2002 OPEN FORUM Abstracts
MINIMUM INSPIRATORY PRESSURE LEVELS DURING SIMULATED SPONTANEOUS BREATHING USING AN EZPAPTM SYSTEM. A BENCH STUDY
Susan R. Ogrinc, RRT, James E. Martin, RRT, Departments of Pulmonary Services, and Pediatrics, MetroHealth Medical Center, Cleveland, OH
BACKGROUND: Positive Airway Pressure (PAP) devices are used for secretion mobilization, and prevention and treatment of atelectasis. The EzPAPTM Positive Airway Pressure Therapy System provides positive pressure during the total respiratory cycle. Administering 5-15 L/m of compressed gas into the gas inlet port is amplified fourfold by the coanda effect, which produces the desired therapeutic pressure level. The purpose of this study was to see if positive pressure was maintained throughout the respiratory cycle during simulated spontaneous breathing.
METHOD: A two-section test lung (2600I; Michigan Instruments) was used to simulate spontaneous breathing. A Puritan Bennett 7200 ventilator in volume mode powered the driving chamber. The EzPAP was attached to the distal port of the test chamber. A coupler was attached between the two compartments of the test lung. Peak Inspiratory Flow Rates (PIFR) of 10, 15, 20, 25, 30, 40, and 60L/m were achieved by varying the ventilator tidal volume and peak flow rates. The resistance (RP5) on the test chamber remained constant. An airway monitoring device (Bicore CP 100) was placed between the EzPAP and test chamber and used to set spontaneous PIFR and measure pressures. An anoid manometer was attached to the pressure port of the EzPAP. During simulated spontaneous breathing, the lowest inspiratory pressures were recorded using 5,10 and 15 L\m of Oxygen. Two additional devices were randomly checked at various PIFR to ensure reproducibility of results (+1 cm H2O).
RESULTS: The lowest inspiratory pressure levels are recorded in the chart below. PIFR from 0-30 L\m maintained positive pressures for all three-oxygen settings. At 40 L\m the 5 L\m oxygen setting resulted in an ambient pressure reading. Only 15L\m oxygen maintained a positive pressure during inspiration at all flowrates tested.
CONCLUSION: EzPAP provides positive pressure throughout the respiratory cycle except for extreme inspiratory flow rates making it a suitable PAP adjunct. Use of a pressure manometer and the continual reinforcement of correct breathing can ensure the desired pressures.