Pre-treatment with sevoflurane attenuates direct lung injury

Background: Sevoflurane exerts effects on pulmonary cells that could protect against lung injury. We evaluated the potential of pretreatment with sevoflurane to attenuate lipopolysaccharide (LPS)-induced lung injury. Methods: LPS was administered intratracheally in Wistar rats to induce lung injury. Sevoflurane was administered for 30 min at 0.25, 0.5 or 1.0 MAC 15 min before LPS or for 30min at 0.5 MAC 24 hours before LPS. After initial analysis of bronchoalveolar lavage fluid (BALF) cells and total protein, the group of 0.5 MAC 15min before LPS was further analyzed for surfactant aggregates subfractions, plasma malondialdehyde levels and lung histology. Results: LPS instillation resulted in neutrophils sequestration in the lungs, loss of alveolar macrophages, increased BALF total protein and decreased large surfactant aggregates. Only inhalation of sevoflurane for 30min at 0.5 MAC 15min before LPS installation effectively reduced neutrophil accumulation, preserved alveolar epithelial cells and reduced total protein content in BALF. This regimen also reduced plasma malondialdehyde levels and increased large surfactant aggregates, despite the application of mechanical ventilation. This effect was preserved after LPS instillation and the favorable composition of surfactant was maintained. Conclusions: Pretreatment with sevoflurane effectively attenuates direct severe lung injury, possibly by inhibition of neutrophil accumulation and alteration of the surfactant composition