Patient controlled analgesia in children and adolescents: a randomized controlled trial

In children, patient controlled analgesia (PCA) and continuous infusion (CI) of morphine are well established methods of relieving postoperative pain. This study was designed to assess the efficacy of PCA plus background infusion (BI) (15 microg x kg(-1) x h(-1) and bolus doses of 15 microg x kg(-1) with a lock-out interval of 10 min) with CI (20 to 40 microg x kg(-1) x h(-1)) in terms of analgesia, morphine needs and side-effects. A stratified randomized controlled trial was carried out. 47 children aged 5-18 years undergoing major elective lower/upper abdominal or spinal surgery were allocated. The magnitude of surgery was assessed by the Severity of Surgical Stress scoring (SSS) system. Pain was assessed by self-report every three h. Side-effects compatible with morphine as well as morphine consumption were recorded. Morphine consumption was significantly increased in the PCA group compared with the CI group. Moreover, morphine consumption was associated with SSS, independent of the technique of administration. There were no significant differences between groups in pain scores or in the incidence of side-effects.