Neonatal effects of patient-controlled analgesia using fentanyl in labor.

Patient-controlled analgesia (PCA) has been used at our institution for the past 5 years, as an alternative labor analgesic when epidural analgesia is contraindicated. This retrospective study evaluates the effects of maternal PCA fentanyl on infants of greater than 32 weeks gestational age. The neonatal charts (n=32) were reviewed for birth weight, gestational age, 1 min and 5 min Apgar scores, use of naloxone and umbilical venous gases. Infants requiring naloxone were defined as narcotized. Results from narcotized and non-narcotized neonates were compared with the Wilcoxon two-sample test. Fourteen infants had a 1 min Apgar score <or= 6. At 5 min the Apgar scores were all >or= 7, except in the three infants who had received naloxone. Gestational age, birth weight, method of delivery, PCA duration, time from last dose to delivery, total fentanyl used and rate of fentanyl infusion were not predictive of low 1 min Apgar scores. Three infants with a 1 min Apgar of 4 required naloxone. The total fentanyl received by mothers of infants who required naloxone was significantly higher than the group of mothers whose infants did not require naloxone (770 +/- 233 microg vs 298 +/- 287 microg, P = 0.027) Use of PCA fentanyl in this high-risk obstetric population was associated with a 44% incidence of moderately depressed neonates with an Apgar score <or= 6 at 1 min. Prospective controlled trials are needed to determine optimum PCA parameters in labor.