2001 OPEN FORUM Abstracts
PRESSURE/FLOWCHARACTERISTICS OF THE EZPAP POSITIVE AIRWAY PRESSURE THERAPY SYSTEM
Snyder, RJ RRT, Slaughter,SL RRT, Chatburn, R RRT, FAARC University Hospitals of Cleveland,Cleveland, Ohio
BACKGROUND: The EzPAP positiveairway pressure therapy system is indicated ?for lung expansion therapy andthe treatment and prevention of atelectasis?. The device generates positiveairway pressure using flow input from a standard air or oxygen flowmeter andmay be used with a nebulizer. The purpose of this study was to evaluate thepressure/flow characteristics of the EzPAP with and without a nebulizer.
METHODS: The gas inlet portof the EzPAP was connected to an air flowmeter. The pressure monitoring portwas attached to a pressure gauge calibrated with a water manometer. We measuredthe inspiratory and expiratory pressures with 3 normal volunteers inhaling andexhaling normally. Input flows were adjusted in 1 L/min increments from 0 to15 L/min. The experiment was repeated with a nebulizer attached. The nebulizerwas powered by a flowmeter set to 6 and 8 L/min. Each experimental conditionwas evaluated 3 times. Data were analyzed with linear regression.
RESULTS: The addition of anebulizer had little effect on the airway pressures generated. The data belowshow airway pressure as a function of the flow set on the flowmeter for allexperiments combined. The coefficient of determination (r2) was 0.88. The systemmaintained airway pressure throughout the respiratory cycle with the inspiratorypressure averaging 45% of expiratory. The chart illustrates expiratory data.
EXPERIENCE: The EzPAP wasvery easy to setup and adjust. Breathing on the device was similar to a PEPdevice except that inspiratory pressure was elevated. The volunteers commentedthat they felt a noticeable increase in FRC. With the use of higher pressures/flows,subjects felt they needed to actively exhale.
Conclusions:The EzPAP deliversreliable and controllable pressures within a clinically useful range for lungexpansion therapy. An easily remembered equation allows prediction of the flownecessary to achieve a desired pressure.