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Flashcards in Pain Physiology Deck (71):
1

what is pain

unpleasant sensory and emotional experience completely subjective and not proportional to the tissue damage

2

how does pain stimulation of the sympathetic nervous system affect the body

stimulates endocrine and metabolic systems and causes abnormalities
retards recovery from trauma, surgery, and disease

3

define acute pain

lasts less than 6 months
subsides once healing process is accomplished

4

define chronic pain

constant and prolonged over 6 months, involves altered anatomy and neural pathways, sometimes for life

5

why should you treat pain

tissue damage can cause disabling, refractory, chronic situations that pain prolongor outlast the period of healing

6

what is cousins theory of acute pain

severe unrelieved acute pain results in abnormally enhanced response that cause pronounced and increasing pathophysiology

7

what are some harmful effects of pain

increased adrenergic stimulation
increase heart rate, cardiac output, and myocardial oxygen consumption
decreased pulmonodayr vital capacity, alveolar ventilation, and functional residual capacity
arterial hypoxemia
suppression of immun functions

8

what are the pain receptors

free nerve endings

9

what are the two types of pain neurons

A delta- first pain, sharp (protective)
C- second pain, dull (learning)

10

what can stimulate these receptors

mechanical damage
extreme temp
chemical irritation

11

what are the four distinct processes in the pain pathway

transduction
transmission
modulation
perception

12

what is transduction

local biochemical changes in nerve endigns that generate a signal

13

what is tranmission

movement of a signal from the site of pain to the spinal cord and brain

14

what is perceptions

synthesis and analysis in the brain

15

what is modulation

endogenous systems in place that can inhibit pain at any point along the pathway

16

what are nociceptors

free nerve endings that can distinguish between noxious and innocuous stimuli

17

what are some substances released from traumatized tissue that cause pain

bradykinin
serotonin
substance P histamine * inflammation
prostaglandin*

18

what do the substances released from traumatized tissues cause

sodium influx and depol
facilitates movement of pain impulse to spinal cord

19

what are two drugs that inhibit transduction

NSAIDS minimize prostaglandin production
corticosteroids inhibit prostaglandins and other inflammatory mediators

20

how is pain transmitted

damage - nerve - spinal cord - brain stem - thalamus - central structures of brain where processed

21

describe the a delta pain fibers

large diameter so can be transferred very fast and immediately can withdraw from painful stimulus to prevent further damage

22

describe the c pain fibers

small diameter slower causes immobilization healing and behavour modification

23

where is pain perceived

cortical structures

24

how is modulation mediated

endorphins reduce pain sensation and neurotransmitters

25

where do endorphins come from

descending fibers in spinal tract and hihger cortical centers released when pain impulse reaches brain binds to receptors in pain pathway to block transmission

26

what activates the descending pain modulation system

stress
fear
hunger
thirst
fatigue
prolonged motor activity
hypnosis

27

what drugs block transduction

nsaids
antihistamines
membrane stabilizing agents
local anesthetic cream
opioids
bradykinin and serotonin antagonists

28

what drugs block modulation

spinal opiods
alpha2 agonists
NMDA receptor antagonists
anticholinesterases
nsaids
cck antagonist
NO inhibitos
k channel openers

29

what drugs block transmission

local anesthetics

30

what drugs block perception

parenteral opiods
alpha 2 agonists
anesthetics

31

what is nociceptive pain

injury
trauma
infection

32

what is neuropathic pain

damage or dysfunction of peripheral or CNS

33

what is visceral pain

arises from an internal organ

34

wht is hyperalgesia

intense pain in response to mildly painful stimulus

35

what is allodynia

pain in response to completely innocuous stimulus

36

what are theffect caused by inhibition of prostaglandins by nsaids

analgesic
antipyretic
anit inflammatory

37

what does cox-1 do

found in many cells constantly maintain stomach lining and many critical functions

38

what does cox-2 do

induced in immune cells
cause pain inflammation and fever

39

what are the 3 phases of inflammation

1. acute transient -vasodilate, cap permeability
2. delayed subacute phase - leukocytes and phagocytes
3. chronic proliferative phase - tissue degeneration and fibrosis

40

what do prostaglandins do upon cell damage

released cause local inflammation and pain

41

how can prostaglandins be used in birth

cause uterine cramping to injection to abort and inibitos to delay delivery

42

what other effects do prostaglandins have

platelet aggregation formation of clots - ASA
modulate stomach acidity and mucous lining - NSAIDS

43

how does aspirin work

irreversibly acetylates COX enzymes so effect lasts as long as it takes to replace the enzyme

44

how is caffiene used as a coanalgesic

60-120mg will increase the analgesic effect of all non opiod analgesic drugs

45

what are signs and symptoms of salicylate overdose

tinnitus***
increase in metabolic rate burns glucose and oxygen causing increased co2 - initial hyperventilation, metabolic acidosis, sever hypoglycemia

46

what are the immediate dangers of salicylate overdose

hyperthermia
deydration
hypoglycemia

47

treatment of salicylate overdose

parenteral fluids and glucose
keep cool

48

salycilates

methylsalicylate - oil of wintergreen
bismuth salicylate (peptobismol)
aspirin

49

proprionic acids

ibuprofen
naproxen

50

diclofenac

high potency and GI bleed risk
prescriptions for inflammation pain such as arthritis

51

indomethacin

gout pain and swelling
less common for chronic conditions

52

GI side effects

cox- 1 makes PGE2 and PGI1 which suppresses acid production, increases gastric blood flow, and increases secretion of mucin so non selective cox inhibitors increase acid and reduce mucous

53

misoprostol

prostaglandin analog that supplies stomach with prostaglandin effect lost with non sleective COX inhibitors - not very effective and more likely to cause diarrhea

54

what is reyes syndrome

fetal hepatic encephalopathy (liver induced brain disease) in children with viral infection, associated with SAS

55

nsaids and hypertension

increase in circulating volume

56

nsaids and bleeding disorders

inhibition of COX decreases ability to make clots
interferes with alcohol and warfarin

57

what were the results of a cox2 selective inhibitor

strokes and heart attacks due to the inhibition of prostocyclin

58

how is acetaminophen different

centrally acting analgesic
no ceiling effect
not anti-inflammatory

59

what happens in acetaminophen overdose

metabolized by GSH an antioxidant and at high levels depletes it causing oxidative damage to liver cells and direct damge to liver from the highly reactive intermediate

60

signs of tylenol overdose

elevated serum transaminase levels
hepatic encephalopathy
jaundice - too late

61

symptoms of migraine

throbbing!
nausea
preceded by aura
variable duration and incidence

62

whos more prone to migraines

more common in boys than girls adn reverses after puberty

63

triggers of migraines

weather
missing a meal
stress
alcohol
food
menses

64

phases of a migraine

prodrome - feeling
aura - visual
headache and associated features
postdrome - exhausted

65

how do you treat an acute headache

nsaids
combo with caffiene and ice water
try avoid triggers

66

ergot alkaloid cautions

serotonin agonists
liver disease
rebound headache
cadriovascular disease - vasoconstrict
poor peripheral circulation

67

what are the triptans

agonists at serotonin receptors
side effect similar to ergot alkaloids
relieve nausea and headaches

68

why cant you take triptans with antidepressants

serotonin syndrome both increase serotonin
restless, twitches, sweatingm shivering, tremor

69

how can beta blockers be used in migraine prevention

propanalol regulates blood flow, reduces blood pressure
may cause tiredness, dizzyness

70

how can you use amitryptiline for migraine prevention

lower doses than in depression
may cause dry mouth and eyes, drowsiness

71

drugs for migraine prophylaxis

beta bloackers
TCAs
gabapentin
candesartan
some dietary supplements