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.
