After institutional review board approval (IRN NO: 631/2016) and written informed consent from patient, this prospective randomized double-blinded clinical trial is being carried out in 100 patients. After thorough preanaesthetic evaluation patients are allocated into two groups according to inclusion and exclusion criteria. Patients are randomized to one of the two groups of 50 patients each by computer generated random number sequence.

Group N (n = 50) – Bupivacaine(0.5%) 25 cc + Nalbuphine 20 mg diluted upto 5 ml of normal saline

Group C(n = 50) –  Bupivacaine(0.5%) 25 cc + 5 ml normal saline

In preanaesthetic preparation Room, standard monitoring for Heart Rate (ECG), Mean arterial blood pressure (NIBP), Peripheral oxygen saturation (SpO2) are established and baseline vital parameters are recorded. Patients are educated for subjective reporting of pain using 10 points visual analogue scale (VAS) where ‘0’ represents no pain and ‘10’ represented the worst pain possible. An appropriate size i.v. Cannula is secured and DNS infusion is started slowly. Injection Ondansetron 0.08 mg/kg is given as premedication 15 minutes before induction. In the preoperative preparation room only, patients are randomized to one of the two study groups by computer generated random number sequence. The doctor performing the randomization, prepared the solution as per the group assigned and no other member of the research team knows about the contents of the solution. In the operation theatre, we perform supraclavicular brachial plexus block with the aid of Nerve locator (B. BRAUN Company). After giving the position for supraclavicular brachial plexus block, a 22G short beveled 1.5 inch insulated needle is introduced just lateral to subclavian artery pulsation 1 cm above the mid-point of clavicle and advanced in backward, inward and downward direction. The current is initially set to deliver 0.5 milliamperes (mA) at 2Hz stimulation frequency. The needle is advanced till we get contraction of forearm muscle. Once the contraction is seen, current is reduced in 0.02 mA decrements while advancing the needle till we get maximum contraction with minimum possible current. At this point, the solution as per the group assigned is injected after careful aspiration so as to avoid intravascular injection of drug.The doctor performing the block is unaware of the drug combination administered. End of the injection is taken as Time ’0’. Immediately after the block, sensory and motor characteristics of blockade, hemodynamic variables, SpO2 are assessed by the same doctor who performs the block at 1, 3, 5, 10, 15, 30 minutes,1 hour, 2 hour, 3 hour, 4 hour and then at two hourly interval for 24 hours. Post operatively the time of first rescue analgesic required at visual analouge score 4 and total analgesic doses given in 24 hours are noted. Diclofenac sodium 1.5 mg/kg i.v. is given as rescue analgesic whenever required (VAS=4).Any complication or adverse event are also noted down. Bradycardia is defined as heart rate <60/min and is treated by inj. Atropine intravenously. Variation in mean arterial pressure 30% on either side of baseline is considered significant and treated accordingly.