studies should be performed to evaluate this relationship in clinical practice as well as with additional products available.