Isobolographic analysis of hypnotic interaction between propofol and ketamine
- VernacularTitle:等辐射分析法研究全麻诱导时异丙酚与氯胺酮的相互作用
- Author:
Hong CHEN
;
Ningling PAN
- Publication Type:Journal Article
- Keywords:
Drug interactions;
Propofol;
Ketamine;
Isobolographic analysis
- From:
Chinese Journal of Anesthesiology
1996;0(07):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To study the hypnotic interaction between propofol and ketamine with isobologram. Methods Seventy-five ASA Ⅰ - Ⅱ patients (35 male, 40 female) aged 20-50 yr, weighing 40-80 kg, undergoing elective upper abdominal surgery were randomly divided into three equal groups of 25 patients : propofol group (P); ketamine group (K) and propofol-ketamine combination group (P/K), Each group was further divided into 5 subgroups. Propofol 0.8, 1.0, 1.25, 1.56 or 1.95 mg ? kg-1 was given in 5 propofol subgroups (P1-5 ) respectively. Ketamine 0.32, 0.40, 0.50, 0.63 or 0.78 mg?kg-1 was given in 5 ketamine subgroups (K1-5 ) respectively. Propofol /ketamine 0.45/0.15, 0.60/0.20, 0.80/0.29, 1.05/0.35 or 1.41/0.47 mg?kg-1 were given in the 5 propofol-ketamine combination subgroups (P/K1-5 ) respectively. Two minutes after drug administration the patients were asked to open their eyes. Failure to open eyes was taken as the start-point of hypnotic effect. If the patient failed to respond to verbal order twice consecutively, the patient was considered to be in the hypnotic state. When the patient in hypnotic state failed to respond to electric stimulation of certain intensity, the patient was considered to be in anesthetic state. ED50s of propofol, ketamine and P/K combination for hypnotic and anesthetic effect were calculated. Isobologram was drawn. ED50 and 95 % confidence limit of ketamine were plotted on the abscissa and of propofol on the ordinate. The ED50 s of the two drugs were connected. If the ED50 of P/K combination was located on the connecting line, the two drugs are additive, on the left side of the connecting line synergistic, on the right side of the connecting line antagonistic. SBP, DBP, HR, SpO2 and BIS were continuously monitored before, during and after drug administration. Results The ED50 s for hypnotic and anesthetic effect were : 1.15 mg? kg-1 and 1.59 mg? kg-1 in group P; 0.40 mg? kg-1 and 0.72 mg? kg-1 in ketamine group; 0.65/0.22 mg?kg-1 and 1.19/0.40 mg?kg-1 in P/K group. The deviation of the location of ED50 of P/K combination from the connecting line was statistically insignificant. There was no significant change in SBP and DBF after administration of drugs in P/K group. Conclusion The hypnotic and anesthetic interaction between propofol and ketamine was additive. In terms of hemodynamic stability, P/K combination was the best among the three groups.
