Pain Flashcards
What is Pain?
- A safety mechanism
- Can be acute, chronic or acute on chronic
- Subjective
- Often complex and multidemensional
What are the 3 Skin Receptor Types
- Mechanical (including pressure)
- Thermal
- Chemical
What do these Skin Receptors do?
- Some receptors respond primarily to one type of stimulation, while other receptors can detect all types.
- When tissue is injured, chemicals produced by the body (such as histamine or bradykinin) can excite pain receptors
- Prostaglandins that are released when inflammation occurs can sensitise nociceptors
What are 3 Types of Nerve Fibres? And what Information do they Carry?
- A (Myelinated) - carry information about touch
- B (Myelinated) - carry information about pain/temperature
- C (Unmyelinated) - carry information about pain/itch/temperature
What do a-delta Fibres do?
- 1st pain associated with sharp localised pain
- Stimulates protective withdrawal
- Signals go straight to cognitive area of the brain enable us to localise
- Not affected by opioids
What do a-beta Fibres do?
- Not directly involved in pain response
- Fastest of 3 fibres
- If stimulated enough can ‘overtake’ pain fibres and reduce the amount of pain sensations transmitted to CNS
- Sensitive to touch and sensation
What do C Fibres do?
- 2nd pain with a dull ache over broad area
- Terminate in wide areas of brain stem therefore pain is not localised; lingering pain a-delta fibres
- Responds well to opioids
How should a Pain Assessment be done? And why?
- Should be individualised, objective as pain for them not us
- Must have baseline see if pain has gone up/down
What are the Barriers to Effective Pain Management?
- Opioid addict
- Overdosed already
- Scared of getting addicted
- Belief - do we actually believe they’re in pain?
- Allergies
- Side effect reluctance
- Stoicism
- Age
- Non-verbal/communication barriers
- Equipment issues
Examples of Non-Pharmacological Management (5)
- Reassurance/Empathy
- Positioning eg splint
- Distraction
- Hot/Cold compression
- Breathing/relaxing
Pharmacological Management and Example of Drug in Each (6)
- Non-opioid (paracetamol)
- Inhalation (gas)
- Sedatives
- Weak opioids (codeine)
- Strong opioids (morphine)
- Other stuff (ketamine)
What is the Analgesic Ladder?
Increasing amount of pain relief, similar to stepwise management but for pain.
1. Non-opioids - ibuprofen, paracetamol, aspirin
2. 2. Weak opioids - tramadol, low dose morphine, codeine
3. 3. Strong opioids - morphine, fentanyl, oxycodone.
4. (4) Adjuvants - antidepressants, corticosteroid, anticonvulsant, muscle relaxant, antispasmodic
Gate Control Theory
- CNS has ability to** control input** of pain w/ use of ‘gate’ at spinal cord
- Impulses from a-delta and C fibres allow pain impulses ot go to brain
- Impulses from a-beta fibres close gate passing up to brain
- Theory is that impulses are stopped by closing the gate by stimulating the release of inability NT’s & neuro-modulates in synapses
Gate Theory Science/Modulation
- Pain inducing chemicals & NT’s are produced/stimulated at the periphery, the dorsal horn and within the brain
- However, this can be ‘modulated’ by the body’s own endogenous analgesics and ‘good’ NT’s, and by counter stimulus of** A-beta** fibres
- Analgesics can block ‘bad’ chemicals/receptors or mimic/prolong/stimulate the action of the ‘good’ ones
What does Enkephalin do?
- They’re a subgroup of endorphins so have a similar response as endorphins
- Distraction can reduce pain: a rationale for this is that activity in the Cerebrum influences descending nerve pathways, releasing endorphins and enkephalins.
- Distractions may be auditory or visual
