Effect Of Small Dose Of Naloxone On The Prevention Of Postoperative Complications Induced By Subarachnoid Morphine

Objective：To investigate the effects of intravenous injection naloxone (0.1mg) for theprevention of intrathecal morphine-induced postoperative complications(nausea,vomiting, pruritus, urinary retention).Methods: Sixty patients(20-40yr, ASA I or II) under combined spinal epiduralanesthesia(CSEA) for elective surgery were equally randomized into naloxone group (Agroup) and the control group (B group). All patients received spinal anesthesia at L3-4interspace.0.5%hyperbaric bupivacaine8mg and morphine0.2mg/2.5ml were injectedinto subarachnoid space at the speed of0.2ml/s and inserted catheter4cm cephaladwithin the lumbar epidural space. After the patients were place in supine position,sensory block level was adjusted between T6and T8. If the block level is not enough,2%lidocaine was given in epidural cavity. At the end of operation, epidural catheter wasremoved. All patients didn’t place urinary catheter before surgery. The amount of bloodlost was less than100ml and the volume of fluid transfusion was controlled less than1000ml during the operation. The patients in A group were intravenously injected ofnaloxone0.1mg/4ml every4h after surgery, equal volume of normal saline wereinjected in those of B group. The patients who can’t urinate or had urinary retention8h after surgery were inserted the catheter. When patients suffered severe nausea andvomiting after surgery, anti-emetics, tropisetron5mg was given. Visual analogscale(VAS), pruritus scores, the percentage of incidence of nausea, vomiting, uroschesisand respiratory depression was assessed respectively8h and24h after surgery.Results: The VAS8h and24h after surger was1.10±1.06and2.33±1.24in group A,was1.27±1.12and1.97±1.47in group B, there was not statistical significance betweentwo groups (P>0.05). The percentage of incidence of nausea, vomiting, pruritus anduroschesis in group A was significant less than those of group B. All patients did nothave respiratory depression.Conclusion: There are better postoperative analgesic effects and less consumption bysubarachnoid morphine than other ways, but there are more postoperative complications.interrupt intravenous low-dose of naloxone (0.1mg/4h) can prevent significantly sideeffects induced by subarachnoid morphine without reducing postoperative analgesiceffects.