Pain Flashcards
what are 3 phases pain perception
Activation of noiceptors
Dorsal horn spinal cord
Brain response
What are noiceptors
peripheral sensory neurons known as nociceptors alert us to potentially damaging stimuli at the skin by detecting extremes in temperature and pressure and injury-related chemicals, and transducing these stimuli into long-ranging electrical signals that are relayed to higher brain centers.
What’s the dorsal horn do?
Recieves sensory information that enters the spinal
Cord via the dorsal routes and responds to noxious stimuli
SAME DAVE
Sensory = afferent
Motor = efferent
Dorsal = afferent
Ventral = efferent
What are prostaglandins a group of?
Where are they made ?
What processes do they control?
The prostaglandins are a group of lipids made at sites of tissue damage or infection that are involved in dealing with injury and illness. They control processes such as inflammation, blood flow, the formation of blood clots and the induction of labour.
How are prostaglandins synthesised
The pathway for making prostaglandins is an extension of the fatty acid synthesis pathway (Figure 6.10. 1). Prostaglandins, molecules associated with localized pain, are synthesized in cells from arachidonic acid (see previous page) which has been cleaved from membrane lipids
What are the pain descriptors for noiceptive pain
What are the excitatory chemicals associated with pain?
What are the inhibitory chemicals associated with pain?
Describe 3 ways in which analgesics can work?
- Decrease excitability receptors
- Decrease the transmission of pain signals in the peripheral nervous system
- block transmission of pain signals centrally
What are 7 properties of an ideal analgesic?
Easy to titrate to effective uses
Cost effective
No side effects
Reaches target quickly
Does not accumulate on repeated doses
Available in different formulations
Treats all types of pain
Step one of analgesic ladder
Mild pain paracetamol
+|or NSAID
Step 2 of analgesic ladder
Mild/moderate pain - weak opioid codiene +- nsaid
Step
3 of analgesic ladder
Moderate /severe pain strong opioid +- nsaid
5 examples of adjuvant meds
Biphosphonates - bone pain
Anticonvulsants -
Corticosteroids
Antispasmodic
Hot cold
Compress
Analgesic ceiling
Dose beyond which there is no additional effect
What is the MOA of paracetamol
Inhibits the cox enzyme in the CNS. This inhibits prostaglandin synthesis in the CNS. This reduces the pain
What does the cox enzyme
Do?
What does prostaglandin do?
What is the MOA of NSAIDs
NSAIDs inhibit the enzyme cycloxynase (cox2). Which block the production of prostaglandins
Why does the mode of action of NSAIDS cause GI disturbance
Name the 3 categories of opioids
- Pure full agonist - my
- Partial agonist /mixed agonist - kappa
- Pure antagonist - delta
What are the 2 classes of opioids
- Weak
- Strong
List 6 of the main side effects of opioids
Postural Hypotension
Sedation
Euphoria
Nausea and vomiting
Constipation
Respiratory depression
Define tolerance
Define dependency
How do opioids act on the opioid receptor?
As an agonist
What do opioids copy
The action of exogenous opioid
Such as endorphins
What is the mechanism of
Action of opioids
What’s nociplastic pain
symptoms observed in nociplastic pain include multifocal pain that is more widespread or intense, or both, than would be expected given the amount of identifiable tissue or nerve damage, as well as other CNS-derived symptoms, such as fatigue, sleep, memory, and mood problems. This type of pain can occur in isolation, as often occurs in conditions such as fibromyalgia
