Infraclavicular Catheters Case Study

Infraclavicular brachial plexus catheters provide intraoperative anaesthesia as well as control post-operative pain [1]. Anaesthesiologists use ultrasound (US) with or without peripheral nerve stimulation (PNS) for the placement of these blocks.
When comparing the two modes of placement, most authors have looked at performance time and success in single injection blocks with small sample size [2-5]. We do not know if either technique alone improves success when used to place infraclavicular catheters. We designed this study to test the primary hypothesis that placing infraclavicular catheter using US guidance alone improves block success when compared with PNS guidance. Secondary hypotheses included reduced procedure time and better patient satisfaction with US guided infraclavicular catheter placement.
METHODS
We performed this prospective,
The point of needle entry was two cm medial and two cm inferior to the marked coracoid process. The direction of needle was perpendicular to the surface on the horizontal-supine patient. We used a peripheral nerve stimulator (PNS) (Pajunk®Geisingen, Germany) with a 0.6 mA current output and a progressive decrease and disappearance at 0.2mA (pulse width 0.1 ms, frequency 2Hz) to locate the brachial plexus. We aimed for motor responses in the posterior cord or combined posterior and lateral cord territory. Injection of 1-2 ml of D5W created a potential perineural space without abolishing neurostimulation. This technique has been described earlier [8]. Using PNS and maintaining the evoked motor responses, we advanced a stimulating catheter, 1–2 cm beyond the needle tip. If the responses disappeared, we removed the catheter, re-confirmed the motor response with the needle and then reintroduced the catheter. Delivery of the entire dose of mepivacaine was through the catheter in five ml aliquots and dressing applied, as described