Prehospital Analgesia

Dr David Teubner 20/7/5http://www.davidteubner.com/work_talks.htm

What is pain?

Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.

IASP 1986

Types of pain

• Lots of different calssifications• Acute vs chronic

Acute pain

• Cause is known• Temporary (< 6 weeks)• Located in area of trauma• Resolves spontaneously

Chronic pain

• Untreated pain may lead to neuronal changes which alter pain sensation and lead to chronic pain

History of prehospital analgesia

• US army ambulances in the 1860’s carried brandy for pain relief

• Even today there is very little scientific evidence for any of the techniques used

Analgesia myths

• No diagnosis = no analgesia• Analgesia masks clinical signs• We do a good job in providing analgesia• Any dose of morphine will provide pain

relief• Analgesia causes dependence• Analgesia causes adverse events

Time to analgesia

• Oligoanalgesia well recognised in EDs• Frequent source of patient complaint

Assessment of pain

• Pain is unique to the individual, it is influenced by• Age• Race• Gender• Culture• Emotional/cognitive state• Prior experience

Measurement of pain

• Visual analogue scales• Numerical rating scale• Verbal or adjective rating scale

(VRS/ARS): none, mild, moderate, severe, or unbearable.

Management of pain

• Non pharmacological• Drugs

– Methoxyflurane– Morphine

Non–pharmacological management

• Management of the underlying condition– Splinting fractures– Positioning

• Reassurance• Others

– Cognitive (guided imagery, music, distraction)– Behavioural (relaxation, breathing,

biofeedback)

Morphine history• Naturally derived from the opium poppy –

Papaver somniferum• Opium first used in about 4000 BC• First medical use in 200 BC• In the 16th century Paracelcus called it

laudanum (from latin laudare – to praise)• First isolated in 1803 by Serturner who called it

morphia.• Now called morphine instead as most plant alkaloids

end in “-ine”

Morphine• Narcotic Opiod analgesic• Bind to Opiod receptors to cause analgesia,

euphoria, sedation, and respiratory/physical depression

• Stimulates emetic chemoreceptors.• Peripheral vasodilitation and inhibition of

baroreceptors.• Histamine release is common• 2-20 mg IV

Paeds 0.1-0.2 mg/kg

Morphine indications

• Pain– Musculoskeletal– Chest– Abdominal

Contraindications

Known allergy

Morphine - precautions

• Prepare to manage hypotension and respiratory depression-use w/ caution in COPD and Asthma

• Inhibits peristalsis• Rapid injection increases incidence of

adverse reactions• Headache

Questions?