Effects of Positive End-Expiratory Pressure on the Risk of Postoperative Pulmonary Complications in Patients Undergoing Elective Craniotomy.

BACKGROUND:Intraoperative use of positive end-expiratory pressure (PEEP) has a protective effect in patients with acute lung injury and is recommended during anesthesia to minimize postoperative pulmonary complications. However, high levels of pressure might also cause harm to the lung because of overdistension. This retrospective study was designed to compare the effect of low and high levels of PEEP on the risk of postoperative pulmonary complications in patients with normal lung function who were undergoing an elective craniotomy. METHODS:Two thousand four hundred thirty-seven patients without any pre-existing respiratory disease, who underwent an elective craniotomy, were hospitalized from January 1, 2008, to December 31, 2012. The patients were divided into 2 groups according to the application of an intraoperative PEEP < 5 or ≥ 5 cm H2O, referred as low and high groups. Primary outcome was the odds of postoperative pneumonia and the requirement for either noninvasive ventilation (NIV) or reintubation and mechanical ventilation (MV). RESULTS:One thousand twenty-three (42%) of 2437 patients were in the low group, and 1414 patients (58%) were in the high group. Patients in the low group did not show any difference in the incidence of postoperative pneumonia (P = 0.523) or the requirement of postoperative reintubation and MV (P = 0.999) compared with those in the high group. The incidence of reintubation and MV is significantly associated with postoperative pneumonia (P < 0.001). CONCLUSIONS:Low and high levels of PEEP show similar incidences of postoperative pneumonia and requirement of postoperative NIV or invasive MV in patients with normal function of the lungs undergoing elective craniotomy.