Basics of Pain Management

1. Basics of Pain Management Dr. Allistair Dodds Dept. Pain Medicine Sunderland Royal Hospital July. 07

2. 3 Types of Pain (temporal) • Acute • Chronic • Cancer

3. Types of Pain (physiological) • A fibres • C fibres • Sensitisation

4. WHO should take the place of Descartes?

5. WHO ladder • Cancer pain • Step 3: opioid for moderate to severe pain +/- non opioid +/- adjuvant • Step 2: opioid for mild to moderate pain +/- non opioid +/- adjuvant • Step 1: non opioid +/- adjuvant

6. The “5” phrases • By mouth • By the clock • By the ladder • For the individual • Attention to detail

7. The “5” phrases • By mouth • For the individual • Attention to detail

8. Science and Sociology • Drugs targeted at the lesion • Analgesia targeted to the patients requirements

9. Cyclo-oxygenase • COX converts arachidonic acid to prostaglandin H2 – a precursor of the inflammatory prostaglandins. • Type 1 - constitutive maintains the function of gut, kidneys, platelets etc. • Type 2 – inducible, expressed during the inflammatory response

10. Paracetamol • Simple analgesic • Anti-inflammatory - periphery • Anti-pyretic - hypothalamus

11. Pharmacology • Tablet, effervescent, syrup, suppository, iv infusion • NNT 3.8 (3.4-4.4) 50% pain relief acute pain‡ ‡Henry McQuay & Andrew Moore; An evidence based resource for pain relief; Oxford Medical Publications 1998

12. Non steroidal anti inflammatory drugs (NSAID’s) • Simple analgesic • Anti-inflammatory - periphery • Anti-pyretic – hypothalamus

13. Efficacy • All common NSAID’s have an NNT of : • 2.3 (2.0-2.7) for 50% acute pain relief‡ • No difference between the cox 2 specific (rofecoxib), selective (naproxen) and indiscriminate (ibuprofen) drugs. ‡Henry McQuay &Andrew Moore; An evidence based resource for pain relief; Oxford Medical Publications 1998

14. Side effects • Can be partially predicted by the interaction of NSAID’s and COX 1. • Gastric ulceration • Heart failure – deteriorates • Renal failure – deteriorates • Platelet dysfunction

15. Side effects newer drugs • Newer Cox 2 specific drugs cause less gastric and platelet effects but just as dangerous in renal and heart failure. • The reduction in dyspepsia sometimes improves compliance.

16. Opioids • Bind to mu (μ) receptors in spinal cord and brain inhibiting the transmission of electrical activity that signals pain. • Grouped according to potency (weak – strong)

17. Weak opiods • Codeine – pro-drug not metabolised to active agent (morphine) in 17-34% of patients. • Dihydrocodeine – pro-drug, again a wide variation in patient response. • Tramadol – active drug.

18. Efficacy • NNT’s • Tramadol 100mg 4.8 (3.8 - 6.1) • Dihydrocodeine 30mg 8.1 (4.1 – 540) • Codeine 60mg 16.7 (11- 48) • But… • paracetamol 1g + codeine 60mg = 2.2 (1.7 –2.9) Henry McQuay & Andrew Moore; An evidence based resource for pain relief; Oxford Medical Publications 1998

19. Strong opiods • No requirement for metabolism • 50% oral bioavailability • Fentanyl patch 25 - approx 90mg oral morphine per day

20. Morphine • Presentation • Tablets, capsules, solutions , patches, suppositories, iv injection. • Usually titrated to effect.

21. Side Effects • Common adverse reactions : constipation, nausea and vomiting, drowsiness, dizziness, headache, itch, dry mouth,. • Infrequent adverse reactions include: dose-related respiratory depression , confusion, hallucinations.

22. Chronic Pain • An alternative evidence based approach.

23. Pain Management Programme • Given the multi-dimensional nature of long-standing pain problems, the most effective approach is to treat through multi-professional teams. • PMP is a psychologically framed, group based rehabilitation treatment that utilises the biopsychosocial model as the philosophical underpinning to assist people in the further development of pain self-management.

24. Pain Management Programme • Programme Structure • PMP is a 12 session (x3.5 hrs) treatment delivered over a year: • 8 intensive sessions (weekly) • 4 consolidation sessions over next 10 months (1, 2, 4 and 6 months). • “Graduate programme”

25. The Treatment Components 1.Educational: eg. gate-control theory, active neuro-matrix. 2.Cognitive Restructuring: Skills to modify unhelpful pain and negative affective state related cognitions. 3.Problem Solving: Developing solutions to carry out desired goals. 4.Coping Skills Training: Behavioural management (baselines, pacing). 5.Relaxation: Assisting people gain increased control over heightened physiological arousal. 6.Exposure to Feared Activities: Reduction of avoidance and testing out activities to reverse de-conditioning.

26. Acessing the Service • Referal to the Pain clinic. • Intitail MDT assessment. • Those wishing to be considered for the PMP offered an education session about this treatment. • Patients then offered a short PMP assessment to determine their therapeutic goals. • Formal assessments are taken of key clinical parameters (defined from the biopsychosocial model) that are targeted for active change. • Following the successful completion of these procedures, patients enter the treatment (structured in a group based format).