The effect of intrathecal epinephrine on epidural infused analgesics during labor

Abstract

Background and Objectives: In order to prolong labor analgesia, one may add intrathecal epinephrine to the combination of bupivacaine and fentanyl. In this study, we tested the hypothesis that the addition of intrathecal epinephrine would lessen the requirement for a rescue dose of epidural analgesia during labor. Methods: One hundred-eight parturients randomly received intrathecal bupivacaine 2.5 mg and fentanyl 25 μg, with epinephrine 100 μg (Group BFE) or without (Group BF). Analgesia was assessed by visual analogue pain score (VAPS) 15 and 30 minutes after drug administration. Then, epidural analgesia (0.1% bupivacaine with 0.0002% fentanyl and 1:250,000 epinephrine at 10 mL/h) was initiated. If the patient requested additional analgesia and VAPS was over 30 mm, we added 8 mL epidural bupivacaine 0.125%. The requirement for additional analgesia, the incidence of motor block assessed by a modified Bromage score, hypotension, nausea, and pruritus was noted. Results: Except for 3 parturients in Group BF, satisfactory analgesia was achieved in all parturients 30 minutes after intrathecal drug administration. Following 30 minutes of intrathecal drug administration, VAPSs (mean ± SD) were 0 ± 4 mm in Group BFE and 4 ± 11 mm in Group BF. The number of patients who required additional labor analgesia in Group BFE (11 patients, 20%) was significantly less than in Group BF (26 patients, 48%) (P = .003). The incidence of motor block 30 minutes after spinal analgesia in Group BFE (12 patients, 22%) was significantly higher than in Group BF (3 patients, 6%) (P = .024). Nausea and pruritus were similar in both groups. Conclusion: The addition of epinephrine to intrathecal bupivacaine-fentanyl lessened the requirement for additional epidural analgesia without increasing hypotension, nausea, or pruritus. However, the incidence of motor block may be increased without labor prolongation. Reg Anesth Pain Med 2003; 28:108-112.