Comparison of Two Methods of Intravenous Administration of Morphine for Postoperative Pain Relief

Morphine sulphate was used for the control of pain following major abdominal surgery for a period of three days either as patient-controlled or continuous infusion. The two groups of patients were comparable with regard to patient and operation details, duration of infusion, pain scores and complications. The only significant difference was a reduced dose requirement of morphine in the patient-controlled analgesia group (P less than 0.005). Some possible explanations for this finding are given. It is suggested that a properly supervised continuous infusion of morphine is as good as patient-controlled administration. There was a negative correlation between the age of the patient and the dose of morphine used.