Long current impulses may be required for nerve stimulation in patients with ischemic pain.
OBJECTIVE
To report on the efficacy of peripheral plexus catheters in the treatment of ischemic pain in spite of nerve stimulation with long current impulses.


METHODS
Two patients with severe neuropathic ischemic foot pain are described. A 56-yr-old man with diabetes, renal failure, and autonomic neuropathy presented with severe ischemic foot pain. Opioids produced excess sedation and hypotension. A 62-yr-old woman was admitted after femoral-popliteal bypass and developed a reperfusion pain syndrome not relieved with opioids, gabapentin, amitryptiline, and clonidine. In both patients, a sciatic plexus catheter was placed with resolution of pain. Conventional nerve stimulation, which uses a pulse duration of 0.1 msec, did not result in muscle contraction. However, by using a nerve stimulator capable of delivering a 1.0 msec impulse duration, a muscle twitch or paresthesia endpoint ensued allowing for successful catheter placement.


CONCLUSIONS
Peripheral plexus catheters provide a safe alter-native to systemic analgesics for pain relief in patients with ischemic foot pain. However, conventional nerve stimulation techniques may not elicit a motor response in patients with underlying neuropathy, and the use of nerve stimulators capable of delivering long current impulses is recommended.
Szerb
Jennifer
J
Department of Anesthesiology, University of Ottawa, Ontario, Canada.
Persaud
Desiree
D
D001342:Autonomic Nervous System Diseases / Q000150:complications; D003929:Diabetic Neuropathies / Q000150:complications; D004599:Electric Stimulation Therapy / Q000379:methods*; D005260:Female; D005268:Femoral Vein / Q000601:surgery; D005534:Foot Diseases / Q000628:therapy*; D006801:Humans; D007511:Ischemia / Q000150:complications*; D007676:Kidney Failure, Chronic / Q000150:complications; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology; D009407:Nerve Block; D010146:Pain / Q000188:drug therapy / Q000209:etiology; D059408:Pain Management; D010523:Peripheral Nervous System Diseases / Q000150:complications; D011152:Popliteal Vein / Q000601:surgery; D011183:Postoperative Complications / Q000628:therapy; D015427:Reperfusion Injury / Q000150:complications; D012584:Sciatic Nerve