Recovery from lung injury in survivors of acute respiratory distress syndrome: Difference between pulmonary and extrapulmonary subtypes

Abstract

Objective: To determine whether long-term outcome differs between acute respiratory distress syndrome (ARDS) resulting from pulmonary (ARDSp) and extrapulmonary (ARDSexp) causes. Design: Observational study. Setting: Medical intensive care unit of a university hospital. Patients: Twenty-nine ARDS patients (16 ARDSp and 13 ARDSexp) who survived over 6 months after diagnosis. Measurements and results: The two groups did not differ according to demographic data and severity indices on admission. The duration of ICU stay (median 21 days [interquartile range, 12-43 days] vs 12 [6.5-20] days, p=0.097) tended to be longer and total ventilation time (360 [96-700] h vs 144 [42.5-216] h, p=0.045) were longer in the patients with ARDSp. The ARDSp patients showed more severe abnormalities on thin-section computed tomography (CT), including ground-glass opacity (GGO; 6 [3-16] vs 0 [0-2.5], p=0.002), reticular density (12 [8-14] vs 5 [2-9], p=0.033) and the sum of all four patterns of lesion (20 [11-27] vs 5 [2-12], p=0.006). There were no between-group differences in Spitzer's Quality of Life index and the Chronic Respiratory Questionnaire. Conclusions: These results suggest that ARDSp would leave more severe lung sequelae than ARDSexp, but the clinical relevance of their difference is questionable.