Lung-Protective Effects of Lidocaine Infusion on Patients with Intermediate/ High Risk of Postoperative Pulmonary Complications: A Double-Blind Randomized Controlled Trial

Purpose: The non-local anesthetic effects of lidocaine have been widely reported, but there are still few studies on lung protection. We aimed to test the hypothesis that intravenous infusion of lidocaine exerts lung-protective effects in patients at intermediate/high risk of postoperative pulmonary complications (PPCs) on major abdominal surgery. Patients and Methods: Patients ≥ 18 years, ASA II or III, with intermediate/high risk for PPCs, were included. Patients were randomly assigned into group lidocaine (received a bolus of lidocaine 1.5 mg kg − 1 before the induction of anesthesia, then followed by a continuous infusion of 2.0 mg kg − 1 h − 1 intraoperatively until the end of surgery) or group control (received 0.9% saline in place of lidocaine at the same time points). The incidence of PPCs within 7 postoperative days was measured, defined as a collapsed composite outcome of atelectasis, respiratory infection, pleural effusion, pneumonia, respiratory failure or acute respiratory distress syndrome (ARDS) developed within 7 postoperative days, or hospital discharge, whichever came sooner. Results: Of 200 subjects screened, 195 patients were finally analyzed. Overall, 35.9% (70/195) patients sustained PPCs, which occurred fewer in group lidocaine 25.8% (25/97), compared with group control 45.9% (45/98) (relative risk: 0.56, 95% CI: 0.38 to 0.84; absolute risk reduction: − 20.1%; P = 0.003). Considering single PPCs episode, the most common PPC in both groups was atelectasis. The atelectasis incidence was 11.3% (11/97) in group lidocaine, much lower than that in group control 29.6% (29/98) (relative risk: 0.38, 95% CI: 0.20 to 0.72; absolute risk reduction: − 18.3%, P = 0.002). However, the incidences of any other PPCs episodes were similar between the two groups. Conclusion: Intraoperative intravenous infusion lidocaine could decrease the incidence of PPCs in patients at intermediate/high risk of postoperative pulmonary complications undergoing major abdominal surgery. Keywords: postoperative pulmonary complications, lidocaine, lung injury, pulmonary protection