Removal of a knotted stimulating femoral nerve catheter using a saline bolus injection

Abstract

ObjectiveStimulating peripheral nerve catheters have become increasingly popular as part of postoperative multimodal analgesia for total knee arthroplasty. We describe a case of a successful nonsurgical removal of a knotted stimulating femoral nerve catheter after saline expansion of the catheter pocket at the bedside.Case reportA 65-year-old female underwent total knee arthroplasty under combined spinal epidural anesthesia. Postoperatively, a stimulating femoral nerve catheter was placed without complication. The catheter was threaded 12 cm past the needle tip with minimal resistance. Function of the catheter was verified by loss of pinprick sensation in the femoral nerve distribution and excellent analgesic efficacy was achieved. The first attempt at catheter removal was unsuccessful. Thigh flexion and rotation also failed to facilitate catheter removal. The catheter was then left to continuous tension for 6 hours, but further attempts at removal remained unsuccessful. Under ultrasound visualization, 10 mL of saline was injected through the catheter with moderate resistance and without patient discomfort, after which the catheter was removed using minimal tension. The catheter was intact but had a single knot at the distal end of the catheter.ConclusionsWe present a rare case of a knotted stimulating catheter in which the use of a saline bolus to dilate the catheter pocket proved to be successful after other simple methods of catheter removal had failed. Given the simple nature of this technique, it can be attempted at the bedside before more invasive procedures are planned.

Effect of Arm Positioning on Entrapment of Infraclavicular Nerve Block Catheter

“…Previous studies described injecting saline through the catheter, to aid in unkinking the catheter or localizing its position in the patient [ 5 ]. This was not possible in our case, since the entire catheter body was removed.…”

“…We were also unable to visually assess the depth, as there were no depth markings. Excessive catheter advancement has been cited as a cause for difficult catheter removal [ 5 ]. The catheter in this case was threaded 5 cm beyond the needle tip without resistance and without moving the needle in the process.…”

Use of Ultrasound Guidance to Remove Entrapped Stimulating Popliteal Catheters

“…A similar technique has also been used to facilitate removal of a knotted femoral nerve catheter that had become entrapped, theoretically by expanding the area just below the fascia iliaca with 10 mL of saline. Th is increased area allowed for easy removal of the knotted catheter ( 6 ). In addition, the portability and simplicity of most ultrasound machines allows for additional fl exibility.…”

Removing a trapped epidural catheter: Concerns

“…to remove the catheter. [ 3 4 ] Although the authors have not mentioned how much the length of the catheter increased with stretching, but excessive stretching could increase the chances of catheter breakage. The force applied during removal of the trapped catheter should be the least, and various manoeuvres have been described to ease the removal of catheter without undue force.…”

“…[ 3 ] Patient's position manipulations are the most frequently attempted initial methods to free entrapped catheters. [ 4 ] The flexion of spine in lateral decubitus position may ease the removal of catheter. [ 5 ] If it is suspected that a knot has formed, some authors have suggested using a small and steady force for withdrawal (but not multiple attempts), to stop pulling if the catheter begins to stretch too much (not reported by the authors in this case report), placing the patient in various positions (e.g., the same position as on insertion, the lateral decubitus position and a flexion or extension position) (again not described by the authors) and injecting normal saline through the catheter (not used by the authors).…”