Ultrasound-guided supraclavicular block for upper extremity surgery has a high degree of analgaesic efficacy postoperatively, according to the results of a retrospective study presented at the 2014 Annual Meeting of the American Society of Anesthesiologists (ASA).
Supraclavicular block using ultrasound-guided technique successfully controlled 4-hour postoperative pain in 94% of procedures evaluated in this study of the records of 259 patients, noted lead author and anaesthesiologist Warren J. Choi, MD, Dallas, Texas speaking here on October 12, on behalf of colleagues from University of Texas Southwestern Medical Center, Dallas. The researchers evaluated 12-month post-operative data of patients who received an ultrasound-guided supraclavicular block for upper-extremity surgery at their teaching institution.
For each patient, a high-frequency linear probe (suitable for visualising more superficial structures) was used to provide real-time ultrasound guidance for the block. The neurovascular structures were imaged on short axis, and the needle was inserted using an in-plane technique (insertion at the side of the probe rather than away from the probe allows the entire shaft of the needle to be visualised and tracked). Still guided by ultrasound, the block needle was then placed near the brachial plexus.
Midazolam and fentanyl were used for sedation, and 25 to 30 mL of 0.5% ropivacaine was injected in 5 ml aliquots.
The quality of post-operative analgaesia was determined by comparing pain visual analog scores (VAS) immediately after surgery and 4 hours postoperatively. The time of the first analgaesic request within a 4-hour postoperative period was also recorded. The researchers used VAS scores as the primary outcome.
Adequate post-operative pain was defined as a score < 3 (0 = no pain, 10 = unbearable pain) and no requests for pain medication. Fifteen patients reported scores between 3 and 10, requiring supplemental analgaesic treatment within 4 hours post-operatively. The time to first analgaesic request was 146 ± 48 minutes (mean ± SD).
Advances in neuronal blockade, such as the use of ultrasound and long-acting local anaesthetics, have improved the safety and success rate of peripheral nerve block. The acute-pain services that major medical institutions can provide have greatly increased patients’ postoperative comfort and satisfaction, the authors concluded.