Background: Surfactant therapy may be useful for treating acute lung injury (ALI). Aerosolized surfactant for treatment of ALI has not been investigated.
Aim: Evaluate aerosolized surfactant (KL4; lucinactant, Discovery Laboratories, Inc., Warrington, PA) in treating piglets with HCl-induced ALI.
Methods: ALI was induced in spontaneously breathing piglets with intratracheal 0.2N HCl until PaO2 was ≤350 torr at FiO2 1.0. Piglets were randomized to receive 175mg/kg endotracheal KL4 (ET KL4) with extubation to CPAP; aerosolized KL4 (AERO KL4) for 60 minutes at 22.5mg/min while on CPAP; or CPAP alone (control/CPAP). Piglets were monitored for 3 hours. Blood gases were obtained every 30 minutes. Lung tissue was analyzed for IL-8 and total protein by porcine-specific ELISA and Bradford with group differences analyzed by ANOVA. Physiologic data were analyzed using 2-way ANOVA with Tukey LSD post-hoc testing for p-values < 0.05.
Results: Both ET KL4 and AERO KL4 produced higher PaO2s (p< 0.001) and improved survival (p< 0.05) compared to CPAP controls. AERO KL4 was as effective as ET KL4, and produced the highest final PaO2 (p< 0.05). IL-8/total protein ratios were lower in AERO KL4 versus CPAP controls (p< 0.03).
Conclusions: In spontaneously breathing piglets with ALI, AERO KL4 was as effective as ET KL4 and produced the highest final PaO2. AERO KL4 treated piglets had lower IL-8/total protein ratios suggesting less lung inflammation. This is the first successful use of aerosolized surfactant in an animal model of ALI.