Decreased postpartum use of oral pain medication after a single dose of epidural morphine.

Abstract

Pain after vaginal delivery may result from episiotomy, perineal laceration, or uterine involution. Many women have indwelling epidural catheters in place at delivery. We hypothesized that a small dose of epidural morphine would be an effective strategy for postpartum analgesia. Eighty-one healthy parturients receiving epidural analgesia for labor were enrolled. Patients were randomized in double-blind fashion to 1 of 3 groups: all groups received a 4-mL volume of epidural solution consisting of saline (group 1, control), 1 mg (group 2), or 2 mg morphine (group 3) after vaginal delivery. During the first 24 hours postpartum, patients were evaluated for the amount of oral pain medication requested; visual analog scale scores for pain at rest and with movement; satisfaction with postpartum pain treatment; and opioid side effects including nausea, pruritus, urinary retention, and respiratory depression. Patients who received 2 mg of epidural morphine used an average of 0.7 (0-1, interquartile range) opioid-containing pain pills (acetaminophen with codeine or oxycodone) compared with 1.2 (0-2) in the 1-mg group and 1.9 (0-3) in the control group ( P = .07). There was a statistically significant difference in oral drug usage between those who received epidural morphine and those who did not ( P < .03). There were no differences in side effects except that at 12 hours postpartum there was an increase in Foley catheterization in the 1-mg morphine group ( P = .007). These results suggest that epidural morphine decreases the need for oral pain medication in the first 24 hours postpartum. No significant dose-dependent side effects were found.