2006 OPEN FORUM Abstracts
DOES EZPAP DELIVER PREDICTABLE AIRWAY PRESSURES?
Black PJ, CRT RCP, Gnahn ER, CRT RCP,
Loechler RM, CRT RCP,
Peterson WV, CRT RCP CPFT,
Sampson KD, CRT RCP CPFT,
Witzke SM, CPFT,
Findlay JY, M.B.Ch.B., Stroetz RW, RRT; University of Minnesota-Mayo Clinic College of
Medicine, Rochester, MN
Background: The EzPAP (DHD Healthcare, Wampsville , NY ) is a device for lung expansion therapy. The EzPAP produces positive airway pressure throughout the breathing cycle via flow from an air or oxygen flow meter and flow amplification using the coanda effect. We investigated the pressure characteristics obtained using the EzPAP at various oxygen flow rates in a bench top simulation. We hypothesized that EzPAP devices deliver predictable airway pressures at given flows.
Methods: The testing apparatus consisted of a Michigan Test Lung Model 1600 (Michigan Instruments Inc., Grand Rapids, MI) connected to an 840 Ventilator (Puritan Bennett, Pleasanton, CA) set to deliver tidal volume 410mL, frequency 12, I:E ratio 1:3, descending-ramp waveform. Total compliance was 0.16L/cmH2O. The system simulated spontaneous respiration. The EzPAP devices were connected to this system and flows of 5, 8, 10, 12, 15L/min O2 delivered via a flow meter. Resulting inspiratory and expiratory pressures were measured by an in-line 50cmH20 transducer (Celesco Transducer Products, Inc, Chatsworth , CA ) and recorded on a chart recorder for analysis.
Results: Twenty EzPAP devices were tested. Mean high (exhalation) and low (inhalation) pressures (± SD) are shown in figure 1. On two (10%) EzPAP devices the manometers were noted to be stuck throughout the testing. One EzPAP, compared to the other nineteen in our study, delivered pressures in excess of 7cmH2O above the mean at a flow of 15L/min.
Conclusions: In a bench simulation of spontaneous respiration the EzPAP results in predictable airway pressures at delivered flows. Practitioners can use the device by setting delivered flows to obtain the desired airway pressures. However, setting the EzPAP at flows greater than 12L/min will develop high pressures and suggests practitioners should use the EzPAP with some caution at higher flows. In regard to the defective EzPAP pressure manometers, practitioners should be aware of potential problems with this part of the device.