The relation of pneumothorax and other air leaks to mortality in the acute respiratory distress syndrome

Background In patients with the acute respiratory distress syndrome, pneumothorax and other air leaks - any extrusion of air outside the tracheobronchial tree - have been attributed to high ventilatory pressures or volumes and linked to increased mortality. Methods We analyzed data from a prospective trial of aerosolized synthetic surfactant in 725 patients with the acute respiratory distress syndrome induced by sepsis. We compared the ventilatory pressures and volumes in the patients without any air leaks (the highest values during the five-day study) with the pressures and volumes in those with pneumothorax or with any air leaks (the highest values during the 16- and 24-hour periods before the complication developed). Results Fifty patients (6.9 percent) had pneumothorax, and 77 (10.6 percent) had pneumothorax or other air leaks. There were no significant differences between patients with air leaks and those without air leaks in any pressure or volume examined. Overall mortality at 30 days was 40.0 percent (95 percent confidence interval, 36.4 to 43.6); among the patients with pneumothorax, it was 46.0 percent (95 percent confidence interval, 32.2 to 59.8), and among those without pneumothorax, it was 39.3 percent (95 percent confidence interval, 35.6 to 43.0; P=0.35). The mortality rate was 45.5 percent (95 percent confidence interval, 34.4 to 56.6) in the group with any air leaks and 39.0 percent (95 percent confidence interval, 35.3 to 42.8) in the group without air leaks (P=0.28). Conclusions In patients with sepsis-induced acute respiratory distress syndrome who were receiving mechanical ventilation with conventional pressures and volumes, there were no significant correlations between high ventilatory pressures or volumes and the development of pneumothorax or other air leaks. Pneumothorax or other air leaks were not associated with a significantly increased mortality rate. (C) 1998, Massachusetts Medical Society.