Comparison of Effect Between Preincisional and Postoperative Administration of Intravenous Ketamine 0.15 Mg/Kg on Postoperative Morphine Analgesic Requirement in Patients Underwent Lower Limb Orthopedic Surgery

Background: Ketamine has been a component of perioperative analgesia for years. However its most effective administration method is still unclear.\ud Objective: This study aimed to know the effect of ketamine administration during preincisional. intraoperative, and 24 hours postoperative period compare with ketamine during 24 hours postoperative period to postoperative morphine requirements.\ud Methods: This is an experimental research using double blind random technique. Total sample 50, which divided into 2 groups which underwent lower limb orthopedic surgery with spinal anesthesia. First group get preincisional IV ketamine 0.15 mg/kg + 0.1 mg/kgBW during surgery and 24 hrs postoperatively; and second group get postoperative IV ketamine 0.15 mg/kg + 0.1 mg/kgBW 24 hrs postoperatively.\ud Both groups get morphine as postoperative analgesia via patient-controlled analgesia device with 2 mg loading dose, I mg bolus dose, and 7 minutes lockout interval. Time to first postoperative morphine administration was measured from the end of surgery to the time of morphine loading dose administration on patient's demand; postoperative morphine consumption was counted within 24 hours.\ud Result: Neither time to first analgesic administration nor morphine consumption within 24 hours were significantly different between two groups.\ud Conclusion: Ketamine has no preventive analgesia effect in patients undergo spinal anesthesia