Pain relief after caesarean section: comparison of different techniques of morphine administration

We have studied postoperative pain relief after different techniques of morphine administration given in addition to bupivacaine 15 mg during spinal anaesthesia for caesarean section. In group A, morphine was given both intravenously (10 mg) and orally (30 mg slow release MST) at the end of surgery and continued orally at 8-hourly intervals for 24 h. In group B morphine (80 microg) was given intrathecally only, with the bupivacaine. Both quality of analgesia and duration of action were better in group B, while most side-effects were more frequent in group A where a mild self limiting respiratory depression occurred in 38% of patients. Pruritus was, on the other hand, observed in 48% of patients of group B compared to 7% of the patients of group A. This study suggests that adding 80 microg of morphine to the local anaesthetic used in spinal anaesthesia for caesarean section is a simple procedure that gives excellent results in term of reliability, duration of analgesia and safety.