Assessment on the median effective dose of patient-controlled intravenous remifentanil labor analgesia / 中国医师进修杂志

ABSTRACT

Objective To assess the median effective dose (ED50) of patient- controlled intravenous remifentanil labor analgesia. Methods Forty primiparas were selected and randomly divided into 5 groups with 8 cases in each group. Patient-controlled intravenous administration of remifentanil was performed among the 5 groups with differrent doses0.80μg/kg(R1 group), 0.67μg/kg (R2 group), 0.56μg/kg (R3 group), 0.47μg/kg (R4 group), and 0.39μg/kg(R5 group). Probit regression method was adopted to calculate the ED50 and 95% confidence interval of the patient-controlled intravenous remifentanil labor analgesia. The visual analogue scales (VAS) scores following the labor analgesia, pulse oxygen saturation, maternal heart rate, sedation scores and newborn Apgar scores were recorded. Results The ED50 remained at 0.576 μg/kg and the 95% confidence interval was 0.390-0.701μg/kg. The blood pressure and heart rate remained at normal limits, and there were no significant differences among five groups (P>0.05). The newborn 1, 5 min Apgar scores and umbilical arterial pH were no significant differences among five groups (P>0.05). The second stage of labor time, rate of using oxytocin were showed no significant differences among five groups (P>0.05). The VAS scores and sedation scores were no significant differences among five groups (P>0.05). Conclusion The ED50 of patient-controlled intravenous remifentanil labor analgesia is 0.576 μg/kg, and the 95% confidence interval remains at 0.390-0.701μg/kg.