Intrathecal diamorphine compared with morphine for postoperative analgesia after caesarean section under spinal anaesthesia

Abstract

A randomized, double-blind study of 40 women was performed to compare patient controlled anaesthesia (PCA) morphine requirements after spinal anaesthesia for elective Caesarean section. The women received 0.2 mg of either morphine or diamorphine mixed with 0.5% bupivacaine in 8% dextrose. There were no significant differences between the groups in terms of VAS for pain, either while supine or trying to turn over. The median VAS for itching were significantly higher in the morphine group at 3, 4, 6, 8 and 12 h. Similarly, the VAS for drowsiness were significantly higher in the morphine group at 6 and 8 h. Overall there was no difference in the 24-h PCA morphine demands between the two groups (diamorphine patients 5.5 mg, morphine patients 5.0 mg.

A comparison of intrathecal fentanyl and diamorphine as adjuncts in spinal anaesthesia for Caesarean section

“…Patients receiving intrathecal diamorphine receive less supplemental analgesia during surgery [12,20]. Furthermore, Husaini demonstrated a decrease in unwanted side-effects with diamorphine, especially pruritus [8]. These observations formed the basis of our study.…”

“…Fentanyl increases the duration of effective analgesia [5] but this effect is shortlived [15]. Intrathecal morphine as an adjunct to bupivacaine is beneficial for LSCS [8,9], with an optimal dose of 0.1 mg [16][17][18]. Although it does not offer the same benefits during surgery as fentanyl [3], it is better than placebo [19].…”

“…Although ................................................................................................................................................................................................................... diamorphine has a short half-life in the CSF, once it has diffused into neural tissues its active components, 6-acetylmorphine and morphine, are rapidly released by esterases, increasing its duration of action. Recent studies have shown diamorphine to be as effective as morphine for analgesia after surgery [8,9]. The optimum dose of diamorphine is between 0.25 and 0.375 mg, with more side-effects at the higher end of the dose range [20,21].…”

“…Recent studies by Husaini et al [8] and Barkshire et al [9] have shown it to be as effective as morphine for analgesia after surgery, with fewer unwanted side-effects.…”

The National Institute of Clinical Excellence (NICE) guidelines for caesarean sections: implications for the anaesthetist

“…[99][100][101][102][103] Both are effective but diamorphine has fewer and less severe side effects. 100 Both morphine and diamorphine may be given both epidurally and intrathecally, 103 Patient controlled analgesia (PCA) and non-steroidal anti-inflammatory analgesics…”