pain control Flashcards
pain is a normal response to —-
-Encourages —
-Can become —
-Can become —
definition:
—-an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage
- injury
- rest
- pathological
- chronic
- pain
types of pain:
—- pain that arises from actual or threatened damage to non-neural tissue and is due to the activation of nociceptors
—- pain caused by a lesion or disease of the somatosensory nervous system (nerves that provide information about the body).
e.g. stroke, vasculitis, diabetes mellitus, genetic abnormality
—- pain that arises from altered nociception despite no clear evidence of actual or threatened tissue damage causing the activation of peripheral nociceptors or evidence for disease or lesion of the somatosensory system causing the pain
e.g. fibromyalgia, non-specific low back pain
—- Both nociceptive and neuropathic eg cancer pain
- nociceptive pain
- neuropathic pain
- nociplastic pain
- mixed pain
aspects of pain:
1- —- :
-The neural process of encoding noxious stimuli
-Nociceptors are high-threshold sensory receptors of the peripheral somatosensory nervous system that are capable of transducing and encoding noxious stimuli.
2- — :
Pain in response to an innocuous stimulus ( basically it causes u pain even when its not supposed to)
Pain in dressing
Common in neuropathic pain
3- exaggerated response to noxious stimulus
nociception
allodynia
hyperalgesia
pain duration:
1- acute pain:
— response to injury and takes — which prevents further injury
2- subacute pain:
- is due to —
- triggers —
3- chronic:
- — pain— injury
- non involved in repair
- pathological
immediate
sec
acute inflammation takes hours
repair
prolonged
post
notiception has 3 domains which are:
1- biological/physical : due to genetics sex age sleep magnitude of disease or injury , decondintioning loss of grey matter , etc ( leads to pain)
2- psychological : depression anxiety coping skills personality , poor concentration , etc( leads to suffering )
3- socioculture: job satisfaction social support system language and cultural barrier , isolation
description of pain:
- biring stabbing electric shock like is —>
- tenderness ashiness and stiffness —>
- descprtiion of nerve pain
description of muscle pain
stages of pain:
1- activation of — as:
2- transmission of pain to — which is inhibited by — and —
3- transmission of pain to —
- pain receptors ( nociceptors ) as bradykinin histamines and sensisted by prostaglandins
- spinal cord
- inhibited by enkephalin and endorphin
- brain
pain fibers:
1- alpha omega ( check slide for name)
- — — fibers
- speed conduction of —
- triggers – withdrawal reflex
- produces ——- pain
- allows – of pain
2- c fibers
- – fibers
- speed of conduction is
- produce —– pain aka — pain
- thinly militated
- 5-35 m/s
- immediate
- sharp localised immediate pain
- localisation
- slower unmylinated
- 0.5-2 m/s
- dull diffuse pain
-2ndary pai
treatment of pain:
Analgesics are used to mask pain
They do not treat the underlying problem
They can lead to further injuries
Can be important to help in recovery
Target specific pain pathway involved
( check slide 15,16)
opioid analgesics:
1- —Compounds related to substances found in the opium poppy, e.g. —
2- —- Natural or synthetic compounds that cause opiate-like effects
opiate
morphine
opioid
—- is an enzyme that breaks down enkephalins
- thiorphan :
1- active metabolite of —
2- used as —
3- inhibits —
- Research on developing enkephalinase inhibitors for —-
- ennkephalinase
- racecadotril
anti-dirraheal - enkephalinase
- pain control
opioid receptors :
- 5 types of opioid receptors:
m (MOP)
k (KOP)
d (DOP)
nociceptin/orphanin FQ (N/OFQ) (NOP)
Opioid growth factor receptor
- they are —
- promotes opening of —
- reduces —-
- inhibits opening of —- channels
- reduces —–
- g protein (Gai-linked)
-k+ channels
-neural excitability - voltage gated ca2+ channels
- neurotransmitters
morphine:
- m, k and d receptor –
- Marked elevation in pain threshold without loss of — (m and k receptors)
- euphoria for – receptors :): pleasant, ‘floating’ sensation with freedom from anxiety [dysphoria in some subjects (k receptors)]
- given —
- variable —
- modest t1/2 = —
- sustained release oral preparation to— duration of action
- patient controled by —
- agonist
- consiocusiness
- u receptors
- orally s.c i.m i.v
- 1st pass metabolism
- 3-4 hours
- increase
- i.v analgesia
morphine side effects;
Sedation, mental clouding/drowsiness
Respiratory depression: inhibits brain stem regulatory centre
Nausea, vomiting
Constipation: increased GIT muscle tone, decreased propulsive movements, reduced sensory stimuli for defecation reflex
Miosis: important in diagnosis of overdose
Tolerance and dependence
- other opioid angonsit :
1- pethidine ( or meperidine) : - efficacy is — morphine
- — > – agnosts
- — acting often used in —
- less liable to cause —
2- codeine : - – efficacy of u > k agonist
- 10% converted to —
- alleviation of — pain
- 3- fentanyl:
- 100+x —- potent than morphine
- used for – pain
4- oxydocodone
5- tramadol : - inhibits — and — uptake
- usually prescribed w —
less or equal
u > k agonist
short acting used in labour
constipation
low
morphine
mild moderate pain
antitussive ( cough suppressant )
more
cancer pain
inhibits serotonin
noradrenaline reuptake
paracetamol