OBJECTIVE The aim of this study was to assess the feasibility and safety of noninvasive positive-pressure ventilation (NPPV) via a face mask to aid in performing fiberoptic bronchoscopy (FOB) with BAL in immunosuppressed patients with gas exchange abnormalities that contraindicate using conventional unassisted FOB. METHODS Eight consecutive immunosuppressed patients (40 +/- 14 years old) with suspected pneumonia entered the study. Entrance criteria included the following: (1) PaO2/fraction of inspired oxygen (FIo2) of 100 or less; pH of 7.35 or more; and (3) improvement in O2 saturation during NPPV before initiating FOB. METHODS Patients had routine application of topical anesthesia to the nasopharynx. A full face mask was connected to a ventilator (Servo 900C; Solna, Sweden) set to deliver continuous positive airway pressure (CPAP) of 4 cm H2O, pressure support ventilation of 17 cm H2O, and 1.0 FIo2. The mask was secured to the patient with head straps. NPPV began 10 min before starting FOB and continued for 90 min or more after the procedure was completed. The bronchoscope was passed through a T-adapter and advanced through the nose. BAL was obtained by sequential instillation and aspiration of 5 to 25 mL aliquots of sterile saline solution through a bronchoscope wedged in a radiographically involved subsegment. Oxygen saturation, heart rate, respiratory rate, and arterial blood gases were monitored during the study. RESULTS NPPV significantly improved PaO2/FIo2 and O2 saturation. FOB with NPPV was well tolerated, and no patient required endotracheal intubation. A causative pathogen was identified by BAL in all patients. Six patients responded to treatment and survived hospital admission. Two patients died 5 to 7 days after FOB from unrelated complications of the underlying illness. CONCLUSIONS NPPV should be considered during bronchoscopy of immunosuppressed patients with severe hypoxemia.