Median effective target plasma concentration of remifentanil inhibiting responses to skull-pin placement when combined with propofol in female patients undergoing neurosurgery
10.3760/cma.j.issn.0254-1416.2017.02.018
- VernacularTitle:复合异丙酚时瑞芬太尼抑制神经外科女性患者安置头架反应的半数有效血浆靶浓度
- Author:
Chengwei YANG
;
Danjun LU
;
Fang KANG
;
Xiang HUANG
;
Juan LI
- Keywords:
Piperidines;
Propofol;
Female;
skull-pin;
Dose-response relationship,drug;
Drug delivery systems
- From:
Chinese Journal of Anesthesiology
2017;37(2):196-198
- CountryChina
- Language:Chinese
-
Abstract:
Objective To determine the median effective target plasma concentration (EC50) of remifentanil inhibiting responses to skull-pin placement when combined with propofol in the female patients undergoing neurosurgery.Methods Sixteen female patients,aged 20-60 yr,with body mass index of 18-30 kg/m2,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,scheduled for elective neurosurgery under general anesthesia,were enrolled in this study.Anesthesia was induced with propofol and remifentanil given by target-controlled infusion and iv rocuronium 0.6 mg/kg.The target plasma concentration (Cp) of remifentanil and propofol was set at 5 ng/ml and 3 μg/ml,respectively.At 3 min after tracheal intubation,the target Cp of remifentanil was adjusted and set at 5 ng/ml in the first patient.The skull-pin was placed after the target effect-site and plasma concentrations were balanced.The Cp increased/decreased by 20% each time in the next patient depending on whether or not the response to skull-pin placement was positive.The ratio between the two successive concentrations was 1.2.The response to skull-pin placement was defined as positive when heart rate and/or mean arterial pressure increased by 20% of the baseline value within 1 min after placement.The EC50 and 95% confidence interval of remifentanil required to inhibit responses to skull-pin placement were calculated when combined with propofol.Results The EC50 (95% confidence interval) of remifentanil required to inhibit responses to skull-pin placement was 3.74 (3.43-4.09) ng/ml when combined with propofol.Conclusion When combined with propofol,the EC50 of remifentanil inhibiting responses to skull-pin placement is 3.74 ng/ml in the female patients undergoing neurosurgery.