Clinical Research Of Remote Ischaemic Preconditioning On Myocardial Protection In Hip Arthroplasty

Objective:This study aims to investigate the myocardial protective effect of remote ischaemic preconditioning in hip replacement.Methods:Forty patients with ASA II-III class selection for hip arthroplasty,who were aged 49-88 years old and weighed 33-92kg,including 19 males and 21 females.Preoperative complications included ischemic heart disease in 13 cases and diabetes in 13 cases.Surgical types included total hip replacement in 20 cases and hemihip replacement in 20 cases.The patients were randomly divided into a blank control group(group C)and remote ischemic preconditioning group(RIPC,R group),with 20 cases in each group.Lied on uninjured position,patients were gived epidural anesthesia with 2%lidocaine local anesthesia in the lumbar intervertebral space 2-3 or 3-4.Once confirmed the catheter in the epidural space which not into the blood vessel and subarachnoid space,catheter was placed 4cm toward the head side.With 4ml of 2%lidocaine as the experimental dose,after reconfirming the catheter location,1%lidocaine+0.33%ropivacaine mixture was given,then we complete epidural anesthesia.Testig the block level reached T12,an electric pneumatic tourniquet was tied at the root of the healthy limbs,and the pressure was set at 55kPa.In group R,we start the RIPC with setting the tourniquet on 5min and off 5min,which was repeated for 3 times.While the group C,the tourniquet was applied in without any treatment.30 minutes later,the operation began.Vital signs were recorded every 5 minutes,summary of the operation time and intraoperative input and output volume during postoperative.Myocardial injury markers were examined preoperatively,postoperatively,the first day and the second day after surgery.Electrocardiogram(ECG)was recorded 24 hours two days after operation.The incidence of postoperative pain,intraspinal anesthesia complications,surgical complications and cardiovascular adverse events were followed up within 3 days after operation.Survival and adverse cardiovascular events were followed up 30 days after operation.Results:There was no significant difference in preoperative general information(age,gender,height and weight,etc.)and preoperative assessment(ASA classification,New York Heart Association classification,metabolic activity equivalent,etc.)among the 40 patients,nor was the significant difference in intraoperative vital signs and surgical access between the two groups(P>0.05).There was no statistically significant difference in the preoperative troponin T concentration between the two groups.After surgery,on the first and the second day after surgery,the troponin T concentration was higher than that before surgery,reaching a highest value on the first day after surgery,and then decreased on the second day after surgery.However,there was no significant difference between the two groups(P>0.05).The electrocardiogram of the two groups of patients did not change significantly 2 days after surgery compared with that before surgery(P>0.05).No significant difference in the average hospitalized between the two groups,nor did the hospitalization days after operation(P>0.05).No adverse cardiovascular events occurred in all patients during postoperative follow-up and 30 days after surgery.Conclusion:With limited experimental conditions and sample size,remote ischemic preconditioning,with continuous epidural anesthesia,showed no myocardial protection in patients undergoing continuous epidural hip replacement.