Pain/Fever Lecture Flashcards
What is somatic pain?
Skin, bone, joint, muscle, connective tissue
What is visceral pain?
Internal organs–> pancrease, large intestine
Define nociceptive pain
acute pain
Define neuropathic pain
chronic pain
What is the gate control theory of pain?
Brain acts as a gate to increase/decrease flow of nerve impulses from peripheral fibers to CNS
What is the neuromatrix theory?
Each person has a unique genetically built in network of neurons called self body neuromatrix
What happens when there is stimulation of nociceptors?
Releases: luekotriens, serotonin, histamine, PGs, substance P, bradikinins
Receptor activation is transmitted along afferent nerve fibers to the spinal chord
What are nociceptors?
Found in somatic and viceral structures
Activated & sensitized by mechanical, thermal and chemical impulses
Distinguish between noxious and inncuous stimuli
How is nociceptive pain transmitted?
Large diameter and sparsely myelinated A fibers evoke sharp and well localized pain
Small diameter unmyelinated C fibers produce dull aching and poorly localized pain
What do afferenct nociceptive pain fibers release?
Neurotransmitters: glutamate, substance P and calcitonin gene-related peptide
What does the thalamus do?
Works as a relay station for transmission
What is pain influenced by?
Interactions between neuroreceptors and neurotransmittors in the synapse
What is pain perception?
Conscious experience takes place in higher cortical region in the brain
Brain can only accommodate limited number of pain signals
Cognitive and behavioral functions can modify pain by decrease pain signals
Relaxation, distraction, mediation, help in reduction
What is modulation of pain?
Endogenous opiate system
Neurotransmitters: endorphins, dynorphins, enkephalins
Recepts: mu, delta, kappa
Endogenous opioids bind to receptors- modulate pain impulse
NMDA activation leads to?
Decrease binding of opiates to receptors
What occurs in chronicn pain?
Disengaged from noxious stimuli
Nerve damage
Burning, tingling, shooting pain
What is the location, nature, onset and duration of tension-type headaches?
Bilateral
Varies from diffuse ache to tight pressing constricting pain
Gradual
Minutes to days
What is the location, nature, onset and duration of migraine headache?
Usually unilateral
Throbbing
Sudden
Hours to 2 days
What is the location, nature, onset and duration of sinus headache?
Face, forehead, or periorbital area Pressure behind eyes or face > Dull, bilateral pain & worse in the morning Simultaneous with sinus symptoms Days
What is the vascular hypothesis of migraine headaches?
Intracerebral aterial vasoconstriction followed by extracranial vasodilation
What happens during a migraine headache?
Perivascular axons release calcitonin gene-related peptide, neurokinin A and substance P
Released peptides interact with dural blood vessels to promote vasodilation and neurogenic inflammation
Migraine headache’s neurotransmitter is what?
Serotonin (5-HT)
What is Devil’s Claw?
Inhibits lipoxygenase and COX-2
Helps in the production of TNF-alpha (anti-inflammatory)
- Lower back pain
50-100 mg harpagoside daily reduce low back pain
Cause hypoglycemic effects
What is feverfew?
Leaves used for prevention of migraine headaches - Reduce incidence of attacks Less nausea and vomiting Inhibits PG synthesis Increases risk of photsensitivity
What is comfrey?
Suppress degranulation of azurophil granules and superoxide generation in leucocytes
Reduces inflammation
Same effect as diclofenac in reducing pain and inflammation
Contains pyrrolizidine
What is bromelain?
May inhibit the synthesis of PGs
Activates plasmin produciton from plasminogen
Reduces pain and inflammation after tooth extraction
May reduce pain while walking after episiotomy
Increase absorption of antibiotics
Inhibit platelet aggregation-risk of bleeding
Lowers bradykinin and kininogen
What is a fever?
Rise in body temperature Normal = 37 Fever - 37.8 Thermoregulation in response to pyrogens Deregulation results in fever Infections frequently cause this
Define Hyperpyrexia
Temperature over 41.1 or 107
What is the pathophysiology of fevers?
Microbial infection
Noninfectious: cancer, tissue damage, surgery, etc
Drug induced: anti-infective, anti-neoplastics, cardiovascular, CNS agents
Pyrogens: Exogenous (microbes, toxins) or endogenous (TNF)
What are anti-infectives?
Isoniazid, sulfonamids
What are anti-neoplastics?
Chlorambucil
Daunorubicin
What are cardivascular?
Nifedipine
Procainamide
What are CNS agents?
Barbiturates
Lithium
How is the hypothalamus involved in fever pathophysiology?
Controls body temperature homeostasis by setting a target temp for the
Feedback: peripheral nerves sending cool/warm sensation to brain and tissue
Balances heat loss and production
How could you increase the set temp?
Exposure to pyrogens results in release of arachidonic acid metabolites
These metabolites cross BBB, and increase the temp
What do sympathetic signals cause?
Vasoconstriction and decreased heat loss through skin
What drugs are used for pain/fever management
Acetaminophen (inhibit COX3)
Aspirin (inhibits cyclooxygenase –> decreases PGs; inhibit COX1)
Ibuprofen (inhibits cyclooxygenase –> decreases PGs; inhibit COX1)
Other NSAIDs
