Mechanical ventilation in cardiac surgery

Postoperative pulmonary dysfunction (PPD) is a frequent complication after cardiac surgery. Its pathogenesis is related to pulmonary inflammation, but this appears to be secondary to multiple etiological factors, including the surgical procedure itself, extra corporeal circulation (ECC), ischemia-reperfusion injury, and mechanical ventilation (MV). On the other hand, the presence of atelectasis remains one of the principal causes of PPD. The open lung approach (OLA) is a protective ventilation strategy, typically initiated after orotracheal intubation and maintained until extubation of the patient. Compared to a conventional ventilation strategy, OLA improves gas exchange parameters, induces a minor elevation of inflammatory mediators, and retains more residual functional capacity. Finally, recent studies have shown that the addition of low frequency ventilation during ECC can decrease the incidence of PPD after cardiac surgery.