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