Mechanism of Cardiac and Cerebral Function Injury Caused by Intraoperative Limb Ischemia-reperfusion

As a simple auxiliary tool for lower extremity orthopedic surgery, tourniquet can effectively reduce intraoperative bleeding and ensure the clarity of the operative field, effectively shorten the operation time and improve the operation efficiency. The extensive use of tourniquets in lower extremity surgery will not only cause local paralysis, pain and other complications, but also bring about postoperative complications such as large drainage volume and deep vein thrombosis. Recent studies have found that tourniquet induced ischemia-reperfusion injury not only affects the local tissue structure and function of skeletal muscle, but also causes reperfusion injury in distant organs (such as heart, lung and brain). Therefore, improving tourniquet ischemia-reperfusion injury after knee replacement is of great significance to improve the quality of life of patients during the perioperative period. Therefore, the aim of this study was to investigate the effects of dexmedetomidine and tourniquet pretreatment on myocardial injury and brain injury caused by lower extremity ischemia-reperfusion.

Inclusion Criteria:Patients undergoing TKA under general anesthesiaVoluntarily sign the informed consentASA Grade I to IIIBMI 18-28 kg/m2Exclusion Criteria:Congenital heart disease or history of cardiac surgery, heart conduction disease, frequent ventricular/atrial premature beats, atrial fibrillation and other serious arrhythmiasSevere liver disease and kidney diseaseTemporary and permanent pacemaker implantationPatients with serious central nervous system diseases or serious mental disordersRecent history of sedation, antidepressant or opioid useBody mass index >35kg/m2Participants in other clinical trials within 1 month prior to study enrollment.