Efficacy of dexmedetomidine mixed with ropivacaine for programmed intermittent epidural bolus technique on labor analgesia and intrapartum maternal hyperthermia
Objective：To evaluate the effects of dexmedetomidine mixed with ropivacaine for programmed intermittent epidural bolus technique on labor analgesia and intrapartum maternal hyperthermia. Methods：A total of 104 singleton full-term parturients，of American Society of Anesthesiologists physical status Ⅰ or Ⅱ，aged 20~35 years，weighing 60~85 kg，scheduled for elective labor analgesia，were divided into 0.1% ropivacaine mixed with 0.5 μg/ml dexmedetomidine(group RD，n=52)and 0.1% ropivacaine mixed with 1 μg/mL fentanyl(group RF，n=52)by a random number table method. Both groups received programmed intermittent epidural bolus technique in labor analgesia. The visual analogue scale(VAS)score and the maternal temperature were measured before anesthesia(T0)，at 30 min(T1)，1 h(T2)，2 h(T3)，4 h(T4)，6 h(T5)post analgesia，10 cm cervical dilatation(T6)and 2 h after delivery (T7). Recording the incidence of breakthrough pain and the adverse effects，the Apgar scores were evaluated at 1 min and 5 min after the delivery. Venous blood samples were collected in non-infusion sides at T0 and T7 to detect the maternal white blood cell count and serum C-reactive protein. Results：Compared with group RF，the onset time of analgesia was significantly shortened，the VAS scores at T2~6 and the incidence of breakthrough pain(4.1% vs. 20.0%)were lower in group RD(P ＜ 0.05). The incidence of intrapartum fever was lower in group RD(8.2% vs. 38.0%)，and also the maternal temperature at T4~7 than those in group RF. Compared with T0，the maternal white blood cell count and C - reactive protein at T7 were significantly higher in both groups（P < 0.01），but there were no significant differences between the two groups at T0 and T（7 P > 0.05）. The incidence of pruritus was lower in the group RD compared to group RF（P < 0.05）. Conclusion：Dexmedetomidine may enhance the efficacy of epidural labor analgesia with ropivacaine and reduce the rate and degree of intrapartum maternal hyperthermia associated with epidural labor analgesia without increasing adverse effects on mother and infant.
