12.10.08 Teaching

Pain ladder

• • Non-opioids

    • Paracetamol

    • NSAIDs

  • Weak opioids

    • Codeine

      • 30-60mg QDS

        • NB there is only 8-10mg in OTC co-codamol

      • Metabolised => Morphine

      • Approx. 1/8 - 1/10 the strength of morphine

      • Side effects: Constipation, N+V, Drowsiness/confusion

      • Doesn't work on 10% of people (can't metabolise to morphine)

    • Dihydrocodeine

    • Tamadol is half-way to step 3

  • Strong opioids

    • Morphine

    • Diamorphine

    • Oxycodone

    • Fentanyl

    • Buprenorphine

    • Hydromorphone

    • Methadone

    • (Pethidine)

Morphine dosing

• • Starting dose

    • 5mg a good choice

      • 10mg if young, fit

      • 2.5mg if old + frail

    • Give every 4 hours

    • Use oral verisons

      • Oramorph (liquid)

      • Sevredol (pills)

  • Breakthrough dose (PRN)

    • 1/6 total daily dose (i.e. same as each regular dose)

    • Prescribe 1 hourly

    • Max. 2 doses every 4 hrs

    • Max. 6 doses every 24 hrs

  • Recalculation

    • Add regular + breakthrough doses for the last 24 hrs

    • Make this the new daily regular total

      • i.e. Prescribe 1/6 of this every 4 hrs for the future

  • Conversion

    • Switch to slow-release morphine sulphate tablets

    • Divide total daily dose by 2 and give every 12 hrs as MST

    • Back-calculate to prescribe the PRN breakthrough dose

      • 1/6 the daily total

  • If NBM

    • Switch to subcut

    • Use continuous infusion

    • Twice as strong as oral, so divide total daily dose by 2

Morphine fears

• • Tolerance exists, but is linear and not exponential

    • => Doesn't ever stop working

  • Doesn't get you high if taken for pain

    • => No psychological dependance

  • Can safely ween off

    • But don't stop suddenly!

  • N+V

    • Yup, but only in 30%

  • Cognitive impairment / "out of it"

    • Only if the dose is too high

  • Mortality

    • Regular opioids do NOT decrease life expectancy

  • Constipation

    • Yes, in ~100%

Pain

• • Physical

    • Allodynia, hyperpathia, hyperaesthesia

    • A-delta + C fibres

  • Psychological

    • e.g. Running vs chemi

  • Social

    • Expectations

  • Spiritual

Respiratory secretions

• • Increase in last 24hrs

  • Important to get on top of it quickly, as reversal is hard

  • Use anti-cholinergics to fix

    • • Hyoscine butylbromide

      • Glycopyrronium

  • Buscopan

Terminal agitation

• • More common if:

    • Biochemical derangement

    • Young

    • Pre-existing cognitive impairment

  • Treatment (pref. IV/IM)

    • Haloperidol

    • Midazolam

Brief pain inventory

4 Signs of Imminent Death

Notes

• • Chlorpromazine

    • Typical antipsychotic

    • Dopamine antagonist

    • Additional antiadrenergic, antiserotonergic, anticholinergic and antihistaminergic properties

  • O + Q signs of impending death

  • NSAID side-effects

    • GI

    • Bronchospasm

    • Fluid accumulation

    • Nephrotoxic

    • Headache

  • Give pain relief:

    • By mouth

    • By the clock

      • i.e. NOT just in response to pain!

    • By the ladder

  • Interpretation of pain

    • e.g. After a marathon VS after chemo