RESULTS. 15% of patients had solid tumors and 85% had hematological malignancies. There were 36.1% neutropenic patients and 25% hematopoietic stem-cell transplant recipients. Treatments at ICU admission included antibacterial (80%), antifungal (29%), and antiviral (15%) agents. We found no significant differences regarding the need for MV (35.4 and 38.7% of patients in the invasive and noninvasive groups, respectively), proportion of patients with no diagnosis (20.4 vs. 21.7%), or 28-day mortality (29 vs. 33%). In the invasivestrategy group, the cause of ARF was identified by FO-BAL (performed within 1 (0-1) day after ICU admission) only in 18% of patients and by noninvasive tests only in 45% of patients (P \ 0.0001).