Reactions 1130 - 2 Dec 2006

SRopivacaine

Peripheral nerve disorders after continuous femoralblock in an elderly patient: case report

Peripheral nerve disorders occurred in a 72-year-old manafter continuous femoral block with ropivacaine. He was laterfound to have a preexisting subclinical peripheral nervedisorder.

The man underwent left total knee arthroplasty withcontinuous femoral nerve block, sciatic nerve block and spinalanaesthesia. He received 30ml ropivacaine 0.5% injectedslowly through the femoral catheter and 20ml ropivacaine0.5% slowly injected for sciatic nerve block. Spinal anaesthesiawas achieved with bupivacaine. After the uneventful150-minute surgery, ropivacaine 0.2% was given continuouslythrough the femoral nerve catheter at a rate of 10 mL/h forpostoperative analgesia; this infusion was stopped 48 hourslater and the femoral catheter was removed 6 hours later. Atthis time, persistent weakness of the left quadriceps wasdetected along with hyposensitivity in the medial aspect of thethigh, and an absent patellar tendon reflex. On postoperativeday 4, electrophysiological investigations revealed denervationin the medial vastus muscle, with similar findings in the rightlimb, consistent with a pre-existing peripheral nerve disorder.Six weeks after surgery, repeat investigations revealed a partiallesion of the femoral nerve indicating worsening of his existingperipheral nerve disorder.

The man was discharged on postoperative day 9 withpersistent weakness of the left quadriceps muscle,hyposensitivity of the medial aspect of the thigh, and absentpatellar tendon reflex. Complete sensorimotor recovery of theleft quadriceps muscle was noted at follow-up 6 months later.

Author comment: "[A]lthough 0.5% ropivacaine is usuallynot neurotoxic, the underlying neuropathy of our patient mayhave contributed to make the femoral nerve more susceptibleto the potential neurotoxic effect of continuous localanesthetic infusion."Blumenthal S, et al. Preexisting subclinical neuropathy as a risk factor for nerveinjury after continuous ropivacaine administration through a femoral nervecatheter. Anesthesiology 105: 1053-1056, No. 5, Nov 2006 -Switzerland 801026844

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Reactions 2 Dec 2006 No. 11300114-9954/10/1130-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved