2010 OPEN FORUM Abstracts
COMPARISON OF PEAK-EXPIRATORY FLOW RATE AND END-EXPIRATORY PRESSURE DURING AIRWAY PRESSURE RELEASE VENTILATION WITH THE DRAGER XL, VIASYS AVEA, PB 840 AND SERVO-I.
Ross Armstrong1, David Strong1, Lonny Ashworth2; 1St. Lukes Regional Medical Center, Boise, ID; 2Boise State University, Boise, ID
Background: Airway Pressure Release Ventilation (APRV) is a mode of ventilation that is used by some clinicians, in the management of patients with ARDS. By combining two different levels of CPAP, APRV allows the patient to breathe spontaneously at any point during the respiratory cycle. Frequently, during APRV the TimeLow is set to end when a percentage of the Peak-Expiratory Flow Rate (PEFR) is reached. The purpose of this study is to measure PEFR during TimeLow and End-Expiratory Pressure (EEP) at the end of TimeLow in APRV while ventilating an electronic lung simulator at three different levels of compliance. Method: The Hans Rudolph HR 1101 Electronic Lung Simulator was interfaced, using a size 8.0 ETT, to the Drager XL, Viasys Avea, Puritan Bennett 840 and Servo-i. Settings on the HR 1101 were: Resistance 12 cm H2O/L/sec, Compliance 15, 20 and 25 mL/cmH2O, Rate 30/minute, Amplitude 0, Effort Slope 15, % Inhale 33, Target Volume 3000 mL, Load Effort Normal. Data points were measured at intervals of 0.05 seconds. Each ventilator was placed in APRV at the following settings: TimeHigh 8 seconds, TimeLow 0.3 seconds, PressureHigh 25 cmH2O, PressureLow 0 cm H2O, Tube Compensation off. At each compliance setting, PEFR was measured as the greatest flowrate during TimeLow; EEP was measured at the point where TimeLow transitioned to TimeHigh. Results: At each compliance level the PB 840 had the highest PEFR measurements; the Viasys Avea had the lowest PEFR measurements. The lowest EEP was measured when using the Servo-i. The highest EEP varied depending upon the compliance level and the ventilator. Conclusion: When using an electronic lung simulator at three different levels of compliance, the EEP was within 1.5 cm H2O among the ventilators at each compliance level. However, the PEFR varied considerably among the ventilators. Because many clinicians set TimeLow based upon a percentage of PEFR, one should consider that the PEFR may vary depending upon the ventilator being used. Further studies are necessary to determine the impact of our findings on actual patients PEFR and EEP, and the associated clinical significance. Sponsored Research - None