PCEA compared to continuous epidural infusion in an ultra-low-dose regimen for labor pain relief: a randomized study

Background: Patient-controlled epidural analgesia, PCEA, has been introduced in obstetric analgesia during the past decade. Many studies have shown that the consumption of analgesic is reduced when the parturient requests her own doses. This study investigates whether this is also true when using an ultra-low-dose regimen. Methods: Eighty parturients were prospectively randomized to have either continuous epidural infusion (CEI) with ropivacaine 1 mg ml(-1) and sufentanil 0.5 mug ml(-1), 6 ml h(-1), or patient-controlled epidural analgesia ( PCEA) with 4 ml demand doses with 20 min' lockout. The epidural start dose was the same for the two groups, 8 ml of the study solution. Rescue bolus doses were given when needed and the continuous infusion could be increased, which gave the two groups the same maximum possible dose. The consumption of local ropivacaine in combination with sufentanil during labor was registered. Hourly assessments made throughout labor included pain intensity documented with visual analog score, VAS, the patient's opinion on epidural efficacy, motor block, pruritus and need for nitrous oxide. Results: The PCEA group consumed 33% less of the study solution than the CEI group. Mean total consumption was 35 ml (SD 18.0) and 52 ml (SD 19.6), respectively. Mean hourly consumption was 5.2 ml h(-1) (SD 2.54) in the PCEA group and 6.9 ml h(-1) (SD 1.31) in the CEI group. There were no significant differences between the two groups in pain relief, epidural efficacy, side-effects or obstetric outcome. Conclusion: PCEA reduces doses compared to continuous infusion even when ultra-low-dose local anesthetic with opioid is used. The PCEA technique provides individual titration of doses to an acceptable degree of pain relief.