Effects of target-controlled infusion of dexmedetomidine on the median effective concentration of effect-site of propofol at loss of consciousness
- VernacularTitle:靶控输注右美托咪定对丙泊酚致意识消失效应室半数有效浓度的影响
- Author:
Zhaoxin ZHENG
;
Bo XU
;
Xing'an ZHANG
;
Weifeng TU
- Keywords:
Dexmedetomidine;
Propofol;
Loss of consciousness;
Target-controlled infusion;
Median effective concentration of effect-site
- From:
The Journal of Clinical Anesthesiology
2017;33(2):125-128
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effects of target-controlled infusion (TCI)of dexme-detomidine on the median effective concentration of effect-site (Ce50 )of propofol at loss of conscious-ness (LOC)in patients.Methods Sixty-four patients,28 males and 36 females,aged 20-60 years, ASA physical status Ⅰ or Ⅱ,scheduled for elective surgery,were randomly allocated to receive dexmedetomidine of 0 ng/ml (group P),dexmedetomidine of 0.4 ng/ml (group D1),dexmedetomi-dine of 0.6 ng/ml (group D2)and dexmedetomidine of 0.8 ng/ml (group D3)for 1 5 min before TCI of propofol,n =1 6 in each group.The propofol infusion was started to provide an effect-site concen-tration of 1.0 μg/ml,and increased by 0.2 μg/ml when propofol effect-site concentration and target concentration were equilibrium until LOC.Results The Ce50 (95%CI )at loss of consciousness in groups P,D1,D2 and D3 were 2.30 (2.24-2.36)μg/ml,1.92 (1.87-1.96 )μg/ml,1.60 (1.55-1.65)μg/ml and 1.41 (1.35-1.45 )μg/ml,respectively.There was a negative correlation between the effect-site concentration of propofol-induced LOC and target concentration of dexmedetomidine (r=-0.84,P <0.01).Compared with groups P,D1 and D2,the incidence of bradycardia was higher in group D3 (P <0.05).Conclusion The Ce50 of propofol-induced LOC gradually decreases with in-creasing target concentration of dexmedetomidine.Combining propofol with dexmedetomidine of 0.4 or 0.6 ng/ml that can reduce the Ce50 of propofol-induced LOC,which is suitable for induction of an-esthesia with a lower incidence of bradycardia.
