Prone position as prevention of lung injury in comatose patients: a prospective, randomized, controlled study

Objective: Comatose patients frequently exhibit pulmonary function worsening, especially in cases of pulmonary infection. It appears to have a deleterious effect on neurologic outcome. We therefore conducted a randomized trial to determine whether daily prone positioning would prevent lung worsening in these patients. Design: Prospective, randomized, controlled study. Setting: Sixteen-bed intensive care unit. Patients: Fifty-one patients who required invasive mechanical ventilation because of coma with Glascow coma scores of 9 or less. Interventions: In the prone position (PP) group: prone positioning for 4 h once daily until the patients could get up to sit in an armchair; in the supine position (SP) group: supine positioning. Measurements and results: The primary end point was the incidence of lung worsening defined by an increase in the Lung Injury Score of at least I point since the time of randomization. The secondary end point was the incidence of ventilator-associated pneumonia (VAP). A total of 25 patients were randomly assigned to the PP group and 26 patients to the SP group. The characteristics of the patients from the two groups were similar at randomization. The incidence of lung worsening was lower in the PP group (12%) than in the SP group (50%) (p=0.003). The incidence of VAP was 20% in the PP group and 38.4% in the SP group (p=0.14). There was no serious complication attributable to prone positioning, however, there was a significant increase of intracranial pressure in the PP. Conclusion: In a selected population of comatose ventilated patients, daily prone positioning reduced the incidence of lung worsening.