PAIN Flashcards
What is pain?
pain is an unpleasant sensory and/or emotional experience. it is also the 5th vital sign, subjective
what are the 2 components of pain?
physical- sensation of pain
psychological- emotional response to pain sensation
what are the 2 classifications of pain?
acute- recent onset, transient, identifiable cause, protective mechanism
chronic- persistent or recurrent pain, the cause is complex/unclear
What is the first phases involved in nociception?
- Transduction- begins when nerve endings (nociceptors) of C fibres and A-delta fibres of primary afferent neurons respond to noxious stimuli. pain impulse is generated by an exchange of sodium and potassium ions (de-polarisation and repolarisation) at the cell membranes. results in an action potential and generation of a pain impulse.
what is a nociceptor?
A nociceptor is a sensory neuron that responds to damaging or potentially damaging stimuli by sending “possible threat” signals to the spinal cord and the brain.
in the transduction phase what chemicals are released?
Histamine, bradykinin, serotonin, substance P
what is a PCA? why?
patient-controlled analgesia, patients are able to have a dose of medication without calling the nurse and ask for it.
why? pt experiences better pain relief & maintain control
maintains steady serum level and avoids peaks and valleys of iv opioids given intermittently
what is a nerve block?
when a local anaesthetic is placed next to a nerve. blocks the transmission of neuronal messages along the nerve and so the area supplied by that nerve will feel numb for a temporary period
what is epidural analgesia?
is the delivery of analgesia in the epidural space. one of the most effective forms of pain relief.
somatic vs visceral??
somatic pain comes from the skin, muscles and soft tissue. aching, often constant, often worst w/ movement, well localised
visceral pain comes from the internal organs. poorly localised, constant cramping/ aching. eg, bowel obstruction
a-delta vs c-fibres
A-DELTA FIBRES= fast conducting, myelinated
well localised, sharp, stinging, pricking, fast or first pain (A COMES BEFORE C), high threshold receptors- respond to stimuli over a certain intensity
C-FIBRES= slow or second pain, unmyelinated, (C IS AFTER A), diffuse, burning, dull, aching
pain assessment- PQRSTU
PROVOCATION/ PALLIATIVE- what makes it worse/ better?
QUALITY/ QUANTITY
REGION/ RADIATION- where? one spot or radiates?
SEVERITY
TIMING- onset, how long it lasts
AFFECTING YOU
what is morphines mode of action?
full opioid agonist, binds to opiate receptors in the brain and spinal cord resulting in inhibition of the ascending pain pathways therefore altering the perception and response to pain.
what are some side effects of morphine?
respiratory depression, nausea and vomiting, drowsiness and constipation
what are the 4 phases of pain?
TRANSDUCTION- nerve endings (nociceptors) respond tp noxious stimuil, pain impulse is generated by action potential (changing noxious stimuli into a pain impulse)
TRANSMISSION- pain impulse is transmitted from the site of transduction, along the nociceptor fibres to the dorsal horn. pain impulse transmitted by substance P and then transmitted to the brain through ascending pathway.
PERCEPTION- pain is perceived, reticular system- autonomic and motor response to pain and for warning individuals to do something. somatosensory cortex- involved w/ perception and interpretation. limbic system- emotional and behavioural response
MODULATION- descending modulatory pain pathways, can lead to increase in pain impulses or decrease. descending inhibition= realease of inhibitory neurotransmitter that block/partially block the transmission of pain impulses and produce an analgesic effect.
