[Peridural analgesia in labor. Comparison between bupivacaine and 2-chloroprocaine].

The purpose of this study was the comparison of the effects on the labor and neonates of epidural analgesia conducted either with bupivacaine or 2-chloroprocaine. Hundred and three parturients were included in the study. They were randomly divided in two groups. Sixty-three patients received bupivacaine in 0.25% solution and 40 received 2-chloroprocaine in 2% solution. Epinephrine was not added to local anesthetics. The first dose was 25 mg of bupivacaine (10 ml) or 200 mg of 2-chloroprocaine (10 ml). Reinjections occurred every 30 min for 2-chloroprocaine (80 mg) and every hour for bupivacaine (10 mg). The time of onset of cutaneous analgesia was similar in both bupivacaine (12.5 +/- 4.7 min) and 2-chloroprocaine (13.8 +/- 5.1 min) patients. The incidence of incomplete or insufficient analgesia was significantly higher with 2-chloroprocaine. The number of parturients who required forceps for conclusion of childbirth was not statistically different with bupivacaine (n = 25, 40%) or 2-chloroprocaine (n = 11, 28%) (CHI2 = 1.5971, p = 0.2063). The second stage of labour was significantly longer in parturients who required forceps extraction in both groups. These patients also received significantly more local anesthetics. All newborns had an Apgar score performed before the third minute following birth. All observed Apgar scores except one of bupivacaine group were over eight. Umbilical cord blood was drawn for pH determination. Cord blood pH was slightly but significantly lower in bupivacaine (7.314 +/- 0.106) than in 2-chloroprocaine (7.345 +/- 0.06) patients (t = 1.6968, p = 0.046). Newborns extracted with forceps after maternal bupivacaine epidural analgesia had a significantly lower umbilical blood pH (7.278 +/- 0.117) than newborns who did not required forceps in the bupivacaine group (7.337 +/- 0.093) (t = 2.1986, p = 0.0159).(ABSTRACT TRUNCATED AT 250 WORDS)