Low tidal volume ventilation with low PEEP during surgery may induce lung inflammation

BACKGROUND Compared to conventional tidal volume ventilation, low tidal-volume ventilation reduces mortality in cased of acute respiratory distress syndrome. The aim of the present study is to determine whether low tidal-volume ventilation reduces the production of inflammatory mediators in the lungs and improves physiological status during hepatic surgery. METHODS We randomly assigned patients undergoing hepatectomy into 2 groups: conventional tidal-volume vs. low tidal-volume (12 vs. 6 mL•kg(-1) ideal body weight) ventilation with a positive end-expiratory pressure of 3 cm H2O. Arterial blood and airway epithelial lining fluid were sampled immediately after intubation and every 3 h thereafter. RESULTS Twenty-five patients were analyzed. No significant changes were found in hemodynamics or acid-base status during the study. Interleukin-8 was significantly elevated in epithelial lining fluid from the low tidal-volume group. Oxygenation evaluated immediately after admission to the post-surgical care unit was significantly worse in the low tidal-volume group. CONCLUSIONS Low tidal-volume ventilation with low positive end-expiratory pressure may lead to pulmonary inflammation during major surgery such as hepatectomy. TRIAL REGISTRATION The effect of ventilatory tidal volume on lung injury during hepatectomy that requires transient liver blood flow interruption. UMIN000021371 (03/07/2016); retrospectively registered.