Intrathecal meperidine for labor analgesia: preliminary communication

The authors administered intrathecal meperidine 10 mg to 10 healthy laboring women to determine its analgesic quality, onset, duration, and side-effect profile. When patients requested pain relief, we injected 10 mg preservative-free meperidine in 1 ml normal saline through a 32 gauge spinal catheter. We administered a second dose of meperidine 10 mg if analgesia was inadequate at 10 min. Additional doses of intrathecal meperidine or bupivacaine were administered on request. All patients received local anesthetic intrathecally or by infiltration for delivery. Eight patients were pain-free following meperidine 10 mg, the other 2 patients were comfortable after the second 10 mg meperidine dose. Three patients did not request further labor analgesics and delivered 58, 66 and 244 min following their initial injection of intrathecal meperidine. The mean duration of analgesia in the other 7 patients was 136 +/- 58 (mean +/-SD) min. Six of the 10 women in the study delivered vaginally; 3 spontaneously and 3 with vacuum or forceps assistance. Four patients delivered by cesarean section for failure to progress. Side-effects (which were easily treated) consisted of: pruritus (n = 1), vomiting (n = 2), hypotension (n = 2) and changes in fetal heart rate pattern (n = 5). All infants were vigorous and had good Apgar scores at birth. In conclusion, intrathecal meperidine is a promising labor analgesic, but the effect of meperidine on maternal blood pressure, fetal heart rate pattern, and the progress of labor need to be determined.