Effects Of Pre-injection Of Dexmedetomidine On Hemodynamics During Induction Of General Anesthesia With Etomidate Or Propofol

Objective:To observe the effect pre-injection of Dexmedetomidine on hymodynamics during induction of general anesthesia with Etomidate or Propofol.Methods:Eighty patients with ASA I-II scheduled for surgery were randomly assigned to4groups:P (N=20),PD (N=20),E (N=20),ED (N=20). Group PD, ED received Dexmedetomidine1μg/kg intravenous injection and the whole dose was given within10minutes. GroupP, E received equal volume of normal saline as Group PD intravenously without Dex. Anesthesia was induced with Sufentanil0.2μg/kg, Norcuronium O.lmg/kg and Etomidate0.3mg/kg in group E, ED. Anesthesia was induced with propofol2mg/kg in group P, PD, All other induction and maintenance drugs were same for two groups. HR, SBP, DBP, BIS were recorded at the time points of pre-administration of Dexmedetomidine (To,base value),1min after administration(T1),10min after administration(T2), pre-intubation(T3), intubation(T4), 1min after intubation(T5),3min after intubation(T6),5min after intubation(T7). SPO2, Ramesay scale were recorded at the time points of To and T2.Results:Compared with base value, SBP and DBP of group P, PD, E were decreased at T3(P<0.05), There was no obvious change in Group ED(P>0.05), Compared with Group PD, SBP, DBP of Group ED were higher at T3(P<0.05). Compared with Group PD, SBP and NBP of group ED were higher at T4(P<0.05). Compared with Group E, SBP and DBP of group P, PD, E were lower at T5(P<0.05), Compared with To, SBP and DBP of group E were higher at T5(P<0.05). Compared with To, SBP and DBP of group E, ED were similar at T6(P>0.05). Compared with To, SBP and DBP of group P, PD were lower at T6、T7.HR of group PD, ED were lower than group P, E at T2-T6(P<0.05). Compared with To, BIS of group PD and group ED were decreased at T2(P<0.01), BIS of group P, PD, E, ED were similar at T3-T7(P<0.05).Conclusion:Dexmedetomidine can effectively reduce cardiovascular responses to tracheal intubation during induction of general anaesthesia,Dexmedetomidine combined with Etomidate to induction anesthesia is a best method and can remain better instantaneous cardiovascular response to laryngoscope and tracheal intubation than Dexmedetomidine combined Propofol during induction of general anaesthesia.