Median effective effect-site concentration of remifentanil inhibiting responses to laryngeal mask airway insertion when combined with propofol in elderly male patients
10.3760/cma.j.issn.0254-1416.2014.03.015
- VernacularTitle:复合异丙酚时瑞芬太尼抑制老年男性患者喉罩置入反应的半数有效效应室浓度
- Author:
Jian SUN
;
Yuechun LU
;
Guoyi LYU
- Publication Type:Journal Article
- Keywords:
Piperidines;
Propofol;
Aged;
Laryngeal mask;
Dose-response relationship,drugs
- From:
Chinese Journal of Anesthesiology
2014;(3):312-314
- CountryChina
- Language:Chinese
-
Abstract:
Objective To determine the median effective effect-site concentration (EC50 ) of remifentanil inhibiting responses to laryngeal mask airway insertion when combined with propofol in elderly male patients . Methods Thirty ASA physical status Ⅰ or Ⅱ male patients ,aged 65>yr ,with body mass index <30 kg/m2 , scheduled for elective transurethral resection of bladder tumor or prostate under general anesthesia ,were enrolled in this study .Anesthesia was induced with target-controlled infusion of propofol with a target plasma concentration (Cp) of 3 μg/ml .When Observer′s Assessment of Alertness/Sedation (OAA/S ) score ≤1 ,remifentanil target-controlled infusion was started with the initial target Cp set at 4.0 ng/ml . The concentration of propofol was adjusted until BIS value reached 55-65 ,and then the laryngeal mask airway was inserted .Modified Dixon’s up-and-down method was used to determine the Cp of remifentanil . Each time the Cp of remifentanil increased/decreased in the next patient depending on whether or not the response to laryngeal mask airway insertion occurred . The ratio of the two successive Cps was 1.2 .The response to laryngeal mask airway insertion was defined as development of coughing ,laryngospasm and/or body movement during insertion or within 3 min after insertion .The number of patients in whom inhibition of responses to insertion was effective/ineffective was recorded .The EC50 of remifentanil required to inhibit responses to laryngeal mask airway insertion and the 95% confidence interval when combined with propofol were calculated .Results The EC50 (95% confidence interval ) of remifentanil required to inhibit responses to laryngeal mask airway insertion was 1.86 (1.64-2.12) ng/ml when combined with propofol in elderly male patients .Conclusion The EC50 of remifentanil required to inhibit responses to laryngeal mask airway insertion is 1.86 ng/ml when combined with propofol in elderly male patients .
