An improvised "blow glove" device produces similar PEP values to a commercial PEP device: An experimental study

Background: Postoperative positive expiratory pressure (PEP) therapy promotes increased lung volume, secretion clearance, and improved oxygenation. Several commercial devices exist that produce recommended PEP values (10-20 cmH₂O) when the patient breathes through a fixed orifice resistor. It was hypothesized that an inexpensive, improvised "blow glove" device would produce similar PEP values over a wider range of expiration volumes and flow rates. Methods: PEP for different expiration volumes (400-2000 mL) and expiratory flow rates (10-80 L/min) was compared between a commercial PEP device (Resistex, Mercury Medical, Clearwater, FL) and an improvised "blow glove" device, recorded by a Vela ventilator (CareFusion, San Diego, CA). Dynamics in positive end expiratory pressure (PEEP) values were evaluated following five consecutive expirations. The "blow glove" device was evaluated using various glove compositions and sizes. Results: The improvised "blow glove" device produced a significantly higher rate of PEP values in the recommended range than the Resistex device (88.9% vs. 20%, p < 0.0001). No significant difference was observed between small and large glove sizes (88.9% vs. 82.9%, p > 0.05), but the powdered latex glove showed a significantly higher rate of PEP values in the recommended range than the powder-free latex glove (88.9% vs. 44.4%, p < 0.001). Conclusions: A "blow glove" PEP device using a powdered latex glove produces PEP values in the recommended range over a wider spectrum of expiratory flow rates and expiration volumes than a commercial PEP device.