Small Dose of Midazolam Added to Fentanyl-Ropivacaine for Patient Controlled Epidural Analgesia after Subtotal Gastrectomy

ABSTRACT

BACKGROUND: Midazolam has been reported to have a spinally mediated antinociceptive effect. In this randomized, double-blind study, we evaluated whether a small dose of midazolam added to fentanyl-ropivacaine mixture for PCEA (patient controlled epidural analgesia) improves epidural analgesia in patients underwent elective subtotal gastrectomy. METHODS: Forty five patients, ASA physical status I and II, undergoing subtotal gastrectomy were randomly allocated to receive 0.2% ropivacaine mixed with fentanyl 4microg/ml or 0.2% ropivacaine mixed with fentanyl 4microg/ml and midazolam 0.2 mg/ml. The infusion rate was set to deliver 4 ml/hr of the study solution, with a bolus of 2 ml per demand and a 20 minutes lockout time. RESULTS: Infused volume (P < 0.05) and VAS scores (P < 0.05) was significantly lower in the patients receiving midazolam. However, there were no differences in requiring rescue analgesics, PONV (postoperative nausea and vomiting), sedation scores, urinary retention, and pruritus between groups. CONCLUSIONS: Small dose of midazolam could augment analgesia without adverse effects when added to thoracic epidural infusion of fentanyl and ropivacaine.