Identification of location of nerve catheters using pumping maneuver and M-Mode-a novel technique.

BACKGROUND Optimum positioning of the nerve catheter is crucial for a successful nerve block. We present a novel technique for confirmation of catheter position. METHODS We are describing a novel technique for localization of the shaft and tip of the peripheral nerve catheter. After introduction of the catheter 3 to 5 cm beyond the needle tip and removal of the needle, the guide wire was reintroduced and was moved inward and outward rapidly. This movement produced the color Doppler effect along the track of the catheter and the catheter tip that helped us verify the proper positioning of the catheter. RESULTS We used our technique in a cadaveric study for bilateral supraclavicular brachial plexus block, followed by a series of 5 patients undergoing femoral, sciatic (anterior approach), popliteal (2 patients), and brachial plexus blocks. Catheters were also identified on M-Mode sonography during pumping maneuver and during the injection of medications. CONCLUSION Pumping maneuver and M-Mode can be additional tools in the array of modalities applied to verify proper positioning of a nerve catheter.