[Comparison of the effects of lidocaine, lidocaine plus tramadol and lidocaine plus morphine for intravenous regional anesthesia].

OBJECTIVES: The aim of this study was to compare the effects of lidocaine alone and those of morphine or tramadol when added to lidocaine for intravenous regional anesthesia (IVRA) on tourniquet pain, the onset and regression time of motor and sensory block, the level and duration of analgesia, and analgesic consumption.

METHODS: After institutional approval and informed consent, 90 patients scheduled for forearm or hand surgery were enrolled and randomly assigned to one of three groups for administration of either 0.5% lidocaine (Group L), 0.5% lidocaine with 1.5 mg.kg(-1) tramadol (Group LT), or 0.5% lidocaine with 0.1 mg.kg(-1) morphine (Group LM) in a volume of 40 ml. The onset and duration of sensory and motor blocks, duration of analgesia and proximal and distal tourniquet, time to first pain medication, visual analog scale (VAS) scores, analgesic requirements in 24 hours, vital signs, and side effects were recorded.

RESULTS: Sensory block onset time was significantly shorter in Group LM compared with the other groups and also in Group LT compared to Group L. In addition, sensory block regression time was significantly shorter in Group L than in Group LM (p<0.05). There was a significant increase in VAS scores at the postoperative 4th and 5th hr in Group L (p<0.05). Mean arterial blood pressure was significantly reduced in Group LM at the time of tourniquet deflation (p<0.05).

CONCLUSION: IVRA with lidocaine and morphine or tramadol improves postoperative analgesia and sensory block. However, these combinations provide no advantage on tourniquet pain, motor block quality, analgesia duration or analgesic consumption.