Aerosolized KL₄ surfactant improves short-term survival and gas exchange in spontaneously breathing newborn pigs with hydrochloric acid-induced acute lung injury

Summary Background Surfactant therapy may be beneficial in acute lung injury (ALI). In spontaneously breathing newborn pigs with ALI supported with continuous positive airway pressure (CPAP), we evaluated the hypothesis that aerosolized KL₄ surfactant (AERO KL₄S) would provide a similar therapeutic effect as intratracheal KL₄ surfactant (ETT KL₄S) when compared to controls. Methods We randomized pigs with HCl-induced ALI to: (1) 175mg/kg KL₄ surfactant via endotracheal tube (ETT); (2) AERO KL₄S (22.5mg/min phospholipid) for 60min via continuous positive airway pressure (CPAP); or (3) sham procedure on CPAP. We obtained physiologic data and arterial blood gases throughout the 3-hr study. At study end, lungs were excised for analysis of interleukin-8 (IL-8), myeloperoxidase (MPO) levels and histomorphometric data. Results Pigs treated with ETT KL₄S and AERO KL₄S had improved survival and sustained pO₂ compared to controls. The AERO KL₄S group had higher pH compared to controls. Lung IL-8 levels were lower in the AERO KL₄S group compared to controls. Histomorphometric analysis showed less hemorrhage in the ETT and AERO KL₄S groups compared to controls. The AERO KL₄S group had more open lung units per fixed-field than the ETT KL₄S or controls. Conclusions AERO KL₄S produced similar improvements in survival, physiology, inflammatory markers, and morphology as ETT KL₄S in an ALI model.