Effect Of Oxycodone On Loss Of Consciousness And Bispectral Index During Propofol Tci Induction Of Anaesthesia

Objective: We observed the effect of oxycodone on loss of consciousness and bispectral index during propofol taget-controlled infusion induction of anaesthesia.The pharmacodynamic interaction between propofol and oxycodone was preliminarily discussed in order to provide reference basis for safe and rational use of drugs in clinical anesthesia.Methods: Ninety patients undergoing elective general anesthesia,aged 18 to 65 years old,ASA I to II,and body mass index 19 to 24kg/m2,were divided into three groups by random number table method: control group(group C),oxycodone group(group O)and sufentanil group(group S),with 30 patients in each group.The experimental group was given 0.35mg/kg oxycodone or0.5?g/kg sufentanil respectively,and the group C was given the same amount of physiological saline for 1min.Propofol taget-controlled infusion induction was initiated 4min later,and the initial effect-site concentration was set at0.5?g/ml.After effect-site concentration of propofol reached the set value,it continued for 5min,and then increased by 0.5?g/ml until the patient's consciousness disappeared.Then propofol continued to infuse with the effect-site concentration when loss of consciousness.The experimental group received 0.6mg/kg rocuronium for 30 s,and the group C received 0.5?g/kg sufentanil for 1min firstly followed by the same does of rocuronium 2min later,and tracheal intubation was performed after 90 s.The alertness/sedation score(OAA/S)when the effect-site concentration of propofol was reached the set value,the basic bispectral index(BIS)value and BIS value at loss of consciousness and before propofol target-controlled infusion,duration of induction and the the effect-site concentration of propofol at loss of consciousness,and the systolic blood pressure(SBP),diastolic blood pressure(DBP),and heart rate(HR)at each point of time,including pre-administration(baseline),before propofol taget-controlled infusion starts(T1),before intubation(T2),immediately after intubation(T3),1min after intubation(T4),3min after intubation(T5)and 5min after intubation(T6)were recorded.Before leaving the post anaesthesia care unit(PACU)and 24 hours after surgery,the patients were asked whether there was an intraoperative awareness of the intubation process.Results:1.There were no significant differences in age,height,weight,sex and other general data among the three groups(P>0.05).2.Comparison of OAA/S when the effect-site concentration of propofol was reached the set value in three groups(1)Intergroup comparison: There were no significant differences in OAA/S among the three groups when no drugs administrated and the effect-site concentration of propofol was 2.5?g/ml(P>0.05).The OAA/S in experimental group when the effect-site concentration of propofol was 0,0.5,1.0,1.5,2.0?g/ml were significantly lower than that in group C(P<0.05).The OAA/S in group O when the effect-site concentration of propofol was 0.5,1.0?g/ml were significantly higher than that in group S(P<0.05).While there were no significant differences between these two groups when the effect-site concentration of propofol was 0,1.5,2.0?g/ml(P>0.05).(2)Intragroup comparison: The OAA/S in group C when the effect-site concentration of propofol was 1.0,1.5,2.0,2.5?g/ml were lower than the baseline(P<0.05),while there were no significant differences when the effect-site concentration of propofol was 0,0.5ug/ml(P>0.05).The OAA/S in group O when the effect-site concentration of propofol was 0,0.5,1.0,1.5,2.0,2.5?g/ml were lower than the baseline(P<0.05).The OAA/S in group S when the effect-site concentration of propofol was 0,0.5,1.0,1.5?g/ml were lower than the baseline(P<0.05).3.Comparison of BIS value at different time points in three groups There were no significant differences in the basic BIS value among the three groups(P>0.05).The BIS value before propofol target-controlled infusion in experimental group were lower than that in group C,and the BIS value at loss of consciousness in experimental group were higher than that in group C(P<0.05).There was no significant difference in the BIS value before propofol target-controlled infusion and at loss of consciousness between group O and group C(P>0.05).4.Comparison of duration of induction and the effect-site concentration of propofol at loss of consciousness in three groups The duration of induction and effect-site concentration of propofol at loss of consciousness in experimental group were lower than that in group C(P<0.05).There was no significant difference in the duration of induction and effect-site concentration of propofol at loss of consciousness between group O and group C(P>0.05).5.The EC50 and BIS50 and 95% confidence interval of propofol in each group(1)The EC50 and 95% confidence interval of propofol in group C,group O and group S were 1.913(1.906~1.921)?g/ml,1.187(1.163~1.21)?g/ml and1.041(1.02~1.061)?g/ml respectively.The EC50 in experimental group were significantly lower than that in group C.(2)The BIS50 and 95% confidence interval of propofol in group C,group O and group S were 62.41(61.51~63.3),75.39(73.52~77.21)and77.85(76.94~78.77)respectively.The BIS50 in experimental group were significantly higher than that in group C.6.Comparison of hemodynamic parameters at different time points in three groups7.(1)Intergroup comparison: HR at T2,T3,T4,T5 and T6,SBP at T1,T2,T3, T4,T5 and T6,DBP at T3,T4,T5 and T6 in group O were higher than that in group C(P<0.05).HR and SBP at T2,T3,T4,T5 and T6,DBP at T3,T4,T5 and T6 in group S were higher than that in group C(P<0.05).And there were no significant differences at the other time points among the three groups(P>0.05).(2)Intragroup comparison: HR at T2,T5 and T6,SBP and DBP at T2,T3,T4,T5 and T6 in group C were different from the baseline(P<0.05).HR at T3,T4 and T5,SBP at T1,T2,T3 and T6,DBP at T2,T5 and T6 in group O were different from the baseline(P<0.05).HR at T3,T4,T5 and T6,SBP at T2,T3 and T6,DBP at T2 in group S were different from the baseline(P<0.05).And there were no significant differences at the other time points among the three groups(P>0.05).7.All patients had no intraoperative awareness of the intubation process.Conclusions:1.Oxycodone can cause a decrease in OAA/S and BIS values after intravenous injection,with a certain degree of sedative effect.2.Oxycodone can enhance the sedative and hypnotic effects of propofol when combined with propofol target-controlled infusion induction,which believed to be related to the synergistic or additive effect between this two medicine.3.0.35mg/kg oxycodone combined with propofol target-controlled infusion induction can effectively inhibit cardiovascular response induced by endotracheal intubation and maintain hemodynamic stability.