comparison of 0.5% bupivacine alone versus 0.5% bupivacaine with verapamil as an adjunct in ultra sound guided supraclavicular brachial plexus block

Brachial Plexus block is a good alternative to general anesthesia for upper limb surgery. This type of anaesthesia mainly helps to achieve ideal operating conditions by producing muscular relaxation, maintaining stable intraoperative hemodynamic condition, sympathetic block and also reduces postoperative pain, vasospasm and oedema. This also avoids the unwanted effects  of general anaesthesia and the stress of upper airway instrumentation.

Regional nerve blocks are based on the concept that pain is conveyed by nerve fibres, which can be interrupted anywhere along their pathway. For upper limb Surgeries, Brachial plexus block is the preferred regional anaesthesia technique. Brachial plexus block at the supraclavicular level offers dense anaesthesia for surgical procedures at or distal to the elbow.

In the last decade image guided peripheral nerve block has become the norm for the anesthesiologist at the forefront of regional anaesthesia. Out of those dominant methods of imaging is the Ultrasonography. Ultrasound can determine the size, depth, and exact location of the brachial plexus and its neighboring structures. Real-time ultrasound imaging can help to guide the block needle to reach target nerves with fewer attempts. Under visual guidance, needle movement is purposeful and based on constant image feedback, thus avoiding nerve localization by trial and error.

Local anaesthetic administered for regional nerve blocks are utilized in providing post- operative pain relief in many surgical procedures by blocking signal traffic to the dorsal horn. Various local anaesthetics alone or in combination with different adjuvants have been tried to prolong the duration of postoperative analgesia for a long time but have met with limited success. Bupivacaine is a well‑established long‑acting regional anaesthetic, which like all amide anaesthetics has been associated with cardiotoxicity when used in high concentration or when accidentally administered intravascularly.

Now the challenge remains with the anaesthesiologists to prolong the duration of analgesia while minimizing adverse effects with singleshot brachial plexus block. Significant prolongation of brachial plexus analgesia is ideally accomplished with placement of continuous catheters. For moderate prolongation of analgesia (<24 h), various adjuvant drugs can be admixed with local anaesthetic. Therefore, investigators have tried mixing local anaesthetic with adjuvant drugs to prolong anaesthesia with nerve block. Adjuvants including epinephrine, clonidine, opioids, ketamine and midazolam have met but with limited success.

Verapamil, initially developed as a coronary vasodilator, is a phenylalkyamine type of calcium channel blocker. It selectively inhibits calcium influx through cellular membranes. . Calcium plays an important role in pain formation. Verapamil (calcium channel blocker) has been shown to have potent local anesthetic activity, reflecting inhibition of fast sodium channels. Other minor mechanism includes alpha-adrenergic blocking effect and in the neurons they block the neurotransmitter release.

This study will be conducted to compare Bupivacaine alone and Bupivacaine with verapamil in supraclavicular brachial plexus block with ultra sound guided technique.