Anaesthetics - Pain Flashcards
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”
Benefits of treating pain (for patient)?
- Physical
- Improved sleep, better appetite
- Fewer medical complications
- (e.g. heart attack, pneumonia)
- Psychological
- Reduced suffering
- Less depression, anxiety
Benefits of treating pain for the family?
- Improved functioning as a family member (e.g. as a father or mother)
- Able to keep working
- Socially this allows society to have lower health costs and contribute to society
What are the classifications of pain for: Duration, Cause and Mechanism?
Duration: Acute, Chronic, Acute on chronic
Cause: Cancer, non-cancer
Mechanism: Nociceptive (WHO pain ladder), neuropathic (need adjuncts)
[underlined is most useful]
Explain acute vs chronic.
Acute: Pain of recent onset and probable limited duration
Chronic: Pain lasting for more than 3 months, Pain lasting after normal healing, Often no identifiable cause.
Acute on chronic - an acute flare up of a chronic conditions
Explain cancer pain vs non-cancer pain.
- Cancer pain
- Progressive
- May be mixture of acute and chronic
- Non-cancer pain
- Many different causes
- Acute or chronic
Explain nociceptive pain.
- Obvious tissue injury or illness
- Also called physiological or inflammatory pain
- Protective function: if something hurts, we stop doing it etc
- Description
- Sharp ± dull
- Well localised
- Abdo visceral pain is slightly more difficult to localise
Explain neuropathic pain.
- Nervous system damage or abnormality
- Tissue injury may not be obvious
- Does not have a protective function
- Description
- Burning, shooting ± numbness, pins and needles
- Not well localised, all over kind of pain
What are the 4 steps of pain pathology?
- Periphery
- Spinal cord
- Brain
- Modulation
Patients pain response is driven by the cortex. If someone expects pain they are more likely to experience the pain.
Explain the peripheral step in pain pathology.
- Tissue injury
- Release of chemicals e.g. Prostaglandins, Substance P [these accentuate the pain pathway - amplify the signal]
- Stimulation of pain receptors (nociceptors)
- Signal travels in Aδ or C nerve to spinal cord
Explain the spinal cord step in pain pathology.
- Dorsal horn is the first relay station
- Aδ or C nerve synapses (connects) with secondary nerve
- Second nerve travels up opposite side of spinal cord
Explain the brain step in pain pathology.
- Thalamus is the second relay station: limbic for behavior, cortex for seeking help, brainstem for BP RR and other responses
- Connections to many parts of the brain
- Cortex
- Limbic system
- Brainstem
- Pain perception occurs in the cortex
Explain the modulation step in pain pathology.
- Descending pathway from brain to dorsal horn
- Usually decreases pain signal
- People who do more effectively have less pain
What is the gate theory of pain?
What are the features of neuropathic pain? Please include some examples.
- Abnormal processing of pain signal
- Nervous system damage or dysfunction
- Needs to be treated differently
- Examples
- Nerve trauma, diabetic pain (damage)
- Fibromyalgia, chronic tension headache (dysfunction)
What are pathological mechanisms that affect pain receptors in neuropathic pain?
Light touch of skin can cause a painful stimulus in these patients.
- Increased receptor numbers
- Abnormal sensitisation of nerves
- Peripheral
- Central
- Chemical changes in the dorsal horn: changes in neuromodulators
- Loss of normal inhibitory modulation
Give some examples of simple analgesics
- Paracetamol (underated hun xoxo)
- Non-steroidal anti-inflammatory drugs:
- diclofenac, iboprufen
- There is no antidote to these so be careful when administrating
- Can cause many issues such as kidney problems
- if you’re hingin take them both at the same time, rt to save a life
What is the WHO analgesic ladder?
