Intrathecal clonidine prolongs labour analgesia but worsens fetal outcome: a pilot study.

Purpose: Intrathecal clonidine prolongs total duration of spinal bupivacaine analgesia. However, there are contradictory reports about its effect on maternal blood pressure and only limited data are available on fetal and neonatal outcome. In this study, we evaluated the efficacy of spinal clonidine combined with ropivacaine and sufentanil and its effects on maternal and fetal outcome.

Methods: Fifty patients requesting combined spinal epidural analgesia for labour pain relief were randomly assigned to receive intrathecal ropivacaine 3 mg, sufentanil 1.5 microg with or without clonidine 30 microg. Onset time and duration of analgesia, visual analogue scores for pain, blood pressure, ephedrine requirements, heart rate, incidence of nausea, pruritus and motor blockade, umbilical artery pH, fetal heart rate abnormalities and Apgar scores were noted and analyzed.

Results: Patients receiving spinal clonidine had significantly longer lasting analgesia compared to patients treated without clonidine (122 +/- 56 min vs 90 +/- 36 min, P < 0.05). Clonidine-treated patients experienced a more pronounced decrease in mean arterial pressure as compared to patients treated without clonidine (25 +/- 10% vs 15 +/- 12%, P < 0.05). The groups also differed in ephedrine requirement (4.91 mg vs 0.75 mg, P < 0.05), number of new onset fetal heart rate abnormalities (28% vs 0%, P < 0.05) and umbilical artery pH (7.219 +/- 0.096 vs 7.289 +/- 0.085, P < 0.05).

Conclusion: Intrathecal clonidine prolongs spinal analgesia with ropivacaine and sufentanil at the expense of maternal hypotension, worse fetal well being and worse neonatal umbilical artery pH. We do not recommend routine administration of spinal clonidine 30 microg to sufentanil and ropivacaine for labour pain relief.