The onset and duration of 0.2% ropivacaine with a varying dose of fentanyl in epidural labor analgesia

ABSTRACT

BACKGROUND: The purpose of this study was to identify the effect of fentanyl dose on the onset and duration of 0.2% ropivacaine. METHODS: Sixty-one nulliparous women with singleton vertex pregnancy who requested epidural labor analgesia were enrolled. Patients were administered randomly 0, 50, 100microgram of fentanyl with 10 ml of 0.2% ropivacaine (Group F0, F50 and F100, respectively). VAS pain scores were recorded 0, 5, 10, 15 min after epidural injection, after which they were recorded every 15 min. The onset and duration of analgesia were measured. Side effects such as, pruritus, motor blockade, and hypotension were recorded.Satisfaction scores, type of delivery, and neonatal outcomes were recorded. RESULTS: The onset of analgesia was at 8.5 +/- 3.4 min in Group F100, compared with 13.7 +/- 7.2 min in Group F0 and 13.6 +/- 5.3 min in Group F50 (P = 0.009). The duration of analgesia was 122.6 +/- 20 min in Group F100, compared with 72.3 +/- 21.2 min in Group F0 and 97.8 +/- 22.4 min in Group F50 (P = 0.000). There were significant differences in VAS pain scores and satisfaction scores among the three groups. There were no differences in the incidences of maternal side effects and operative delivery or neonatal outcomes. CONCLUSION: Fentanyl 100microgram was the most appropriate dose when combined with 0.2% ropivacaine due to the rapid onset and long duration of epidural labor analgesia.