Effects of high‐frequency oscillatory ventilation (HFOV) and inhaled nitric oxide (iNO) against oxidative lung injury in a rabbit model of acute lung injury (ALI)

Abstract

Mechanical ventilation (MV) can induce lung injury. Oxidative damage has been said to play an important role in pulmonary injury which is associated with acute respiratory distress syndrome (ARDS) development and progression. To compare protective conventional mechanical ventilation (CMV) and HFOV associated with/without iNO for lung oxidative stress, DNA damage, total antioxidant performance and nitric oxide (NO) concentration were determined in an animal model. Lung injury was induced by tracheal infusion of warm saline. Fifty rabbits (male, Norfolk white) were randomly assigned to: a) Sham Control (CG): without ALI + CMV; b) ALI + CMV (MVG); c) ALI + CMV with iNO (MVGNO); d) ALI + HFOV (HFG) and e) ALI + HFOV with iNO (HFGNO). Lung oxidative stress was assessed in the lung tissue and plasma by total antioxidant performance (TAP) assay using fluorometry, DNA damage by single cell gel electrophoresis (comet assay) in the lung tissue, and NO concentration in the plasma by a fluorometric assay. After 4 hours of MV, HFOV groups and CMV associated with iNO had a significant reduction in the lung oxidative stress and DNA damage compared to CMV (p< 0.05). There was no significant difference in plasma NO concentration among groups (p > 0.05). HFOV and iNO showed a protective effect against oxidative lung injury in saline-lavaged rabbit model of ALI. [Supported by FAPESP: 2008/08199-2, USDA 58-1950-7-07]