THERAPY

-Tracey Taylor-

Chemical neurolysis has a place in the treatment of chronic nonmalignant pain in patients who have failed to respond to other treatments, according to Dr AR Abadir and colleagues from Brookdale University Hospital and Medical Center, New York, US. This conclusion came from the results of a study presented at an International Symposium on Regional Anaesthesia [Aucklan~ New Zealand; Apri~ 1996]. It reflects the current opinion among pain specialists that neurolytic procedures have an important role in the management of nonmalignant pain associated with carefully selected conditions.

There are few absolute contraindications to the use of neurolysis as a treatment for malignant pain. In contrast, the adverse effects and complications associated with the procedure mean that it should only be used in selected cases of nonmalignant pain [see boxed text].

Speaking during a plenary session, Professor Michael Stanton-Hicks from the Pain Management Center at the Cleveland Clinic Foundation, Ohio, US, saidthat there must be a clear argument for using neurolysis in nonmalignant pain and that the indications for its use should be well established.

Chemical neurolysis may be appropriate for usein the following indications: • spasticity • paraplegia • as a peripheral nerve injection for painful neuralgias • as a visceral nerve block of the splanchnic nerves

or celiac plexus • sympatbolysis of the cervical, thoracic or lumbar

sympathetic trunks • motor pointinjections of striated muscles • injections of specific joints and their nerve supply.

In each case, pain must be localised and unilateral, dermatomal or have originated from damage to a single nerve. Sympathetically maintained pain is the most common indication for chemical neurolysis, with . very reliable results.

The most commonly used chemical neurolytic agents are phenol 6-16%, alcohol 95-100% and glycerol.

Alternative procedures for the management of nonmalignant pain are cryotherapy or radiofrequency, the latter being more discrete than chemical neuro­lysis or cryotherapy, and producing more complete nerve destruction than chemical neurolysis.

Study supports use in nonmalignant pain In Dr Abadir's study, epidural phenol 6% 5-20ml

in normal saline was administered after contrast

O'56-27031961103~'3/$O"OOo Adls International Umltecl 1996. All rights reserved

medium injection and fluoroscopy to patients with chronic, intractable pain of nonmalignant origin. 17 patients were treated on an outpatient basis with repeat injections after 12-24 hours as required.

1\'10 patients had sciatica (but were not candidates for surgery), 2 had failed back syndrome secondary to 2 or more laminectomies, 3 had thoracic compression fractures, 1 had diffuse facet arthropathy with bilateral rib cage pain, 6 had postherpetic neuralgia and 3 had lumbar compression fractures.

All patients experienced excellent pain relief and none developed motor or sensory deficits, loss of urine or bowel continence or any other adverse effects. The duration of the block ranged from 3 months to 1 year. Dr Abadir and colleagues emphasised that a local anaesthetic prognostic block should be administered prior to administration of the neurolytic block to determine patient suitability for the procedure.

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Inphanna- 4 May 1996 No. 1035

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