A comparative study of neuraxial block for post-cesarean analgesia and side effects: Intrathecal vs epidural morphine

Background: Neuraxial morphine can provide an effective post-cesarean analgesia with minimal systemic effects on the parturients. Our study aimed to compare two different neuraxial blocks-intrathecal and epidural injections in Cesarean section for post-operative analgesia and side effects. Methods: This prospective observational study included 108 ASA I or II patients who underwent elective Cesarean section with central neuraxial block. The parturients either received intrathecal morphine (ITM) of 0.1 mg or epidural morphine (EDM) of 3mg via combined spinal/ epidural block. An additional oral diclofenac sodium and paracetamol were also given as part of multimodal post-operative analgesia. The pain scores were assessed by using the 0-10 Verbal Numerical Rating Scale (VNRS), with rescue medication given to those with scores>4. Side effects were also recorded and treated accordingly. Results: Both ITM and EDM groups showed equally good post-operative analgesic results with the highest median VNRS of only 1. There were no other additional rescue analgesics required. However, side effects were significantly higher in the ITM group as compared to the EDM group in terms pruritus (76.9% vs. 40.0%, p <0.001), nausea (35.9% vs. 10.0%, p=0.008) and vomiting (29.5% vs. 6.7%, p=0.012). None of the patients developed respiratory depression. Conclusion: While both intrathecal and epidural morphine were equally effective as postcesarean analgesia, epidural morphine was deemed to be more superior because of its lower incidence of side effects.