PATIENT-CONTROLLED ANALGESIA WITH LOW-DOSE BACKGROUND INFUSIONS AFTER LOWER ABDOMINAL-SURGERY IN CHILDREN

Forty-five children (aged 6-12 yr) undergoing appendicectomy received one of three analgesic regimens using patient-controlled analgesia (PCA) with morphine: no background infusion (B0); background infusion 4 mug kg-1 h-1 (B4); background infusion 10 mug kg-1 h-1 (B10). Total consumption of morphine was greater in group B10 compared with groups B0 (P < 0.01) and B4 (P < 0.05). There was no significant difference in morphine consumption in groups B0 and B4. All three groups self-administered similar amounts of morphine and there were no significant differences in pain scores or incidence of excessive sedation. Group B4 suffered less hypoxaemia compared with groups BO (P < 0.01) and B10 (P < 0.001). Group B10 suffered more nausea and vomiting than groups BO (P < 0.001) and B4 (P < 0.001), but there was no significant difference in the incidence of nausea and vomiting between groups BO and B4. Groups B4 and B10 spent more time at night asleep than group BO (P < 0.05). There were no significant differences between the groups in the amount of time spent asleep during the day. Inclusion of a background infusion of morphine 4 mug kg-1 h-1 in a PCA regimen for children did not increase the incidence of side effects and was associated with less hypoxaemia and a better sleep pattern than no background infusion.