Effect Of Intraoperative Blood Pressure Management On Early Postoperative Acute Kidney Injury In Elderly Patients Undergoing Major Abdominal Surgery

Objective Perioperative acute kidney injury（AKI）refers to a clinical syndrome of kidney injury from one week before operation to 12 days after operation,which includes structural injury and loss of renal function.There are more than 300 million surgical cases in the world every year.Although the medical level is getting higher and higher,the incidence of AKI in hospitalized patients is still as high as 18%.Even minor changes in serum creatinine and/or urine volume show relatively mild damage or renal function damage,which can also predict serious clinical consequences.The incidence of AKI after operation is closely related to intraoperative hypotension.With the increase of age,the total weight of kidney decreased,glomerular sclerosis,renal cortical parenchyma decreased and glomerular basement membrane thickened in elderly patients.These renal changes reduce glomerular filtration rate and increase serum creatinine.Studies have shown that intraoperative Systolic blood pressure（SBP）within the range of 90%～110%of the basic value can reduce postoperative inflammatory reaction and multiple organ dysfunction,and improve the survival rate of patients.The purpose of this study was to observe the effect of maintaining the MAP at 90%～110%of the basic value during operation on AKI in the early postoperative period of elderly patients undergoing major abdominal surgery.Methods 164 patients undergoing major abdominal surgery were randomly divided into two groups:standardized management group（Group S,n=82）,MAP during operation was not lower than 65mm Hg or 80%of the basic level;in the individualized management group（Group I,n=82）,MAP during operation was controlled within 90%～110%of the basic value.MAP were recorded before operation（T₀）,5min after anesthesia（T₁）,at the beginning of surgery（T₂）,30 min（T₃）,60min（T₄）,120min（T₅）,180min（T₆）and at the end of surgery（T₇）.The blood transfusion volume,anesthetic dosage,operation duration,vasoactive drug dosage,infusion volume and urine volume were recorded.Serum creatinine（Scr）,Cystatin c（Cys c）and incidence of AKI after operation were recorded.The number of patients admitted to intensive care unit（ICU）after operation,postoperative hospital stay and 30-day mortality were recorded.Results There was no significant difference in preoperative basic clinical information in the two groups.There was no significant difference in blood transfusion volume,infusion volume,urine volume,anesthetic dosage,and operation time in the two groups.Compared with group S,the amount of norepinephrine and the incidence of bradycardia in group Ⅰ increased significantly（P（27）0.05）.There was no significant difference in the amount of nicardipine,atropine,ephedrine,tachycardia and ventricular premature beats between the two groups.The MAP of two groups was significantly lower than the preoperative basic value.Compared with group S,MAP in group Ⅰ was significantly higher at T1-T7（P（27）0.05）.The concentration of Serum creatinine and Cystatin c in the early postoperative period were significantly lower in group Ⅰ,the incidence of AKI in early postoperative period in group Ⅰ was significantly lower（P（27）0.05）.In group Ⅰ,the ICU admission rate and postoperative hospital stay decreased（P（27）0.05）.There was no difference in mortality between the two groups at 30 days after operation.Conclusion Maintaining 90%～110%of MAP in elderly patients undergoing major abdominal surgery can reduce the incidence of early postoperative acute kidney injury,shorten hospital stay after operation and improve the prognosis of patients.