Background: To compare the analgesic efficacy of epidural infusions of levobupivacaine, bupivacaine and ropivacaine in labor.
Methods: 102 nulliparous parturients in early labor were enrolled in this randomized, double-blind clinical trial. They were randomly assigned to receive one of three continuous epidural infusion regimens: levobupivacaine 0.125%, bupivacaine 0.125% or ropivacaine 0.2%, all with fentanyl 1 microg/mL at 8 mL/h. Supplementary analgesia was provided with an 8-mL epidural bolus of the study solution if visual analogue scale (VAS) score for pain was 40 (0-100 mm). Pain and motor and sensory block were measured at 0, 15 and 30 min, 1, 2, 3 and 4h and full cervical dilatation.
Results: Analgesia was satisfactory in all three groups, with VAS score <40 mm at all measurements. VAS scores were greater in those receiving levobupivacaine (P<0.005). Motor block was greater with bupivacaine than levobupivacaine (P<0.01). There were no differences in motor block between levobupivacaine and ropivacaine. There were no other differences between groups.
Conclusion: All three regimens were effective during first stage of labor although pain scores were higher in those receiving levobupivacaine. Motor block was greater with bupivacaine than with levobupivacaine.