The efficacy of adding a continuous intravenous morphine infusion to patient-controlled analgesia (PCA) in abdominal surgery

Abstract

The effect of adding a continuous infusion of morphine 1 mg/hr to patient-controlled intravenous analgesia was studied in a randomized double-blind trial. Ninety-six patients scheduled for abdominal surgery were enrolled; 38 received PCA and continuous infusion (PCA + C), 45 received PCA alone and 13 were excluded because of protocol violations. PCA was delivered via an ABBOTT 4200 pump with settings of morphine 1 mg bolus and five-minute lockout in both groups. A separate pump delivered a continuous infusion of morphine 1 mg/ml (PCA + C) or 9% normal saline (PCA) at 1 ml/hr for three postoperative days. Pain was assessed by hourly verbal pain scores (VPS) and daily visual analog pain scores..