Effects Of General Anesthesia With Dexmedetomidine On Hemodynamics In Patients Undergoing Gastrointestinal Surgery

Objective:To observe the effects of dexmedetomidine on hemodynamics and postoperative recovery in patients undergoing gastrointestinal surgery.Methods:120ASA physical status I or II patients were randomly assigned into2groups:control group(group A) and dexmedetomidine group(group B).60cases in each group.in group A,midazolam0.05mg/kg was given before anesthesia induction,then propofol was continuously given at4-8mg/kg/h till the end of surgery.In group B,dexmedetomidine was given with1μg/kg within15min before the induction of anesthesia,then was continuously given at0.6-1.0μg/kg/h till the end of surgery.While In two groups, anesthesia was induced with sulfentanyl、etomidate、 vecuronium and dexamethasone.Both of patients were inhaled sevoflurane (VOL%:1-3%) till15minutes before the end of surgery.Endotracheal tube was removed after the operation, then patients were left to observe30minutes.Hemodynamic changes were recorded at following time points:after entering operating room(D1),5minutes after given dexmedetomidine (or intravenous injection midazolam)D2,15min after given dexmedetomidine (D3),at the moment of intubation(D4),1、2、5、10min after intubation (D5-D8); at the beginning of operation(P1),entering the abdominal cavity(P2),gastrointestinal exploration(P3), gastrointestinal resection(P4),gastrointestinal anastomosis(P5),at the end of operation(P6); before extubation(T1),at the time of extubation(T2)and1、3、5、10minutes(T3-T6) after extubation.Ramsay sedation score and RICHMOND agitation-sedation scale score were recorded at following time points:10、15、30min (L1-L3) after extubation.The respiratory recovery time,emergence time and extubation time were observed.Result:1、The induction period:compared with D1in group B, MAP、HR at D3decreased significantly (P＜0.05); compared with group A,SBP、DBP、MAP、HR at D4-D7of group B decreased significantly (P＜0.05).2、Operation process:compared with P1in group A,SBP、DBP、MAP、HR at P2-P4significantly increased(P <0.05);compared with group A,DBP、SBP、MAP、HR at P2-P5of group B significantly increased(P<0.05).3、The extubation period:compared with T1in group A,MAP、HR at T2-T5each time was significantly increased(P<0.05),and was significantly higher than the same time in group B(P<0.05);there was no significant difference in SpO2between two groups.4、Recovery period:there was no significant difference in the time to respiratory recovery,emergence and extubation in all groups.5、Sedation scores:compared with group B,the Ramsay sedation score and Rass score in patients of group A at L1、L2decreased significantly(P<0.05).Conclusion:Dexmedetomidine was given with1μg/kg within15min before the induction of anesthesia,then was continuously given at0.6-1.0ug/kg/h during gastrointestinal surgery can effectively maintain hemodynamic stability,perfectly inhibit stess reaction,provide perfect sedation and palinesthesia.