Nebulized Heparin for Adult Patients With Smoke Inhalation Injury: A Review of the Literature

Objective: To review the clinical effects of nebulized heparin and N-acetylcysteine (NAC) in patients with smoke inhalation injury (IHI) and provide recommendations for use. Data Sources: A search of PubMed, MEDLINE, and Scopus databases was completed from database inception through April 15, 2020, using terms: heparin, acetylcysteine, smoke inhalation injury, and burn injury. Study Selection and Data Extraction: All studies pertaining to efficacy and safety of nebulized heparin and/or NAC for IHI in adult patients were evaluated. Reference lists were reviewed for additional publications. Nonhuman studies, non-English, and case report publications were excluded. Data Synthesis: Eight studies were included. Four demonstrated positive outcomes, 3 demonstrated no benefit or possible harm, and 1 assessed safety. Supporting trials treated patients within 48 hours of injury with 10 000 units of nebulized heparin with NAC for 7 days or until extubation. Two trials with negative findings treated patients within 72 hours, or unspecified, with 5000 units of nebulized heparin with NAC for 7 days, while the third used 25 000 units within 36 hours but was grossly underpowered for analysis. Clinical findings include reduced duration of mechanical ventilation and improved lung function with possible increase risk of pneumonia and no evidence of increased bleeding risk. Conclusions: Nebulized heparin may improve oxygenation and reduce duration of mechanical ventilation in IHI. If nebulized heparin is used, 10 000 units every 4 hours alternating with NAC and albuterol at 4-hour intervals is recommended. Sterile technique should be emphasized. Monitoring for bronchospasm or new-onset pneumonia should be considered.