Effect of Bronchoalveolar Lavage on Gas Exchange in Patients with Diffuse Lung Disease and Respiratory Failure

Abstract

The effect of fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) on arterial oxygenation was examined in 22 patients with acute respiratory failure requiring mechanical ventilatory support. Arterial blood gases were determined immediately prior to BAL and at 15, 60, 120, and 360 minutes following BAL. PaO₂/FIO₂ decreased at 15 minutes and continued to decrease to approximately 33% below the baseline value at 2 hours. PaO₂/FIO₂ then remained constant over the remainder of the 6-hour study period. No substantial changes in FIO₂, level of positive end-expiratory pressure, or intravenous pressor requirements occurred during the period of observation. Patients with lower pre-BAL PaO₂/FIO₂ ratios showed the least reduction in PaO₂/FiO₂ following BAL The BAL was diagnostic in 9 of 22 (41%) patients (Pneumocystis carinii pneumonia in 5, bacterial pneumonitis in 2, and neoplastic involvement of the lung in 2). BAL was associated with mild deterioration of gas exchange but did not require significant changes in ventilatory or hemodynamic support for the 6-hour interval studied.