The effect of airway pressure release ventilation on pulmonary catheter readings: Specifically pulmonary capillary wedge pressure in a swine model

Abstract

Background. Airway pressure release ventilation (APRV) is a mode of mechanical ventilation that theoretically believed to improve cardiac output by lowering right atrial pressure. However, hemodynamic parameters have never been formally assessed. Methods. Seven healthy swine were intubated and sedated. A baseline assessment of conventional ventilation (assist control) and positive end-expiratory pressure (PEEP) of 5cm H2O was initiated. Ventilator mode was changed to APRV with incremental elevations of CPAP-high from 10 to 35cm H2O. After a 3-to-5-minute stabilization period, measurements of hemodynamic parameters (PCWP, LAP, and CVP) were recorded at each level of APRV pressure settings. Results. Increasing CPAP caused increased PCWP and LAP measurements above their baseline values. Mean PCWP and LAP were linearly related (LAP = 0.66()PCWP + 4.5cm H2O, R 2 = 0.674, and P