The effects of intrathecal diamorphine on gastric emptying after elective Caesarean section

This study investigated whether intrathecal diamorphine affects gastric emptying following elective Caesarean section. Forty women were randomly allocated to receive either diamorphine 300 microg or 0.9% saline as part of a standard spinal anaesthetic. Gastric emptying was measured in the immediate postoperative period using paracetamol absorption. Paracetamol concentrations were measured by enzymatic assay method using a Beckman CX-7 automated analyser. The time to maximum concentration (Tmax) was statistically longer in the diamorphine group (control 41.8, SD 20.8 min; diamorphine 72.6 SD 41.9 min; p < 0.01). During the 2-h study period, mean morphine consumption via a patient controlled analgesia device was significantly higher in the control group (control 9.3, SD 3.6 mg; diamorphine 2.1, SD 2.1 mg; p < 0.01). We conclude that intrathecal diamorphine may contribute to the delay in gastric emptying that occurs immediately following elective spinal Caesarean section.