Limb Remote Ischemic Preconditioning Attenuates Lung Injury after Pulmonary Resection under Propofol-Remifentanil Anesthesia A Randomized Controlled Study

Background: Remote ischemic preconditioning (RIPC) may confer the protection in critical organs. The authors hypothesized that limb RIPC would reduce lung injury in patients undergoing pulmonary resection. Methods: In a randomized, prospective, parallel, controlled trial, 216 patients undergoing elective thoracic pulmonary resection under one-lung ventilation with propofol-remifentanil anesthesia were randomized 1:1 to receive either limb RIPC or conventional lung resection (control). Three cycles of 5-min ischemia/5-min reperfusion induced by a blood pressure cuff served as RIPC stimulus. The primary outcome was Pao(2)/Fio(2). Secondary outcomes included other pulmonary variables, the incidence of in-hospital complications, markers of oxidative stress, and inflammatory response. Results: Limb RIPC significantly increased Pao(2)/Fio(2) compared with control at 30 and 60 min after one-lung ventilation, 30 min after re-expansion, and 6 h after operation (238 +/- 52 vs. 192 +/- 67, P = 0.03; 223 +/- 66 vs. 184 +/- 64, P = 0.01; 385 +/- 61 vs. 320 +/- 79, P = 0.003; 388 +/- 52 vs. 317 +/- 46, P = 0.001, respectively). In comparison with control, it also significantly reduced serum levels of interleukin-6 and tumor necrosis factor-alpha at 6, 12, 24, and 48 h after operation and malondialdehyde levels at 60 min after one-lung ventilation and 30 min after re-expansion (all P < 0.01). The incidence of acute lung injury and the length of postoperative hospital stay were markedly reduced by limb RIPC compared with control (all P < 0.05). Conclusion: Limb RIPC attenuates acute lung injury via improving intraoperative pulmonary oxygenation in patients without severe pulmonary disease after lung resection under propofol-remifentanil anesthesia.