Intra-operative ventilator mechanical power as a predictor of postoperative pulmonary complications in surgical patients: A secondary analysis of a randomised clinical trial

BACKGROUND Studies in critically ill patients suggest a relationship between mechanical power (an index of the energy delivered by the ventilator, which includes driving pressure, respiratory rate, tidal volume and inspiratory pressure) and complications. OBJECTIVE We aimed to assess the association between intra-operative mechanical power and postoperative pulmonary complications (PPCs). DESIGN Post hoc analysis of a large randomised clinical trial. SETTING University-affiliated academic tertiary hospital in Melbourne, Australia, from February 2015 to February 2019. PATIENTS Adult patients undergoing major noncardiothoracic, nonintracranial surgery. INTERVENTION Dynamic mechanical power was calculated using the power equation adjusted by the respiratory system compliance (CRS). Multivariable models were used to assess the independent association between mechanical power and outcomes. MAIN OUTCOME MEASURES The primary outcome was the incidence of PPCs within the first seven postoperative days. The secondary outcome was the incidence of acute respiratory failure. RESULTS We studied 1156 patients (median age [IQR]: 64 [55 to 72] years, 59.5% men). Median mechanical power adjusted by CRS was 0.32 [0.22 to 0.51] (J min−1)/(ml cmH2O−1). A higher mechanical power was also independently associated with increased risk of PPCs [odds ratio (OR 1.34, 95% CI, 1.17 to 1.52); P 
Source: European Journal of Anaesthesiology - Category: Anesthesiology Tags: ICU Source Type: research