Efficacy and side effect profile of varying doses of intrathecal fentanyl added to bupivacaine for labor analgesia

• Published in: International journal of obstetric anesthesia Vol. 13; no. 1; pp. 19 - 24
• Main Authors: Wong, C.A, Scavone, B.M, Slavenas, J.P, Vidovich, M.I, Peaceman, A.M, Ganchiff, J.N, Strauss-Hoder, T, McCarthy, R.J
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.01.2004
• Subjects: Adult; Analgesia, Obstetrical; Analgesics, Opioid - administration & dosage; Analgesics, Opioid - adverse effects; Anesthetics, Local; Bupivacaine; Dose-Response Relationship, Drug; Double-Blind Method; Female; Fentanyl - administration & dosage; Fentanyl - adverse effects; Heart Rate, Fetal - drug effects; Humans; Injections, Spinal; Oxytocin - therapeutic use; Pain Measurement; Postoperative Nausea and Vomiting - epidemiology; Pregnancy; Pruritus - epidemiology
• ISSN: 0959-289X; 1532-3374
• DOI: 10.1016/S0959-289X(03)00106-7

The purpose of this randomized, double blinded and controlled study was to determine the optimal dose of intrathecal fentanyl when combined with bupivacaine 2.5 mg for initiation of labor analgesia. Parous parturients with cervical dilation between 3 and 5 cm were randomized to receive intrathecal fentanyl 0 (control), 5, 10, 15, 20 or 25 μg, combined with bupivacaine 2.5 mg, followed by a lidocaine/epinephrine epidural test dose. Visual analog pain scores (VAPS) and the presence of side effects were determined every 15 min until the parturient requested additional analgesia. Fetal heart rate (FHR) tracings were compared between groups. All parturients who received fentanyl ⩾15 μg had VAPS <20 mm and duration of analgesia >15 min, but this was not true for all parturients with fentanyl doses <15 μg. Duration of analgesia was shorter for fentanyl groups 0, 5 and 10 μg, compared to groups 15, 20 and 25 μg, but there was no difference between the 15, 20 and 25 μg groups. There was no difference in the incidence of nausea and vomiting, or in FHR tracing changes. The incidence of pruritus was greater in all fentanyl groups compared to control. These data suggest that, when combined with intrathecal bupivacaine 2.5 mg, fentanyl 15 μg provides satisfactory analgesia to all parturients. Higher fentanyl doses produced no additional benefit in duration or quality of analgesia.