1. A COMPARISON OF THE DURATION OF BRACHIAL PLEXUS BLOCK BETWEEN ULTRASOUND GUIDED AND NERVE STIMULATOR TECHNIQUES IN ELECTIVE SHOULDER SURGERY A. Smith 1, P. Kumara 1, K. Ismail 2 1 Anaesthetics Department, Dewsbury & District Hospital, Dewsbury, West Yorkshire, United Kingdom. 2 Anaesthetics Department, Spire Elland Hospital, Elland, West Yorkshire, United Kingdom. Background References Objectives The aim of this prospective study was to compare the duration of brachial plexus blockade between ultrasound guided and nerve stimulator techniques. ConclusionResults 1.McCartney CJL, Lin L, Shastri U. Evidence basis for the use of ultrasound for upper-extremity blocks. Regional Anaesthesia and Pain Medicine. 2010; 35; S10-15. 2.Liu, SS, Ngeow, J, John, RS. Evidence Basis for Ultrasound-Guided Block Characteristics:Onset, Quality, and Duration. Regional Anesthesia & Pain Medicine. 2010; 35; S26-35 3.Bruce BG, Green A, Blaine TA, Wener LV. Brachial plexus blocks for upper extremity orthopaedic surgery. Journal of the American Academy of Orthopaedic Surgeons. 2012; 20 (1); 38-47. A total of 46 subjects undergoing elective arthroscopic shoulder surgery for either subacromial decompression or acromioclavicular joint stabilisation were randomized to either the ultrasound guided or nerve stimulator group for interscalene brachial plexus blockade. All subjects received local infiltration of 30mls of 0.25% levobupivicaine. All 46 interscalene blocks were performed by a single operator. Duration of block, adjusted to the nearest fifteen minutes, was determined from follow up data. Methods Brachial plexus blockade provides safe and reliable anaesthesia and postoperative analgesia for upper limb surgery. It may be used alone or in combination with general anaesthesia. It is therefore particularly useful in patients with significant co-morbidities. Ultrasound guidance improves the quality and speed of block onset 1. This technique has become increasingly favoured over the neuro- stimulation technique. Systematic review found that 17% of RCTs reported a longer duration of block with ultrasound 2. Brachial plexus blockade can significantly reduce postoperative pain, allowing earlier rehabilitation and reducing opioid requirements 3. The use of ultrasound allows the user to visualise t he path of the needle and the close proximity of the needle to the roots of the plexus. This ensures that the majority of the volume injected spreads close to the nerve roots and allows vital structures to be avoided, thereby providing a more effective block and potentially reducing the risk of complications. The results of this study demonstrate a significantly longer duration of brachial plexus blockade following infiltration of 30mls of 0.25% levobupivicaine with the use of ultrasound guidance in comparison to the nerve stimulator technique. It is recommended that less volume is used if an ultrasound guided technique is to be used since it is superior in producing a successful block. Data was collected from 23 subjects from each group. The age of subjects in the ultrasound guided group ranged from 23 to 72 years. The age of subjects in the nerve stimulator group ranged from 19 to 77 years. The mean age of subjects in both groups was 43 years. In the ultrasound guided group, the duration of block ranged from 225 to 2160 minutes, with a mean of 596 minutes. In the nerve stimulator group, the duration of block ranged from 195 to 510 minutes, with a mean of 322 minutes. The mean difference between the two groups was 275 minutes (95% confidence intervals 73.1 - 475.2 min, unpaired students t-test p=0.0087).