A comparison of epidural diamorphine with intramuscular papaveretum following caesarean section

Following caesarean section carried out under epidural blockade using local anaesthetic only, 40 consenting women were randomly allocated to receive either epidural diamorphine 2.5-5 mg in 10 ml physiological saline and intramuscular saline or epidural saline and intramuscular papaveretum 10-20 mg, dosage depending on weight, when the pain returned. When analgesia was next requested the alternative treatment was given. A visual analogue pain score was recorded before and 15, 30, 60, 120, 180 and 240 min after the first treatment. Respirations were counted and symptoms noted. On the following day the mother was asked whether she preferred the first or the second treatment. Both treatments produced a reduction in pain score but analgesia was significantly better with epidural diamorphine and the duration of action (8.5 +/- 5.2 h) was significantly longer than that following intramuscular papaveretum (4.1 +/- 2.3 h, P < 0.01). Two mothers who received epidural diamorphine initially required no further analgesia. No difference in respiratory rate was noted but side-effects were more frequent with epidural diamorphine. Despite this more women preferred this treatment. Because of enhanced mobility provided by good analgesia epidural diamorphine is worth offering to women following caesarean section.