Pressão expiratória final positiva durante a anestesia geral para a prevenção da mortalidade pós-operatória

Abstract

General anasthesia causes atelectasis, which can lead to impaired respiratory function. Positive end-expiratory pressure (peep) is a mechanical manoeuvre that increases functional residual capacity and prevents collapse of the airways, thereby reducing atelectasis. It is not known whether intraoperative peep alters the risks of postoperative mortality. The objective of this research was to evaluate the benefits and harms of intraoperative peep in terms of postoperative mortality in patients with 16 years old and over. The cochrane central register of controlled trials (central) 2013, issue 10, medline (via ovid) from 1966 to october 2013, embase (via ovid) from 1980 to october 2013, cinahl (via ebscohost) from 1982 to october 2013, isi web of science from 1945 to october 2013 and lilacs (via bireme interface) from 1982 to october 2013 were searched. Two review authors independently selected papers, assessed trial quality and extracted data from randomized clinical trials assessing the effects of peep versus no peep during general anesthesia on postoperative mortality and postoperative respiratory complications in patients with 16 years of age and older. In total, 10 randomized trials with 432 participants and four comparisons are included in this review. One trial was classified as low risk of bias. No differences were demonstrated in mortality, with relative risk reduction 0,05 with 95% confidence interval (ci 95%) - 0,04 to 0,04 and pneumonia, with relative risk (rr) of 0.40 (95% ci 0.11 to 1.39). The peep group had higher arterial oxygen pressure/fraction of inspired oxygen on day one postoperatively, with a mean difference of 22.98 (95% ci 4.40 to 41.55) and lower postoperative atelectasis, with standard mean difference -1.2 (95% ci - 1.78 to - 0.79). Evidence is currently insufficient to permit conclusions about whether intraoperative peep alters risks of postoperative mortality among surgical patients.