Limb remote ischemic preconditioning on lung protection in patients with thoracoscopic lobectomy: a randomized controlled trial

Abstract

Abstract Background One-lung ventilation (OLV) is often used during lobectomy anesthesia. Inflammation and oxidative stress during OLV can aggravate lung tissue injury, which is an important factor causing postoperative acute lung injury. Studies have confirmed that remote ischemic preconditioning (RIPC) can initiate endogenous protective mechanisms and alleviate injury to target organs. However, whether RIPC has a lung protective effect in patients undergoing lung resection remains unknown. Therefore, this randomized controlled clinical study investigated whether RIPC could reduce OLV-related lung injury, improve intraoperative oxygenation parameters, and induce lung protection in patients with thoracoscopic lobectomy. Methods We adopted a single-center, randomized, single-blind clinical controlled trial method and selected 54 patients who underwent inferior lobectomy with OLV and were randomly divided into a preconditioning group (RIPC group) and a blank control group (NC group). The preconditioning group received lower limb RIPC before OLV, while the blank NC group did not receive RIPC. RIPC was used to perform 5 cycles of 5 min ischemia /5 min reperfusion on the opposite lower limb via a limb ischemia preadaptor. Four time points after anesthesia induction (T0), 30 min after single-lung ventilation (T1), 90 min after single-lung ventilation (T2), and 30 min after double-lung ventilation restoration (T3) were used as the data-recording and blood-collection points. The main outcome measure was the oxygenation index (OI), while the secondary outcome measures included Clara cell secreted protein CC16, inflammatory cytokines (IL-6), serum malondialdehyde (MDA), lung-related variables, and length of hospital stay. Results There was no significant difference in the OI in the RIPC group compared with the NC group at each time point of T0-T3 (P > 0.05), but in general, the OI value of of the RIPC group at the T1-T3 time points showed an increasing trend compared with that of the NC group. There were significant differences in plasma CC16 levels between T1-T3 (P < 0.05), and the plasma CC16 level in the RIPC group was significantly decreased. IL-6 and MDA levels at T1-T3 were lower than those in the NC group (P < 0.05). However, there were no significant differences in blood pH and pulmonary-related variables (respiratory index (RI), alveolar-arterial oxygen partial pressure (A-aDO2), and arterial-alveolar oxygen partial pressure (a/A ratio)) (P > 0.05), and the length of hospital stay was not significantly different (P > 0.05). Conclusions Remote limb ischemic preconditioning can reduce lung injury during lobectomy and can protect lung tissue mainly by reducing the inflammatory and oxidative-stress responses.