Comparison of prone positioning and continuous rotation of patients with adult respiratory distress syndrome:: Results of a pilot study

Objective: To compare prone positioning and continuous rotational therapy with respect to oxygenation and hemodynamics in patients suffering from adult respiratory distress syndrome (ARDS). Design: Randomized, prospective pilot study. Setting: Intensive care unit at a university hospital. Patients: Twenty-six mechanically ventilated patients with ARDS from nontraumatic causes. Interventions: Twelve patients were turned prone (group 1), 14 patients underwent continuous axial rotation from one lateral position to the other with a maximum angle of 124 degrees in specially designed beds (group 2). All patients had received inhaled nitric oxide (NO) therapy before positioning. Measurements and Main Results: Gas exchange and hemodynamics were assessed using a pulmonary artery catheter. In both groups, an improvement in PaO2/FIO2-ratio and intrapulmonary shunt fraction occurred after initiation of NO as well as during the first 72 hrs of positioning therapy. During the study period, seven patients died in group 1 and nine patients in group 2 (p = NS). comparing the areas under the curve during the first 72 hrs, no significant differences with respect to PaO2/FIO2-ratio, PaCO2, positive end-expiratory and peak inspiratory pressure levels, intrapulmonary shunt fraction, the alveolar-arterial oxygen difference, and oxygen delivery and consumption, as well as cardiac index, pulmonary and arterial blood pressures, and pulmonary arterial occlusion pressure could be detected between the groups. Prone positioning was tolerated well, continuous rotational therapy had to be modified according to hemodynamic instability in three patients. Conclusions: In severe lung injury, continuous rotational therapy seems to exert effects comparable to prone positioning and could serve as alternative when prone positioning seems inadvisable.