Effects of a continuous low-dose clonidine epidural regimen on pain, satisfaction and adverse events during labour: a randomized, double-blind, placebo-controlled trial.

BACKGROUND AND OBJECTIVE: Epidural clonidine has been proposed as an adjunct for anaesthetic mixtures during labour. Administered as a bolus, clonidine may have side effects such as sedation and hypotension; its continuous infusion could be attractive in this respect. We, therefore, conducted a randomized, double-blind trial using patient-controlled epidural analgesia with a background infusion using a low dose of clonidine during labour. METHODS: A total of 128 healthy parturients in active labour received a patient-controlled epidural analgesia solution of 0.0625% levobupivacaine and sufentanil 0.25 microg ml(-1) with or without clonidine 2 microg ml(-1). Ninety-five parturients were analysed. The pain score over time was evaluated as well as drug volume utilization; supplementation bolus and side effects were recorded. The primary endpoint was maternal satisfaction [ClinicalTrials.gov Identifier (NCT00437996)]. RESULTS: Three patients in the control group failed to achieve satisfactory epidural analgesia owing to a technical issue. Although the primary endpoint was not statistically significant, analgesia was more pronounced and obtained earlier in the clonidine group. The area under the curve for the visual analogue pain score was significantly lower in the clonidine group. In this group, hourly doses of levobupivacaine and sufentanil were reduced (13.9 +/- 4.3 vs. 16.3 ml +/- 4.0; P = 0.005) as well as rescue supplementation and pruritus incidence (18 vs. 46%; P = 0.004). Maternal blood pressure was significantly lower, over time, in the clonidine group but remained within the normal range. Sedation was similar in both groups (4.3 vs. 2.0%; not significant). CONCLUSION: The addition of clonidine to epidural levobupivacaine and sufentanil for patient-controlled epidural analgesia in labour improved analgesia, reduced the supplementation rate and reduced pruritus without improvement in maternal satisfaction. Blood pressure was significantly lower in the clonidine group over time but without clinical consequence.