A Randomised, Double Blinded Study on Comparison of Intrathecal Morphine and Clonidine as Adjuvant for Post-caesarean Analgesia

Introduction: Caesarean section is a common obstetric operation which requires adequate and safe postoperative analgesia sometimes using morphine or clonidine to provide comfort to the mother and ease in handling the new born. Aim: A randomised double-blinded study was conducted to compare the adjuvant effect of morphine and clonidine when co-administered intrathecally with 0.5% bupivacaine heavy during caesarean section. Materials and Methods: A total 90 parturient were randomly divided into three groups, during March to November 2011, receiving intrathecal 100 mcg morphine, 75 mcg clonidine and 0.5 mL normal saline along with 2.5 mL of bupivacaine respectively. The quality and duration of postoperative analgesia and any side effects were assessed at fixed time interval. APGAR score of foetuses was also done to assess their wellbeing. Statistical analysis was done using Analysis of Variance (for continuous variables like Blood Pressure, heart rate, etc.,) and chi-square test (for discrete variables like VAS score, side effects, etc.,). Results: Postoperative VAS score at different time were much lower in the morphine group as compared to clonidine group (p-value<0.001) at 2,8,24-hour interval postoperative period. The time required for 1st rescue analgesia was longer in morphine (14 +/- 7.33 hours) as compared to clonidine (7 +/- 1.02 hours) (p<0.001). The total dose of rescue analgesic required in 24 hours was less (p<0.001) in morphine (75 +/- 48.25 mg) group. Hypotension bradycardia and sedation (p-value 0.028) were more in clonidine group as compared to morphine group. Conclusion: Low dose morphine is better as an adjuvant than clonidine during spinal anaesthesia for relieving pain following caesarean section.