A Multicenter Evaluation of Outcomes Following the Use of Nebulized Heparin for Inhalation Injury (HIHI2 Study).

ABSTRACT

Inhalation injury causes significant morbidity and mortality secondary to compromise of the respiratory system as well as systemic effects limiting perfusion and oxygenation. Nebulized heparin reduces fibrin cast formation and duration of mechanical ventilation in patients with inhalation injury. To date, no study has compared both dosing strategies of 5000 and 10,000 units to a matched control group. This multicenter, retrospective, case-control study included adult patients with bronchoscopy-confirmed inhalation injury. Each control patient, matched according to age and percent of total body surface area, was matched to a patient who received 5000 units and a patient who received 10,000 units of nebulized heparin. The primary endpoint of the study was duration of mechanical ventilation. Secondary endpoints included 28-day mortality, ventilator-free days in the first 28 days, difference in lung injury scores, length of hospitalization, incidence of ventilator-associated pneumonia, and rate of major bleeding. Thirty-five matched patient trios met inclusion criteria. Groups were well-matched for age (P = .975) and total body surface area (P = .855). Patients who received nebulized heparin, either 5000 or 10,000 units, had 8 to 11 less days on the ventilator compared to controls (P = .001). Mortality ranged from 3 to 14% overall and was not statistically significant between groups. No major bleeding events related to nebulized heparin were reported. Mechanical ventilation days were significantly decreased in patients who received 5000 or 10,000 units of nebulized heparin. Nebulized heparin, either 5000 units or 10,000 units, is a safe and effective treatment for inhalation injury.