Scheduled Bronchoscopy with Nebulized Heparin and N-Acetylcysteine in Burn Patients with Inhalation Injury: A...

Inhalation injury (II) exacerbates burn mortality via obstructive fibrin casts. We evaluated a protocol combining scheduled flexible bronchoscopy (FOB) with nebulized heparin and N-acetylcysteine (NAC). This single-center, randomized controlled trial enrolled 76 mechanically ventilated adult burn patients with bronchoscopically confirmed II. The intervention (n = 38) comprised a 7-day protocol of scheduled FOB with alternating nebulized heparin (5000 IU) and 20% NAC every 4 h. Controls (n = 38) received standard care with on-demand FOB. Primary outcomes were 28-day mortality and day-7 Lung Injury Score (LIS). Unadjusted 28-day mortality was lower in the intervention group (57.9% vs. 81.6%; p = 0.025), alongside a decreased median day-7 LIS (1.0 vs. 1.38; p = 0.021). Respiratory mechanics improved significantly, demonstrating reduced driving pressure and increased static compliance (p < 0.001). However, in multivariable Cox regression, baseline injury severity independently predicted mortality, while the intervention indicated a non-significant hazard reduction trend (aHR = 0.66, 95% CI: 0.36-1.23). No systemic anticoagulation occurred. In conclusion, scheduled FOB with nebulized heparin and NAC improves respiratory mechanics and attenuates lung injury in II. Although unadjusted mortality decreased, baseline severity remains the primary mortality driver, suggesting this protocol is a physiologically beneficial adjunct requiring further multicenter validation. Trial registration: Thai Clinical Trials Registry, TCTR20260408001 (retrospectively registered).