Use of ultrasound guidance and contrast enhancement: a study of continuous infraclavicular brachial plexus approach

Purpose: We describe our experience of combining the use of ultrasound (US) guidance with contrast enhancement and peripheral nerve stimulation for the insertion of infraclavicular brachial plexus catheters. Methods: Thirty patients scheduled to have upper limb surgery under regional block were studied. Under US guidance and peripheral nerve stimulation assistance, continuous peripheral nerve block needle and stimulating catheter were placed in the infraclavicular area. Needle and catheter tip location was confirmed with agitated 5% dextrose and seen under colour Doppler with US before injecting local anaesthetic (LA). Patients were evaluated in terms of onset times and efficacy of block. Post-operatively, on block recession a catheter was stimulated and visualization of spread of LA during injection through the catheter was done. Secondary block (subsequent to re-injection of LA) was assessed. Patients were followed-up for a week. Results: Mean time to onset of block was 19.7 (+/- 4.9) min. There were no incomplete blocks and all components of the plexus were blocked completely. Post-operatively, in 95.7% of patients, the spread of hand-agitated LA via the catheter could be seen by color Doppler with ultrasonography. All patients had excellent post-operative analgesia and high degree of satisfaction. There were no complications. Conclusion: Contrast enhancement with US guidance during infraclavicular brachial plexus block enables direct visualization of needle and catheter tip location. Our early experience suggests that this leads to successful initial and subsequent post-operative block. Further controlled studies are needed to compare this technique with more prevalent and conventional techniques of catheter insertion.