Airway pressure release ventilation increases cardiac performance in patients with acute lung injury/adult respiratory distress syndrome

Background The purpose of the present study is to determine whether airway pressure release ventilation (APRV) can safely enhance hemodynamics in pati ents with acute lung injury (ALI) and/or adult respiratory distress syndrom e (ARDS), relative to pressure control ventilation (PCV). Methods Patients with severe acute lung injury or ARDS who were managed wit h inverse-ratio pressure control ventilation, neuromuscular blockade and a pulmonary artery catheter were switched to APRV. Hemodynamic performance, a s well as pressor and sedative needs, was assessed after discontinuing neur omuscular blockade Results Mean age was 58 +/- 9 years (n = 12) and mean Lung Injury Score was 7.6 +/- 2.1. Temperature and arterial oxygen tension/fractional inspired o xygen (FiO(2)) were similar among the patients. Peak airway pressures fell from 38 +/- 3 for PCV to 25 +/- 3 cmH(2)O for APRV, and mean pressures fell from 18 +/- 3 for PCV to 12 +/- 2 cmH(2)O for APRV. Paralytic use and seda tive use were significantly lower with APRV than with PCV. Pressor use decr eased substantially with ARPV. Lactate levels remained normal, but decrease d on APRV. Cardiac index rose from 3.2 +/- 0.4 for PCV to 4.6 +/- 0.3 l/min per m(2) body surface area (BSA) for APRV, whereas oxygen delivery increas ed from 997 +/- 108 for PCV to 1409 +/- 146 ml/min for APRV, and central ve nous pressure declined from 18 +/- 4 for PCV to 12 +/- 4 cmH(2)O for APRV. Urine output increased from 0.83 +/- 0.1 for PCV to 0.96 +/- 0.12 ml/kg per hour for APRV. Conclusion APRV may be used safely in patients with ALI/ARDS, and decreases the need for paralysis and sedation as compared with PCV-inverse ratio ven tilation (IRV). APRV increases cardiac performance, with decreased pressor use and decreased airway pressure, in patients with ALI/ARDS.