Protective lung ventilation during general anesthesia: is there any evidence?

In acute respiratory distress syndrome (ARDS) several studies have shown that mechanical ventilation with high tidal volume (VT) and low levels of positive end-expiratory pressure (PEEP) can promote ventilator-induced lung injury (VILI), thus increasing morbidity and mortality [1]. An open lung strategy, combining the use of low VT with adequate PEEP levels and recruitment maneuvers, has thus been recommended in ARDS patients [2–4]. In patients without ARDS admitted to intensive care units (ICUs), who required mechanical ventilation for at least 12 hours, the use of a high VT significantly increased the inflammatory response [5, 6]. In contrast to critically ill patients, during general anesthesia, mechanical ventilation is required only for a few hours, thus the beneficial effects of lung-protective ventilation remain questionable. Moreover, there are limited data from few randomized controlled trials with only small cohorts of enrolled patients.