Analgesic Efficacy of Two Doses of Dexmedetomidine as Adjuncts to Lidocaine for Intravenous Regional Anesthesia

Intravenous Regional Anesthesia (IVRA) was first used by August Bier in 1908. This technique is easy to administer, reliable and cost-effective for short surgical procedures of the extremities performed on an ambulatory basis with success rate of approximately 95% - 100% . Lidocaine becomes the local anesthetic of choice for Intravenous Regional Anesthesia (IVRA) because of the lack of cardiac toxicity and neurotoxicity. But, delayed onset of action, poor muscle relaxation and lack of postoperative analgesia are the major limitations of this technique. Accordingly, many additives have been tried to overcome this problem. Muscle relaxants, ketamine,ketorolac, clonidine and opioids are examples of these adjuvants, and their effects have been studied in detail. An ideal anesthetic agent for IVRA should have rapid analgesic effect to reduce tourniquet pain and its effects should last longer enough after deflating tourniquet. To achieve this, other drugs including narcotics, nonsteroidal anti-inflammatory drugs, ketorolac, clonidine, nitroglycerin (TNG), dexmedetomidine, magnesium, and neostigmine were used in combination with lidocaine in different studies. This study aims 1- To compare the anesthetic and analgesic efficacy of Dexmedetomidine and lidocaine versus lidocaine only during IVRA (Bier's block) and 2-To compare anesthetic and analgesic efficacy of different doses of dexmedetomidine when used as adjuvants to lidocaine during IVRA (Bier's block).