Lateral positioning of ventilated intensive care patients: A study of oxygenation, respiratory mechanics, hemodynamics, and adverse events

Abstract

To investigate the effect of 90 degrees lateral positioning on oxygenation, respiratory mechanics, and hemodynamics in ventilated intensive care patients. Thirty-four subjects (mean age = 46.1 +/- 17.3 years) with no, unilateral, or bilateral pulmonary infiltrates on chest radiograph participated. Arterial blood gas, respiratory mechanic, and hemodynamic data were analyzed at the supine starting position (T0), then 30 minutes and 2 hours into the lateral turn (T30 and T120, respectively) and 30 minutes post return to the supine position (T150). No difference was found in PaO(2)/FiO(2) due to positioning patients from supine to lateral (P = .15) regardless of the underlying lung pathology. Dynamic compliance decreased during lateral positioning, particularly in the subjects with no lung pathology (T0 = 56 +/- 18.6 > (T30 = 49.9 +/- 18; T120 = 49.2 +/- 17) L/cmH(2)0, P < .01) or unilateral lung pathology (T0 = 41.4 +/- 11.2 > (T30 = 36.6 +/- 8.8; T120 = 37.3 +/- 9.5) L/cmH(2)0, P < .01). Blood pressure and heart rate were unaffected, but cardiac index significantly increased at T30 (T0 = 3.7 +/- 1.2, T30 = 4.8 +/- 1.3 L/min/m(2), P < .01). While the incidence of adverse events was high (21%), they were primarily minor and transient. In this heterogeneous population, lateral positioning had no beneficial effect on gas exchange. However, in ventilated patients who were hemodynamically stable, it was well tolerated and not associated with significant serious adverse events.