Effect Of Low-dose Ketamine Via Epidural On The Analgesic Efficacy Of Patient-controlled Intravenous Analgesia With Morphine

Objective:To evaluate the effect of low-dose ketamine via epidural on the analgesic efficacy of patient-controlled intravenous analgesia with morphine.To evaluate the effect of low-dose ketamine with low-dose naloxone via epidural on decrease the adverse effect of analgesic morphine.Methods:Forty-five patients with ASA physical status I or II,both gender,BMI index ranged from 18-23kg/m~2,aged 25-60 year-old,undergoing selective operation of hepalobectomy were randomized into 3 groups:group C(0.9%NaCl,4ml into epidural);group K(0.1mg/kg ketamine, into epidural);group KN(0.1mg/kg ketamine+naloxone 20ug,4ml into epidural).Exclusion criteria included allergic to opioid,history of opioid abuse,spine malformation,abnormal hepatic function or renal function,unable to score senses,and blood loose greater than 500ml.Anesthesia was induced with propofol 2-3 mg/kg and fentanyl 4 ug/kg,maintained by sevoflurane 0.7-0.9MAC and 1%Lidocaine+0.2%decaine via epidural.After the operation and palinesthesia in the PACU,the PCIA with morphine was started and recorded.The analgesic efficacy was observed,including VAS,morphine consumption,and the adverse reaction of morphine(nausea,vomiting,itching) at the time point of 3hr,6hr,12hr,24hr.Results:Compared with group C,the morphine consumption was significantly lower in group K and group KN 6-hour,12-hour,24-hour after the start of PCIA.The VAS scores in group K and group KN were significantly lower than group C.The scores of adverse reaction in each were not significantly different.Conclusion:Low-dose ketamine via epidural can decrease the comsuption of morphine and enhance the efficacy of analgesia morphine.Low-dose naloxone with low-dose morphine can decrease the adverse effect compared with the low-ketamine alone.