Comparison between continuous subarachnoid block with ropivacaine or sufentanil either alone or in combination for labor analgesia

Abstract

Objective To compare the continuous subarachnoid block with ropivacaine or sufentanil either alone or in combination for labor analgesia. Methods Ninety nulliparous parturients who required labor analgesia voluntarily, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, aged 23-35 yr, with a body height of 155-170 cm, were included in this study.When regular uterine contraction appeared, labor analgesia was performed in the first stage of labor.The parturients were divided into 3 groups(n=30 each)using a random number table: ropivacaine group(group R), sufentanil group(group S), and combination of ropivacaine and sufentanil group(group RS). The spinal catheter was placed at L3, 4 interspace.In group R, ropivacaine was given as an initial bolus of(0.6 mg/ml)5 ml followed by an infusion of 0.2 mg/ml after the analgesia pump was connected.In group S, sufentanil was given as an initial bolus of(1.6 μg/ml)5 ml followed by an infusion of 0.2 μg/ml after the analgesia pump was connected.In group RS, the mixture of ropivacaine 0.3 mg/ml plus sufentanil 0.8 μg/ml was given as an initial bolus of 5 ml, followed by an infusion of the mixture of ropivacaine 0.1 mg/ml plus sufentanil 0.1 μg/ml after the analgesia pump was connected.The analgesia pump was programmed to deliver a 5 ml bolus dose with a 15 min lockout interval, background infusion at a rate of 5 ml/h, and the total volume of 100 ml in the three groups.The analgesia pump was connected at 30 min after the initial bolus was given, and the infusion was stopped at 2 h after delivery in the three groups.Visual analog scale(VAS)scores were maintained ≤3.VAS scores were recorded before analgesia and at 5, 10 and 30 min after the initial bolus was given.The interval and duration of uterine contraction were recorded before analgesia, in 0-30 min, 30-60 min and 90-120 min of analgesia periods, and in the second stage of labor.The development of nausea and vomiting, pruritus, lateral episiotomy, assisted vaginal delivery, cesarean section, and post-dural puncture headache and requirement for oxytocin were recorded.Apgar scores at 1, 5 and 10 min after birth were recorded. Results The Apgar score of the newborn was more than or equal to 7 at 1, 5 and 10 min after birth in the three groups.Compared with the value before analgesia, the interval of uterine contraction was significantly prolonged, and the duration of uterine contraction was significantly shortened in the 0-30 min of analgesia period in group R(P 0.05). Compared with group R, the VAS scores were significantly increased at 5 and 10 min after the initial bolus was given, the interval of uterine contraction was significantly shortened, and the duration of uterine contraction was significantly prolonged in S and RS groups, and the incidence of pruritus was significantly decreased in group S(P 0.05). Conclusion Continuous subarachnoid block with combination of ropivacaine and sufentanil provides better efficacy for labor analgesia than either alone. Key words: Amides; Sufentanil; Anesthesia, spinal; Analgesia, obstetrical