Lecture 9: Pain Management & Analgesics

definition of pain

unpleasant sensory and emotional experience associated with actual or potential tissue damage

Cutaneous

skin/subcutaneous tissue

Somatic

muscles, bones and joints

Visceral

internal organs; poorly localised/referred pain

Neuropathic

caused by nerve damage/dysfunction

Nociceptive

Caused by tissue damage activating pain receptors

what is the pain pathway 4 stages

transduction, transmission, perception, modulation

Transduction

Noxious stimulus activates nociceptors

transmission

Pain signals travel to CNS via nerves

A delta fibres are

fast, sharp, sudden pain

C fibres are

slow, dull aching pain

Perception

Brain interprets pain (thalamus and cortex).

Modulation

Descending pathways release chemicals that reduce/inhibit pain signals.

what is the gate control theory

• pain signals pass through a gate in the spinal cord

• large fibres, close the gate, reduce pain

• small fibres, open the gate, increase pain

what reduces pain (gate control theory)

rubbing, massage and acupuncture, stimulate large fibres reducing pain

subjective data is

what the patient tells you about their pain

objective data is

what you observe

PQRST stands for?

• provocation

• quality

• region/radiation

• severity

• timing

Non-opioids/NSAIDs

paracetamol, aspirin

Weak/mixed opioids

codeine, tramadol

Strong opioids

morphine, fentanyl, oxycodone

Co-analgesics

antidepressants

Multimodal analgesia

Combining different pain-relief methods to improve pain control

NSAIDs action

Reduce prostaglandin production, reduce pain and inflammation.

three side effects of NSAIDs

gastric irritation, kidney damage, fluid retention

3 nursing considerations for NSAIDs

• monitor for GI bleeding

• Monitor renal function

• Use caution with warfarin and other anticoagulants

Paracetamol action

Inhibits prostaglandin synthesis in CNS; reduces pain and fever.

Paracetamol overdose antidote

Acetylcysteine

Tramadol action

• inhibits serotonin and noradrenaline reuptake

• reduces pain transmission

Tramadol routes

oral, IV, IM

Opioid analgesics - weak/moderate

Codeine, oxycodone

Mechanism of action - opioid

• bind to opioid receptors in the CNS

• Decrease pain transmission in the spinal cord

• alter emotional perception of pain

• Depress the respiratory centre

Nursing considerations – opioids - 4

1. Monitor vital signs

2. naloxone must be available

3. Monitor for sedation

4. don’t break slow-release tablets

Naloxone (Narcan)

blocks opioid receptors

Naloxone (Narcan)

reverses opioid overdose/respiratory depression

route for Naloxone

IV

Non-pharmacological pain relief - 4

• distraction, e.g., music

• massage

• heat/cold packs

• exercise

Postoperative pain management list 4

• assess pain regularly

• give analgesia before pain becomes severe

• discuss pain management before surgery

• use multi-model analgesia

the nursing process - pain management (APIE)

• assessment

• planning

• implantation

• evaluation