Neuropathic Pain 25.9.07

Neuropathic Pain.

Dr. Christopher A. JennerConsultant in Pain Medicine and Anaesthesia, SMH

25th September 2007

Agenda

• Definition

• Physiology

• Acute

• Chronic

• Neuropathic

• Differences

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Definitions

• Pain. ‘An unpleasant sensory and emotional experience which we primarily associate with tissue damage or describe in terms of tissue damage, or both.’ (IASP 2001)

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Definitions (2)

• Time-course:

• acute

• chronic

• Type:

• nociceptive

• neuropathic www.londonpainconsultants.com

Pain Physiology

(boring)

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Pain Physiology

(funky version)

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Prevalence

• Acute pain • SMH 13,213 operations p.a. (Nov 03-04, DSU 41%)

• SMH 484 operations p.m. (Sep 04, Main, 15% PCA/ epi)

• Chronic pain • 7-14% UK population • ‘1 in 7’ figure

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The Challenges of Acute Pain

• Primary Care

• ↑ healthcare utilisation

• Secondary Care

• ↑ length stay/ complications • 10-15% post-op chronic pain (Macrae)

Acute Pain Management

• Non-pharmacological • RICE

• Pharmacological • WHO ladder (amended from cancer)

Step 1 paracetamol/ NSAID/ COX 2

Step 2 + weak opioids

Step 3 + strong opioids

The Challenges of Chronic Pain

• Bio-psycho-social model

• Individual and societal costs

• Biological- pain/ suffering/ disability

• Psychological- anxiety/ depression

• Social- work/ relationship/ family/ benefits

Massive Financial Burden

• NHS/ DWP/ tax-payers

• Lower back pain (CSAG 1994)

• NHS £481 million

• The Exchequer £1.4 billion

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Physical and Alternative Treatments

Physical and Alternative Treatments

• Physical- heat/ cold/ TENS/ hydro/ supports/ US/ IR

• Manipulation- PxTx/ chiropracter/ osteopathy/ deep tissue massage

• Alternative- acupuncture

Any Vets in the audience?

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5. (a) Veterinary practitioners?

Headache!

Pharmacological Treatment

Pharmacological Treatment

• WHO analgesic ladder (abridged)

• + tramadol • + opioids- buprenorphine TDD/ oxycontin/ fentanyl TDD

• (New: sufentanyl TDD/ product X)

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Opioid Therapy

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Pharmacological treatment of Neuropathic Pain

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Neuropathic Pain Management

• Antidepressants- Amitryptilline

• Anticonvulsants- Gabapentin/ Pregabalin/ Carbamazepine/ Valproate

• Opioids• Local Anaesthetics- Lignocaine/ EMLA

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• NMDA antagonists

• Sympatholytics

• GABA -ergics

• Capsaicin

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Future Agents for Neuropathic Pain

• Ziconotide (sea snail, conus magnus)

• P2X3- (purine) receptor antagonists (ATP) (knockout mice)

• Epibatidine (Equadorian poison dart frog)

• Morphine and ketamine

• Regular gabapentin

• Dexmetomidine

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Psychologicaly based therapy

Pain Management

• Psychological

CBT

Operant Conditioning

Psychoanalysis

Relaxation

Biofeedback

• Psychiatricwww.londonpainconsultants.com

Pain Management Programmes (MDT)

● Medication

• Coping

• Contingency

• Pacing

• Education • Goals (SMART- specific/ measured/ agreed/ realistic/ timed)

• Pain Behaviours

• Reinforcementwww.londonpainconsultants.com

Minimally Invasive Pain Management

Chronic Pain Management

• Nerve block techniques: - Epidurals - Facets - Tenoperiostial - ON - SSN - Occipital N - Ilioinguinal

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Neuropathic Pain Management

• Non-pharmacological • Nerve blockade- lumbar

sympathectomy/ stellate/ guanethidine

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The Kit

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The Target

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C-arm

Radiofrequency

Epiduroscopy

IDET

Disc Dekompressor

Vertebroplasty

Exotica

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Nerve Stimulation

Nerve Stimulation (2)

Intrathecal Pumps

Intrathecal Pumps (2)

The Future?

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The Future?

• Demographics

• Healthcare advances

• ↑ Patient expectations and involvement

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Summary

• Very common (1 in 7 UK)

• Time course- acute n chronic

• Nociceptive and neuropathic

• Massive socio-economic impact

• Multiple treatment modalities

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Any Questions