Long current impulses may be required for nerve stimulation in patients with ischemic pain

Abstract

Purpose: To report on the efficacy of peripheral plexus catheters in the treatment of ischemic pain in spite of nerve stimulation with long current impulses. Clinical features: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 femoralpopliteal 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. Conclusion:Peripheral plexus catheters provide a safe alternative 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.Objectif : Présenter l'efficacité des cathéters de plexus périphéri-que utilisés dans le traitement de la douleur ischémique malgré la stimulation nerveuse avec de longues impulsions de courant.

Ultrasound-guided peripheral regional blockade in patients with Charcot-Marie-Tooth disease: a review of three cases

“…Use of higher current (> 1 mA) and a longer stimulation duration (> 0.3 msec) is recommended in these situations, but does not guarantee a successful block. 26 it has been suggested that local anesthetics may have an exaggerated effect on the spinal cord in the presence of demylination, 27 although this has not been confirmed in relation to peripheral nerve blocks. The patient described in case 1 had a chest wall deformity, and a good spread of local anesthetic around the axillary artery, was seen with a smaller volume requirement of local anesthetic.…”

Increased electrical nerve stimulation threshold of the sciatic nerve in patients with diabetic foot gangrene

“…26 Only a few case reports have been published that describe difficulties in identifying the sciatic nerve in diabetic patients by electrical nerve stimulation. [10][11][12] Sites et al 9 reported on two patients with ultrasound-guided popliteal fossa blocks who required a minimum current of 2.4 and 2.6 mA, respectively, to elicit a motor response of the sciatic nerve. Other authors, however, performed sciatic nerve blocks in diabetic patients and were obviously successful in localising the nerve by electrical stimulation, although the stimulation threshold was not reported.…”

“…Only a few case reports have been published indicating an alteration of the motor response of the sciatic nerve to electrical stimulation in patients at risk of peripheral neuropathy. [9][10][11][12] A systematic evaluation as to whether the electrical stimulation threshold for a motor response of the sciatic nerve is substantially increased in diabetic patients has not been carried out before. Eur J Anaesthesiol 2013; 30:435-440 Diabetic foot disease is a potentially disabling and lifethreatening complication that affects up to 25% of patients with diabetes mellitus.…”

A More Logical Sequence of Nerve Location When Performing Multiple-Injection Axillary Block

“…Grant and Coventry may seem more logical than the "modus operandi" I suggested, before writing the editorial, I looked at the published randomized studies of multiple-injection axillary block. In addition to my own studies (Koscielniak-Nielsen ZJ et al 1997, 1998, 1999ϫ 2, 2000, 2001, 2002, 2004, 2005 The nerve blocking sequence proposed by Drs. Grant and Coventry was used in 1 study (2001).…”