Interventional Procedures in Chronic

Pain

Dr Brendan MoorePain Medicine Specialist PhysicianAdjunct Associate Professor

University of Queensland

Degenerative Lumbar Back Pain

Degeneration of Lumbar Spine

• Disc degeneration + narrowing

• Osteoporosis

• Facet Joint Arthritis

• Spinal and Foraminal stenosis

• Loss of Lumbar concavity

Posterior Elements

• Facet Joints frequently implicated in pain• Mechanical back pain with upper leg and buttock

radiation

Origins of lumbar pain

• Degenerative Discs

• Vertebral fractures

• Spinal / Foraminal Stenosis

• Disc Bulge / Prolapse

• Facet Joint

• Muscle / Soft tissue

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Invasive Treatment Options

• Surgery

• Facet Joint Injection

• Radiofrequency medial branch ablation

• Epidural / Caudal steroid

• Vertebroplasty

• Coeliac / Lumbar Sympathetic Plexus Blocks

• Sacro-iliac Joint injection

Appropriate conditions for interventional pain procedures

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• Aseptic conditions

• Monitored sedation with anaesthetist in attendance

• Image intensifying X-ray or CT guidance

• Appropriate analgesia

Procedures available at a pain clinic

• Epidural injections

• Facet joint injections

• Sacroiliac joint injections

• Medial branch blocks

• Radiofrequency nerve ablation

Epidural injections

• Most effective in the presence of nerve root compression and spinal stenosis

• Increased efficacy if given in the first weeks of the onset of pain

• Effects of the injection tend to be temporary (1 week to 1 year)

• Can be beneficial in providing relief for patients during an episode of severe back pain

• Allows patients to progress in their rehabilitation

Lumbar epidural injection

• 18G or 16G Toohey needle

• Radio-opaque contrast to confirm position

• Injection and distribution of local anaesthetic and steroid to nerve root

Lumbar Epidural Injection

Caudal Epidural Injection

Facet joint injections

• Back pain originating from facet joints

• Low back pain (unilateral or bilateral) and no root tension signs or neurological deficits

• Pain usually being aggravated by extension of the spine

• Facet joint injection may reduce inflammation and provide pain relief

• Therapeutic goal and potential benefit– Temporary relief from pain

– Patient may proceed into an appropriate exercise program

Facet Joint Injection

• Primarily diagnostic

• 25G Spinal needle

• LA + Steroid

• Steroid confers possible longer term benefit

Sacroiliac joint injection

• Indicated with referred pain

• Pain referral pattern – area around and just caudal to the posterior superior iliac spine

• Referred pain in the low back, buttocks, abdomen, groin or legs

• In some patients, S-1 joint injections can provide significant pain relief

Sacroiliac joint injection

• Diagnostic

• 25G spinal needle

• Local anaesthetic + steroid

• Steroid indicative of possible long-term benefit

Sacro-iliac Joint Injection

Medial branch blocks

• Medial branch nerves are the very small nerve branches that controls sensation of the facet joint

• Indicated in low back pain (unilateral or bilateral)

• Pain usually aggravated by extension of the spine

• Medial branch blocks are a diagnostic procedure

• Can provide temporary pain relief

Medial branch nerve ablation

• Diagnostic medial branch blocks

• Local anaesthetic + steroid

• Progress to radiofrequency ablation if diagnostic block indicative of long-term benefit

Medial Branch Nerve Ablation

• Denervation of Medial Branch via Radiofrequency Neurotomy

Radiofrequency neurotomy

X-ray to confirm needle position – AP and oblique views

Test stimulation – 2.0 Hz 0–2 volt to test for motor nerve contact

Lesion 85°C for 90 seconds

Cervical radiofrequency neurotomy

Position for C2/3 and C3/4 facet joint radiofrequency

Cervical Radiofrequency Neurotomy

Cervical radiofrequency neurotomy –lateral view

Marker shows needle at C2/3 facet joint

Coeliac Plexus Block

Facet joint injection

• Diagnostic

• 25G spinal needle

• Local anaesthetic + steroid

• Steroid indicative of possible long-term benefit

Prescribing opioids for chronic pain

Useful rules for prescribers

1. Opioid therapy – part of a wider pain management approach1

1. Therapeutic Guidelines, 2007. 2. Graziotti & Goucke, 1997.

2. Avoid using opioids in isolation1

3. Inform patients about the limits of opioid therapy2

4. Arrange for a trial of opioid with clear review point2

5. Regular prescription requires regular review2

6. One doctor responsible for prescribing opioids2

7. Refer to another GP or pain specialist if concerned about prescription or if opioid therapy is not achieving desirable results2

4–6 week sustained release opioid trial

• Informed consent

• Treatment contract1

• Single prescribing doctor1

• Low dose sustained release

Review at one week

• If tolerating dose, increase gradually1

• Schedule regular follow up (e.g. every 10–14 days) if needed2

If not tolerating opioid trial

• EXIT CRITERIA1

1. Therapeutic Guidelines Ltd, 2007. 2. Graziotti & Goucke, 1997.

Review of opioid trial

• Discuss progress and outcomes

• Functional goals achieved?• Medication used responsibly?

• Discuss risks / benefits of continued therapy

• Assess 4 ‘A’s1

– Analgesia– Activity – Adverse effects – Aberrant drug behaviours

1. Gourlay & Heit, 2005.

Opioid prescribing: dose limits and considerations

Suggested maximum opioid dose

• Consult a Pain Medicine Specialist if higher doses considered necessary

1. Hunter Integrated Pain Service. Opioid use in persistent pain. November 2010

Drug Maximum dose for GP prescription

Morphine 120mg daily

Oxycodone 80mg daily

Hydromorphone 24 mg daily

Methadone 40mg daily

Fentanyl transdermal patch 25 mcg/hr applied every 3 days

Buprenorphine transdermal patch 40 mcg/hr applied weekly

Tramadol 400 mg daily

Dose conversion

Morphine equivalence to

Ratio morphine : named opioid

Examples of equivalent doses

Codeine 1:6 Morphine 10 mg Codeine 60 mg

Oxycodone 1.5:1 Morphine 60 mg Oxycodone 40 mg

Hydromorphone 5:1 Morphine 60 mg Hydromorphone 12 mg

Tramadol 1:5 Morphine 10 mg Tramadol 50 mg

Fentanyl Morphine 90 mg Fentanyl 25 mcg/h

Buprenorphine 75:1 Morphine 9 mg Buprenorphine 5 mcg/h

Methadone 3:1 Morphine 60 mg Methadone 20 mg

1. Hunter Integrated Pain Service. Opioid use in persistent pain. November 2010

Opioid trial guidelines

• Commence trial with low dose sustained-release opioid

Use a lower dose and titrate slowly in patients who are:

• Elderly

• Taking other CNS depressants

• Opioid naïve

• Have severe hepatic or renal dysfunction

1. Graziotti & Goucke, 1997.

Federal requirements

PBS prescription

Restricted benefit

• Chronic severe disabling pain not responding to non-narcotic analgesics (treatment <12 months)

• If treatment required beyond 12 months, patient must be reviewed by a second medical practitioner

• Authority required when prescribing increased quantities of opioid and/or repeats

– By phone – 1 month’s supply with no repeats

– In writing – 1 month’s supply with 2 repeats

• Short term supply can be prescribed without an authority

Department of Health and Ageing, 2008.

State requirements - QLD

• If intend to prescribe S8 drugs for longer than 8 weeks, forward a “Report to the Chief Executive” through the Drugs of Dependence Unit (DDU)

• A treatment approval from the Chief Executive is required prior to treating, for any controlled drug for a patient considered to be drug dependent

• For approvals and “Reports to the Chief Executive” contact the Drugs of Dependence Unit

– Phone 3328 9890

– Fax 3328 9821

Preventing doctor-shopping

Medicare Australia

Prescription Shopping Information Service

• If patient suspected of getting medicine in excess of medical need, contact the Prescription Shopping Information Service:– Complete and sign the registration form available at

www.medicareaustralia.gov.au

• Registration confirmed within 2 business days (fax) or by mail

– Information Service available 24/7 for registered GPs to:

• Find out if patient has been identified under the Prescription Shopping Program

• Receive information on the amount and type of PBS medicine recently supplied to that patient

1800 631 181

Summary – opioid pathway

Multidimensional assessment GP +/– practice nurse +/– others

Opioid trial

Maintenance therapy

Authority to Prescribe

Review

Exit from pathway:

i. Goals of therapy not achieved in trial or maintenance phase

ii. Predominance of psychosocial issues

iii. Evidence of aberrant drug related behaviour

Integrated Pain Service, 2008.

Is the patient suitable for opioid therapy?