BACKGROUND Intrathecal sufentanil has been found to provide profound analgesia during labor. Epinephrine, when added to various local anesthetic agents or opioids, may modify the analgesic profile and incidence of side effects. The authors sought to determine the effect of adding 0.2 mg epinephrine to 10 micrograms sufentanil when administered for analgesia during labor. METHODS Forty women during active labor received 10 micrograms intrathecal sufentanil either with (n = 20) or without (n = 20) 0.2 mg epinephrine in a randomized, blinded fashion. A combined spinal-epidural technique was used in which a 25-G Whitacre spinal needle was passed through a standard 17-G epidural needle. After injection of the study drug, an epidural catheter was passed, but no local anesthetics were given. Analgesia was quantitated using visual analog scores, as well as time elapsed until first request for additional analgesia via the epidural catheter (0.25% bupivacaine). The incidence and severity of pruritus, nausea, and somnolence were assessed. RESULTS The duration (median, range) of analgesia was 90 (40-310) min in the plain sufentanil group (SUF) and 90 (45-230) min in the sufentanil-epinephrine (SUF-EPI) group (P = NS). The onset of analgesia was rapid (within 5 min) in both groups and visual analog scores did not differ at any observation point between groups. The incidence of pruritus was 80% (16/20) in the SUF group, and 45% (9/20) in the SUF-EPI group (P = 0.05). Four patients in the SUF group rated the pruritus as severe versus none in the SUF-EPI groups (P = 0.05). Seven patients (35%) in the SUF-EPI group experienced nausea, versus none in the SUF group (P = 0.004). No patient developed hypotension, motor blockade, fetal heart rate abnormalities, excessive sedation, or postdural puncture headache. CONCLUSIONS Intrathecal sufentanil 10 micrograms, both with and without epinephrine, provided rapid-onset, albeit short-duration, analgesia during labor. Epinephrine did not prolong the duration of intrathecal sufentanil analgesia. The addition of epinephrine increased the incidence of nausea and decreased the incidence and severity of pruritus.