Influence of Ketamine and Midazolam on the Analgesic Effect of Epidural Bupivacaine and Fentanyl after Low Abdominal Surgery / 대한통증학회지

ABSTRACT

BACKGROUND: There are many ways to provide superior analgesia for postoperative pain after abdominal surgery of which epidural analgesics with opioids and local analgesics are the most useful. In an effort to maximize the level of analgesia and to minimize the side effects, ketamine, midazolam, clonidine, and adrenalin can be co-administrated as an adjuvant. This study examined the analgesic effect and side effects of midazolam compared with those given an epidural injection of bupivacaine, fentanyl and ketamine. METHODS: In a double blind randomized controlled trial, 50 patients received either fentanyl 0.3 microgram/kg/h and ketamine 0.1 mg/kg/h (Group FK) or fentanyl 0.3 microgram/kg/h, ketamine 0.1 mg/kg/h and midazolam 0.4 mg/h (Group FKM), added to 0.125% of bupivacaine at a rate of as much as 2 ml/h, for patient controlled epidural analgesia (PCEA) after low abdominal surgery. Ten minutes before surgery, the patients received either 10 ml of 0.125% bupivacaine with 0.5 mg/kg of ketamine or 10 ml of 0.125% bupivacaine with the same amount of normal saline, added to fentanyl 50microgram. The pain score and the side effects were recorded at 1, 3, 6, and 24 hours after surgery. RESULTS: There was no difference in the pain score except for the VAS on coughing 1 hour after surgery. FKM group had fewer side effects. CONCLUSIONS: There was a better analgesic effect and fewer side effects with the addition of epidural midazolam to bupivacaine and fentanyl with ketamine formula. However, more study on the dose and route of administration will be needed.