COMPARISON OF PATIENT-CONTROLLED ANALGESIA WITH AND WITHOUT A BACKGROUND INFUSION AFTER LOWER ABDOMINAL-SURGERY IN CHILDREN

Forty children aged 6-12 yr undergoing appendicectomy were allocated r andomly to receive post-operative iv. morphine by a patient-controlled analgesia (PCA) system (bolus dose 20 mug kg-1 with a lockout interva l of 5 min) or the same PCA with a background infusion of morphine 20 mug kg-1 h-1. Patients breathed air and oxygen saturation was monitore d by continuous pulse oximetry. Scores for pain, sedation and nausea w ere recorded hourly. Patients with PCA + background infusion received significantly more morphine than those with PCA only. Both groups self -administered similar amounts of morphine using the PCA machine. There were no significant differences in the pain scores of the two groups. Patients with PCA + background infusion suffered more nausea (P < 0.0 1), more sedation (P < 0.05) and hypoxaemia (P < 0.001) than those wit h PCA only. They also had a better sleep pattern than those with PCA o nly.