Study objective: The present study was carried out to evaluate the prognostic value of pulmonary fibrosis diagnosed on the basis of pulmonary samples obtained by fiberscopic transbronchial lung biopsy (TBLB) in patients treated for severe established adult respiratory distress syndrome (ARDS).
Design: Prospective cohort study.
Setting: Intensive Care Unit of a University Hospital.
Patients: Consecutive patients with a diagnosis of established ARDS.
Interventions: Samples of pulmonary tissue (3 to 6 in each patient) were obtained by fiberoptic TBLB. Severity of pulmonary fibrosis was assessed based on pathologic changes. Hematoxylin and eosin and Masson's trichrome stains were performed on each tissue sample.
Main results: Twenty-two lung specimens were obtained from 25 consecutive patients with ARDS of various origin (postsurgical complications, 7 patients; multiple trauma, 8 patients; medical problems, 7 patients). Transbronchial lung biopsy was complicated by small or moderate hemorrhage in three patients. No case of pneumothorax was identified. Pathologic findings showed that 14 patients (64%) had pulmonary fibrosis, either mild (9 patients) or moderate to severe fibrosis (5 patients). In the patients with pulmonary fibrosis, mortality rate was 57% (8 out of 14 patients), which was significantly different (p < 0.02) from the 0% mortality rate observed in patients without pulmonary fibrosis. Severity of pulmonary fibrosis (mild vs moderate and severe) did not influence outcome. With the exception of pathologic findings, characteristics of patients with and without pulmonary fibrosis (PaO2, PaCO2, the ratio of PaO2 to fraction of inspired oxygen, and positive end-expiratory pressure) were not different.
Conclusion: In the study patients, pulmonary fibrosis diagnosed on the basis of TBLB was closely related to fatality in established ARDS.