Airway pressure release ventilation.
BACKGROUND
Elevated airway pressures during mechanical ventilation are associated with hemodynamic compromise and pulmonary barotrauma. We studied the cardiopulmonary effects of a pressure-limited mode of ventilation (airway pressure release ventilation) in patients with the adult respiratory distress syndrome.


METHODS
Fifteen patients requiring intermittent mandatory ventilation (IMV) and positive end-expiratory pressure (PEEP) were studied. Following measurement of hemodynamic and ventilatory data, all patients were placed on airway pressure release ventilation (APRV). Cardiorespiratory measurements were repeated after a 2-hour stabilization period.


RESULTS
During ventilatory support with APRV, peak inspiratory pressure (62 +/- 10 vs 30 +/- 4 cm H2O) and PEEP (11 +/- 4 vs 7 +/- 2 cm H2O) were reduced compared with IMV. Mean airway pressure was higher with APRV (18 +/- 5 vs 24 +/- 4 cm H2O). There were no statistically significant differences in gas exchange or hemodynamic variables. Both cardiac output (8.7 +/- 1.8 vs 8.4 +/- 2.0 L/min) and partial pressure of oxygen in arterial blood (79 +/- 9 vs 86 +/- 11 mm Hg) were essentially unchanged.


CONCLUSIONS
Our results suggest that while airway pressure release ventilation can provide similar oxygenation and ventilation at lower peak and end-expiratory pressures, this offers no hemodynamic advantages.
Davis
K
K
Department of Surgery, University of Cincinnati, Medical Center, Ohio.
Johnson
D J
DJ
Branson
R D
RD
Campbell
R S
RS
Johannigman
J A
JA
Porembka
D
D
D000328:Adult; D000368:Aged; D000403:Airway Resistance; D001784:Blood Gas Analysis; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007385:Intermittent Positive-Pressure Ventilation; D008170:Lung Compliance; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D011175:Positive-Pressure Respiration; D011312:Pressure; D011659:Pulmonary Gas Exchange; D012121:Respiration, Artificial / Q000379:methods*; D012128:Respiratory Distress Syndrome / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy*; D017211:Treatment Failure
D010100:Oxygen