A comparison of equal volumes of a mixture of 0.5% Bupivacaine (+ adrenaline 1:200,000) with 1% Lignocaine; and 0.375% Ropivacaine for Axillary Brachial Plexus Anaesthesia

INTERVENTION: The patients will be randomly assigned to one of two groups: GROUP M will receive the mixture of 0.5% Bupivacaine (+ Adrenaline 1:200,000), 20 ml, with 1% lignocaine 30 ml (400 mg total). GROUP R will receive 0.375% Ropivacaine, 50 ml (187.5 mg total). A blind observer then will assess sensory and motor block. The sensory block assessment in keeping with previous research will be performed with a short beveled, 23‐gauge needle in the innervation areas of the median n. radial n. ulnar n. and musculocutaneous n. and compared to the opposite side. (0 = no block, 1 = loss of sensation to pinprick, 2 = loss of sensation to touch). The degree of motor block will be tested by thumb abduction (radial n), thumb adduction (ulnar n), thumb opposition (median n.) and flexion of the elbow in supination and pronation of the forearm (musculocutaneous n.). (0 = no block, 1 = partial motor block, 2 = complete motor block). The assessment of the sensory and motor block will be made at 5, 10, 15, 20, 30 and 40 min intervals following the completion of the local anaesthetic (LA) injection. It will also continue at 60 min intervals following the cessation of surgery, until either the block has disappeared or the time is midnight and the patient will need to sleep. The time needed for each patient to be ready for surgery (= a grade 1 block for both sensory and motor testing in all areas) will also be recorded. Surgery will be able to start if either pinprick testing reveals analgesia in all areas, or at 50 min if the region to be operated on is adequately analgesed. If adequate analgesia does not occur by 50 min, the block may be supplemented with a peripheral local infiltration of 1% Lignocaine by the Surgeon. Should the block still not be adequate, then the patients will receive a general anaesthetic and be excluded from the trial. Intra‐operatively, if the patient feels any discomfort, further sedation and intravenous (iv) fentanyl will be administered and recorded. Also, any iv CONDITION: Surgery: Anaesthesia ; Surgery PRIMARY OUTCOME: Degree and quality of local anaesthetic blocks in two groups of patients. SECONDARY OUTCOME: Not provided at time of registration INCLUSION CRITERIA: 1. American Society of Anesthesiologists (ASA) I ‐ III 2. Age above 16 years, weight between 60 ‐ 100 kg and height above 150 cm