Peri-operative pain management from Anaesthetist, Dr Toni Hundle for The Arm Clinic at HCA The Wilmslow Hospital 2019

1. Pain
Dr Toni Hundle

4. What is it?
Biological

6. What is it?
Biological
Psychological

8. What is it?
Biological
Social
Psychological

9. Acute vs Chronic
• 3 months
• Biology changes quickly
• Presentation differs
• Management is also different

10. Acute Pain
• Nociceptor response from trauma, injury, surgery etc.
• Classic Inflammatory response –
• rubor (redness)
• tumor (swelling)
• calor (increased heat)
• dolor (pain)
• Treat with R.I.C.E, drugs, injections, slings and supports, psychology

12. WHO ladder
Paracetamol
NSAIDS
Weak
Opioids
Strong
Opioids

13. Paracetamol
• Acetaminophen, Tylenol, Panadol etc.
• 500mg UK, vs 375mg U.S.A
• 60-90% bioavailability orally and onset 35-40 minutes
• 8 minutes IV
• Metabolised in liver; excreted by kidneys, relatively safe in pregnancy
• Under 50kg – 500mg, QDS
• Over 50kg – 1gm, QDS
• Still kills a lot of people after deliberate or accidental overdose!

14. NSAIDs
•Salicylates – Aspirin
•Proprionic Acid – Ibuprofen, naproxen, ketoprofen
•Acetic Acid – Indomethacin, ketorolac, diclofenac
•Enolic Acid – Piroxicam, meloxicam, tenoxicam
•Selective COX2 inhibitors – Celecoxib, parecoxib

15. Phospholipid
Arachidonic
Acid
Prostaglandins
Cyclo-oxygenase 1 and 2
Phospholipase
Corticosteroids
NSAIDs
Vascular Cell Walls etc.

18. NSAIDs
• Balance risk vs benefit
• Controversy of COX specific inhibitors and cardiac risk
• Now seems to be an issue with all NSAIDs
• Use the lowest dose possible for least amount of time.
• Wean off first.
• Review after 2 weeks, especially in at risk groups.
• Stop immediately if any side-effects at all.
• Prefer Ibuprofen, 400mg TDS – protect stomach.

19. Opiates and Opioids - Morphine
• Morphine oral bioavailability is about 23%
• Peak levels after 45 minutes in liquid form
• Hepatic metabolism to an active metabolite
• 5-10mg (10mg in 5ml) oromorph, 4 hourly prn.
• S/E constipation, nausea, itching, urinary retention, sedation
• BUT, no organ toxicity, unlike NSAIDs

20. Opiates and Opioids - Codeine
• Codeine has more predictable oral bioavailability, 90%
• 15-30 minute onset
• Metabolised to morphine in liver
• Cytochrome P450 enzyme is gene sensitive. Some can and others
can’t metabolise. Variability in effectiveness.
• Used with paracetamol and NSAIDs
• S/E limit usage
• Max 60mg QDS daily

21. Opiates and Opioids - Tramadol
• Not a purely opioid mechanism
• Has 5HT (serotonin) and Noradrenaline actions
• 15-30 minute onset
• Metabolised to morphine in liver
• Cytochrome P450 enzyme is gene sensitive. Some can and others
can’t metabolise. Variability in effectiveness.
• Used with paracetamol and NSAIDs
• S/E limit usage
• Max 100mg QDS daily