Comparative evaluation between perineural magnesium sulphate and intravenous magnesium sulphate as an adjuvant to Ropivacaine in USG guided supraclavicular brachial plexus block.

PNB is the practical alternative to general anesthesia for surgery as it provides quality analgesia.

• In patients with profound co-morbidities such as severe respiratory disorders, cardiovascular diseases, morbid obesity and those with difficult airways where GA posses technical difficulty, PNB is a better alternative.In present anaesthesia practice to prolong postoperative analgesia use of various adjuvants is routinely done .

•Ropivacaine is an aminoamide local anesthetic that blocks the peripheral afferents acting on voltage dependent sodium channels.

•Magnesium is necessary for the presynaptic release of acetylcholine from nerve endings and may produce effects like calcium‑entry‑blocking drugs. Magnesium has long been used for its analgesic, antihypertensive, and anesthetic sparing effects.

•Magnesium sulphate is one of the widely used adjuvant used in different routes along with regional anaesthesia to prolong postoperative analgesia.

•Our current study was designed to compare  perineural magnesium sulphate and intravenous magnesium sulphate when used as an adjuvant with ropivacaine in supraclavicular block under USG guidance for upper limb surgeries.

•Method of data collection: A prospective randomized single blinded open study will be planned. In patients whom the block failed to act will be left out of the study.

On the day before surgery the patients will be attended and examined properly. A detailed medical and surgical history taken along with pre anaesthetic evaluation. Patients will be explained regarding the procedure and taught to interpret the visual analogue scale (VAS) (graded from 0 = no pain to 10 = maximum pain).  On arrival of the patient in the operation theatre, all standard ASA monitors connected .Intravenous line secured with 18G cannula in the unaffected limb and given I.V. fluids according to the requirement. The intravenous study drug, provided in the seal envelope, was started via a separate 20G intravenous cannula 30 minutes before brachial plexus block.

The patient will be placed in supine position with the head turned 45 degrees to the contralateral side. An ultrasound machine with a linear type of probe will be used. After skin preparation and local anesthetic infiltration of skin, the supraclavicular fossa scanned to locate the subclavian artery, first rib, pleura, and brachial plexus cluster, and then a 22-gauge, 5 cm, echogenic needle advanced from the lateral to medial in the long axis of the ultrasound beam. The needle advanced towards the ‘corner pocket’, where the lower trunk commonly lies in this area (between the subclavian artery medially, the first rib inferiorly and the plexus superiorly), and then half volume of prepared local anesthetic mixture either with saline or with 150 mg Magnesium was injected, then reposition the needle cranially toward the neural cluster in order to apply the remaining volume of local anesthetic just above and lateral to subclavian artery. During the intraoperative period, heart rate, blood pressures will be noted every 5 minutes (min) during the first 15 min., and then every 15 min. throughout the surgery. Inadequate sensory and motor blockade beyond 30 min following the infiltration of local aesthetics will be considered as an unsuccessful block.