Transcutaneous Electrical Acupoint Stimulation Attenuates Lung Injury Caused by Tourniquet-induced Limb Ischemia/reperfusion During Lower Extremity Surgery: A Randomized Controlled Trial

Abstract

Background: Tourniquet-induced extremity ischemia-reperfusion injury is one of the major complications in patients with lower extremity surgery, while lung is the most vulnerable organ to insult subsequent to ischemia-reperfusion. Current scientific research data has shown that electric stimulation at special acupoints could suppress inflammasome activation and subsequently exert protective effects in the lungs. Thus, the effect of transcutaneous electrical acupuncture point stimulation (TEAS) on lung injury induced by limb ischemia/reperfusion remains to be elucidated. Methods: One hundred individuals scheduled for unilateral lower extremity surgery were randomly divided into 2 groups (n=50 each): transcutaneous electrical acupoint stimulation group (group T) and control group (group C). Patients in group T were given TEAS at FeiShu (BL13, bilateral) acupoints and ZuSanLi (ST36, non-surgical side) acupoint, while patients in group C received sham stimulation (no current) at the same acupoints for the same time as the TEAS group. Arterial blood samples were collected to assess blood gas analysis and other indicators. Results: The TEAS group showed significant improvements in blood gas analysis. Compared with group C, PaO2 and oxygenation index (OI) in group T were significantly increased at T4(4h after removing the tourniquet), while A-aDO2 and respiratory index (RI) were decreased at T4. There was an increase in the HO-1 levels in group T at T3(2h after removing the tourniquet) and T4 compared with group C. Compared with group T, SOD levels were significantly lower at T4 in group C. At T4, the levels of ICAM-1, IL-6 and IL8 were significantly lower in group T when compared to group C. At T3 and T4, IL-10 levels were higher when compared to group C, while TNF-a levels were significantly lower.Conclusions: Transcutaneous electrical acupoint stimulation attenuates lung injury following tourniquet-induced extremity ischemia-reperfusion in patients, and HO-1 is endowed of potential mechanism of cytoprotective effects against tourniquet-induced lung injury. Trial registration: Chinese Clinical Trial Registry, ChiCTR-IOR-16008264. Registered 11 April 2016, http://www.chictr.org.cn/ ChiCTR-IOR-16008264