INTRAVENOUS KETAMINE OR FENTANYL PROLONGS POSTOPERATIVE ANALGESIA AFTER INTRATHECAL NEOSTIGMINE

The purpose of this study was to determine whether intravenous (IV) ke tamine would enhance analgesia from intrathecal (IT) neostigmine compa red with combining IV fentanyl with IT neostigmine. Sixty patients und ergoing vaginoplasty under spinal anesthesia were assigned to one of s ix groups (n = 10). Patients were premedicated with midazolam plus the IV test drug. The IT drugs were 20 mg bupivacaine plus saline or 50 m u g neostigmine. The control group (CG) received saline IV and IT. The neostigmine control group (NCG) received saline IV and neostigmine IT . The ketamine group (KG) received ketamine 0.2 mg/kg IV and saline IT , and the ketamine neostigmine group (KNG), ketamine IV and neostigmin e IT. The fentanyl group (FG) received fentanyl 1 mu g/kg IV and salin e IT, and the fentanyl neostigmine group (FNG), fentanyl IV and neosti gmine IT. The time to first rescue analgesic was longer for the FNG an d KNG compared with the CG, with less rescue analgesic consumption (P < 0.02 and P < 0.01, respectively). Only the FNG had significantly int raoperative nausea/vomiting (P < 0.02). In conclusion, the combination of IV ketamine and IT neostigmine results in prolonged postoperative analgesia and less intraoperative nausea and vomiting than the combina tion of IV fentanyl and IT neostigmine.