A Randomized Control Trial Comparing the Yield of Bronchoalveolar Lavage Using Three Different Techniques in Patients Undergoing Flexible Bronchoscopy (BAL-3T)

Background: Three techniques have been described for aspirating the bronchoalveolar lavage (BAL) fluid, namely the wall mount suction (WMS), manual suction (MS), and manual suction with tubing (MST). However, there is no direct comparison among the 3 methods.

Methods: We randomized patients undergoing flexible bronchoscopy and BAL in a 1:1:1 ratio to one of the 3 arms. The primary outcome was to compare the optimal yield, defined as at least 30% return of volume instilled and <5% bronchial cells. The key secondary outcomes were the percentage of volume and total amount (in millimeters) return of BAL, as well as complications (hypoxemia, airway bleeding, and others).

Results: We randomized 942 patients [MST (n = 314), MS (n = 314), WMS (n = 314)]. The mean age of the study population [58.7% (n = 553) males] was 46.9 years. The most common indication for BAL was suspected pulmonary infection. Right upper lobes and middle lobes were the commonest sampled lobes. The optimal yield was similar in all the groups [MST (35.6%) vs MS (42.2%) vs WMS (36.5%); P = 0.27]. A significantly higher proportion of patients had BALF return >30% (P = 0.005) in the WMS (54.2%) and MS (54%) than in the MST arm (42.9%). The absolute and the percentage volume of BALF was also higher in WMS and MS than in the MST arm. There was no difference in the complication rate or other secondary outcomes across the groups.

Conclusion: We found no difference in the optimal yield of BAL or complications using any one of the 3 methods for BAL fluid retrieval.