Application Of Dexmedetomidine-assisted Controlled Hypotension In Hepatectomy Surgery

Objective: To observe the safety and effectiveness of dexmedetomidine-assisted Controlled Hypotension during hepatectomy Surgery.Methods: A total of 20 patients undergoing selective hepatectomy surgery were randomly divided into dexmedetomidine group(group D)and Saline group(group S)as a control,with 10 cases in each group.Nitroglycerin was pumped at the beginning of the operation,dexmedetomidine was simultaneously pumped in group D,and saline was pumped at the same dose in group S.Adjust the pumping speed according to the MAP,so that the MAP decreased and maintained at 60-70 mmHg and the SBP was more than 80 mmHg.The blood pressure reduction operation was stopped when the main operation steps were completed.The MAP and HR of patients at different time points were observed and recorded.The average dosage of sufentanil,remifentanil and nitroglycerin and Riker's sedation and agitation score before extubation were recorded.The liver function indexes(ALT and AST)were recorded before and 24 hours after surgery.Results: There was no significant difference in MAP at T1 and T2 between the two groups(P > 0.05).Compared with group S at T3,group D was significantly lower(P < 0.05),indicating that the controlled hypotension in group D was more effective;the trend of MAP decline in group D was more gentle than that in group S,indicating that dexmedetomidine assisted controlled hypotension was more stable.There was no significant difference in HR between the two groups at each time point(P > 0.05).The indexes of liver function after operation in both groups were significantly higher than those before operation,and the difference was statistically significant(P < 0.05).There was no significant difference in hepatic function before and after operation between the two groups(P > 0.05),which may be related to the length of hepatic hilum occlusion and the size of the liver tissue removed.There was a linear regression relationship between the time of hepatic hilar occlusion and the increase of ALT and AST in both groups,and the regression coefficient in group S was higher than that in group D.It indicated that intraoperative dexmedetomidine could weaken the correlation between hepatic function injury and the time of hepatic hilar occlusion.The average dosage of sufentanil,remifentanil and nitroglycerin in group D was significantly lower than that in group S(P < 0.05).Compared with Riker sedation and restlessness score before tracheal extubation,there was significant difference between group D(3.36+0.67)and group S(4.22+0.67)(P < 0.05),indicating that intraoperative dexmedetomidine assisted with controlled hypotension could make patients recover more comfortably.Conclusions: Controlled hypotension assisted by dexmedetomidine in partial hepatectomy can make the hypotension more stable and efficient,educe the average dosage of fentanyl and nitroglycerin,make the recovery more comfortable and stable,and may reduce the liver ischemia-reperfusion injury.