Atelectasis and perioperative pulmonary complications in high-risk patients

Abstract

This review evaluates the link between perioperative lung atelectasis and postoperative pulmonary complications (PPCs) and how appropriate ventilatory strategies could mitigate this problem. Atelectasis may contribute to serious PPCs including respiratory failure and pneumonia. Ventilator settings during anesthesia, especially with higher tidal volumes (V(T)) (>10 ml/kg), high plateau pressures (>30 cmH(2)O) and without positive end expiratory pressure (PEEP), are associated with lung injury even in healthy, but partially collapsed, lungs. These injurious settings may cause inflammation which is related to repetitive tidal recruitment and alveolar overdistension. Such ventilator-induced lung injury can be attenuated by using low V(T) and plateau pressures at sufficient PEEP, ideally after actively recruiting the lungs. The use of continuous positive airway pressure and 'lower' FiO(2) during anesthetic induction, intraoperative use of lower FiO(2), low V(T), lung recruitment and PEEP ('protective ventilatory strategy') in conjunction with postoperative early mobilization, breathing exercises and continuous positive airway pressure may help in maintaining lung aeration, thereby decreasing hypoxemia and risk of postoperative pneumonia. Evidence is accumulating suggesting that the incidence of postoperative pulmonary complication could be markedly reduced if an 'open lung' philosophy was adopted for the perioperative care. A goal-directed ventilatory approach keeping an 'open lung' condition during the perioperative period may reduce the incidence of PPCs.