Flashcards in 230 Pain Deck (38):
What is the definition of chronic pain?
Pain which persists longer than normal healing times
What are the 4 components of the IMMPACT guidelines for chronic pain?
1. Pain intensity
2. Physical function
3. Emotional function
4. Participant rating of improvement
Which hereditary condition is due to mutations in the voltage gates Na channels?
Congenital insensitivity to pain
What is the TRPV-1 receptor?
Capsaicin receptor which is activated with heat or cold
Pain when >43 degrees
What are A-delta fibres?
Myelinated nociceptors - quick, unimodal
What are C-fibres?
What are A-beta fibres?
Nerves which detect pressure and tactile sensation - can inhibit nociception
Name 3 endogenous opioids
Through which part of the spinal cord do 1st order spinothalamic neurones ascend 1-2 levels in the spinal cord before decussating?
Where in the grey matter do 1st order neurones synapse with 2nd order neurones in the spinothalamic tract?
Name 3 parts of the brainstem which receive fibres from the spinothalamic tract
What do the descending tracts from the brainstem stimulate spinal interneurones to release in the feedback system?
What 2 things do the enkephalins released from the spinal interneurones cause to 'dampen down' pain APs?
1. Inhibits NT release from the presynaptic neurone
2. Hyperpolarises the post-synaptic membrane
Which opioid receptors do endorphins have the highest affinity for?
Which opioid receptors do enkephalins have the highest affinity for?
Which opioid receptors do dynorphins have the highest affinity for?
Which inflammatory factors activate/sensitise nociceptors during inflammation?
What is the action of substance P in nociception?
Stimulates release of histamine
Dilates blood vessels
What is primary hyperalgesia?
Increased pain sensitivity immediately following tissue injury
What is the treatment for trigeminal neuralgia?
Which NSAID has the lowest thrombotic risk?
Name 2 weak opioids
What is the treatment for opioid O/D?
Name 3 strong opioids
Which strong opioid is strongest against kappa and delta opioid receptors?
Name 2 common opioid S/E
What is the MOA of ketamine?
NMDA receptor antagonist
What is the intensive theory of pain?
Pain = emotional state caused by intense stimuli
What is Descartes theory of pain?
Single wire theory - pain has its own apparatus independent of other senses
What is the gate theory of pain?
Pain is not just related to extent of tissue damage - can have things which 'open' and 'close' pain gate.
Name 2 things which open the 'pain gate'
Anxiety and panic
Fear of pain
Name 2 things which close the 'pain gate'
Happiness and laughter
Relaxation and calm
What is dolorimetry?
Measuring pain threshold
What is the MOA of tramadol?
Inhibits reuptake of NA
Stimulates serotonin release
What are celecoxib and etoricoxib?
What is the precursor for COX enzymes?
What does COX 1 stimulate?
Thromboxane A2 for platelet aggregation
PGs in upper GIT - gastroprotective
PGs in kidneys - renal perfusion