Pharmacodynamic interaction of esketamine and propofol in hysteroscopic surgery
Objective To analyze the pharmacodynamic interaction of esketamine and propofol in hysteroscopic surgery by response surface method.Methods Forty-five patients underwent elective hystero-scopic surgery,aged 18.5-64.0 years,BMI 18.5-28.0 kg/m2,ASA physical status Ⅰ or Ⅱ.Compound propofol target control infusion of esketamine(0,0.1,0.2,0.3,0.4,0.5,0.6,0.7,and 0.8 μg/ml)with different plasma drug concentrations were selected to keep the plasma drug concentration of esketamine unchanged,and the plasma drug concentration of propofol was increased step by step.To evaluate body re-sponse caused by dilation of the cervix.A response surface model was used to analyze the pharmacodynamic interaction of esketamine and propofol.Results The three-dimensional response surface of esketamine(0.0-0.8 μg/ml)and propofol(1.0-7.0 μg/ml)showed that the two have an additive effect in sedation and inhibition of body activity reaction caused by dilated cervix.The median effective concentration(EC50)of esketamine was 0.61 μg/ml(95%CI 0.41-0.81 μg/ml),and the EC50 of propofol was 4.69 μg/ml(95%CI 3.17-6.21 μg/ml)when inhibits the body activity reaction caused by dilated cervix.Conclusion Response surface method can qualitatively and quantitatively analyze the pharmacodynamic interaction of es-ketamine and propofol.Esketamine and propofol have additive effects in inhibiting the body activity reaction caused by dilated cervix.