الفهرس 
Aim of The WorkOnly 14 pages are availabe for public view
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Abstract
or damage stimuli associated with a physiological changes via the sympathetic nervous system, neuroendocrine system And immune system Stimulation. So blood pressure, heart rate is elevated, release of mediator such cortisol, adrenaline, noradrenaline, cytokine and growth factor may occur, moreover, psychological effect as fatigue, anxiety are associated. To decrease these signs several methods done intra-operative as well as postoperative, such as opioid, non steroidal anti-inflammatory drugs administration and regional anesthesia (1).
Regional anesthesia could use alone or as an analgesic element in intra-operative or postoperative with the advantages of remarkable reduction of postoperative pain and nausea that allow early patient recovery and rapid discharge (1).
Several approaches for regional anesthesia (central anethesia) have been described as epidural, paravertebral, spinal anesthesia for lower limb or abdominal and pelvic surgeries and peripheral nerve block as brachial plexus block, interscalene, infraclavicular, supraclavicular and axillary approach block can serve as adjuvant for general anesthesia or used alone in upper limb surgeries, sciatic and femoral for lower limb surgeries (2).
The mechanism of action of neuroaxial anesthesia is by inhibiting transmission of nociceptive from the peripheral to central nervous system. But the anesthetic and analgesic effect of this group might be limited due tothe short life of local anesthetic drugs (2).
This disadvantage could overcome by increasing the dose of local anesthetic drugs,which carried the risk of systemic complications and neurotoxicicty, or synergism of the action of local anesthetic drugs by adjuvant drug (3).
Several adjuvant drugs have been used in neuroaxial nerve block as opioids, dexamethasone, ketamine, magnesium sulphate and midazolam to prolong the postoperative analgesia (4).
Bupivacaine is an amino-amide anesthetic, more stable and less likely to cause allergic reactions. It is one of well established local anesthetic agent with prolonged action, but often associated with cardiotoxicicty with high concentration or when administrated intravenous (5).
It is indicated for local infiltration, peripheral nerve block, sympathetic nerve block, and epidural and caudal blocks. It is sometimes used in combination with epinephrine to prevent systemic absorption and extend the duration of action (6).
Nalbuphin derived from 14-hydroxymorphine, is considered a potent analgesic possessing a mixture of k agonist and μ competitor profiles. The pain-relieving potency considering nalbuphine had been reported to be identical to morphine, but dissimilar from it in exhibiting a top limiting effect on respiratory depression. Nalbuphine possesses the effect of maintaining or even augmenting the opioid μ receptor centered analgesia and at the same time mitigating the μ-opioid side effects. Also, it had been used successfully and safely in epidural and intrathecal blocks (7).
Dexmedetomidine (DEX) is a highy selective alpha2 adrenergic receptor agonist, it is well known a clinically used analgesic, in addition it shows synergism with regional anesthesia and better post operative pain control. also for neuroaxial DEX produces antiception through inhibition of spinal microglia and astrocyte (8).
Dexmedetomidine might be a good adjuvant drug in neuroaxial anesthesia and analgesia, it decreases the consumption of the anestetietic drugs intra and postoperative, also it prolongs the postoperative analgesic duration, in addition the facilitatory effect of neuroaxial and peripheral nerve block, but risk of bradycaridia, hypotension and neurotoxicity should be considered (9).
It was advocated that supraclavicular approach is preferable because of its rapid onset, reliable anesthesia and safety. which is suitable for any surgeries of upper limb except that involving the shoulder (2).
Anatomical description and landmarks of brachial plexus should be considered for successful technique of supraclavicular block, the brachial plexus is a complex system of nerves, and they come out of the neck, divided into 5 roots, upper, middle and lower trunks, which divided into six division to form 3 cords(medial, lateral and posterior) which terminated into major nerves which supply the upper limb. Brachial plexus and subclavian artery is related to each other and the pleura of the lung at the level of the 1st rib.
The brachial plexus is located lateral and posterior to the subclavian artery. The subclavian vein and anterior scalene muscle are found medial to the subclavian artery. The pleura is usually situated within 1-2 cm from the brachial plexus, ultrasound can be a useful tool for identification and defferentiation between different structures while approaching the bracial plexus block (3).