Week 2 - Lecture 3 - Clinical Models Flashcards

1
Q

burn injuries

A

caused by a trauma injury
burn injuries cause an inflammatory response
- in the skin
- in other integumentary structures

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2
Q

6 functions of the skin

A

protection : 1st line of defence -physical barrier
body temperature regulation
cutaneous sensation
metabolic functions (vitamin D activation)
blood reservoir
excretion

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3
Q

Burn pathophysiology

A

burns are caused through
direct contact with excessive heat, radiation, caustic chemicals or electricity
- heat will denature proteins causing irreversible cellular damage

all burns result in acute inflammatory response

burn severity is correlated with exposure type and time of the affected surface area

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4
Q

Burn pathophysiology classification

A

superficial partial thickness (first degree)

epidermal damage only
vasodilation of dermal blood vessels
increased capillary permeability
- localised redness, warmth, oedema (swelling) pain

do not result in cell necrosis or scarring

extracellular matrix remains intact

healing is rapid

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5
Q

Deep partial thickness( second degree) burns

A
epidermal and upper dermal damage
epidermal and dermal layers separate 
- fluid accumulates, blisters appear
loss of function: 1st line of defence
Tissue necrosis are common, tissue fibrosis, scarring
healing occurs within 2-4weeks
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6
Q

Full thickness (3rd degree) burns

A

entire thickness of skin involved
-epidermis, dermis, subcutaneous
skin gray- white, cherry red, or blackened
not painful (nerve ending destroyed)
healing is difficult due to extensive tissue loss
skin grafting usually necessary
regeneration of epithelial cells impaired
scarring is extensive
loss of elasticity leads to contractors

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7
Q

loss of skin function: multiple complications (in severe burns)

A
microorganism invasion
-infection
body fluids shifts 
- impaired blood circulation, oedema (swelling) 
dehydration and electrolyte imbalance 
- leads to renal shutdown and circulatory shock 
overwhelming metabolic demand 
- increased risk of malnutrition
temperature regulation problems
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8
Q

Burn pathophysiology cont’

A

significant hemodynamic changes - changes in the flow of blood in tissues and organs

poor perfusion

  • problematic for vital organs
  • constant flow of oxygen required

inadequate blood in circulation can lead to hypovolemic shock

fluid volume replacement required

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9
Q

Access for microorganisms in burns means

A

significant risk for sepsis development
- bacterial infection of the blood
significant risk for septic shock
- massive inflammatory response due to bacterial toxins in blood

in full thickness burns : dead tissue and exudate convert into an eschar

  • thick coagulated crust made from dead skin
  • requires surgical removal to prevent further microorganism growth within the dead tissue

extensive demand on metabolic and reparative processes

  • increased energy, oxygen, protein needs
  • not sufficient nutrients available will lead to tissue wasting, hypoxia and infection
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10
Q

burn diagnosis

A

wound depths are classified according to the affected tissue layers

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11
Q

brun clinical manifestations

A

depend on depth of burn injury

superficial- partial thickness burns show the 5 signs of inflammation

deep partial thickness burns
- blistering occurs, erythema, pain, oedema, serous exudate

full thickness burns

  • erythema, eschar, oedema, exudate
  • destroyed nerve endings inhibit pain response from burn penetration area
  • not pain free : nearby tissue suffer from partial thickness burn
  • pain perception according to bull’s eye
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12
Q

surface area of 9

A

slide 15

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13
Q

critical burn if

A

> 25% of body has second degree burns or
10% of body has third degree OR
if the face, hands, feet or respiratory passages bear third degree burns

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14
Q

burn treatment

A

increased survival rates

minor and moderate burns

  • remove source of injury
  • stop burning process
  • chemical burns flushed with plenty of water
  • wound can be cleared with water
  • antimicrobial ointment applied
  • dressing

changing dressing frequently helps debridement

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15
Q

what is debridement

A

the mechanical removal of debris and necrotic tissue

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16
Q

burn treatment for moderate and major burns

A

emergency medical admission
includes any third degree burns to the face, hands, feet or respiratory system

respiratory passageway burns may lead to suffocation
-specialised intervention

initial focus
-stabilise airways, breathing and circulation
- fluids : replace water and sodium, restore circulation
nutrition: increased metabolic demand
antibiotics : infection
analgesics : pain management

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17
Q

wound management for major burns

A

removing necrotic tissue
closing wounds
preventing infection
hydrotherapy to cleanse the wound, remove dead tissue and exudate
skin grafting for full thickness burns
- full thickness burns use the replacement healing process
- unable to undergo re-epithelialisation
-transplanted tissue supports cellular regeneration
-decrease infection
-minimise scarring

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18
Q

long term rehab (tertiary prevention)

A
severe scarring
contractures (shortening and hardening of tissues) 
deformity and immobility 
chronic pain 
depression, psychological issues
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19
Q

What is arthritis

A

inflammatory disorders that involves damage to articular cartilages of synovial joints

acute forms of arthritis : caused by bacteria via traumatic joint wound - treated with antibiotics

arthritis caused by chronic inflammation
- RA
-Gouty arthritis
OA is not caused by inflammation

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20
Q

function of synovial joints

A

articulation : site where two or more bones meet
function of joints
-give skeleton mobility
-hold skeleton together

synovial joints

  • highly vascular
  • two layer synovial membrane
    • connective tissue layer
    • synovial cell layer : fluid production
  • bone separated by fluid filled joint cavity
  • freely movable
  • include limb joints; most joints of body

common target for inflammation

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21
Q

RA pathophysiology

A

RA is systemic autoimmune disease
chronic inflammation of synovial membranes and synovial hyperplasia
-increased synovial fluid production
-swelling and thickening of synovial membrane
-joint erosion
-pain

onset between 36-50 years

RA affect 0.8% of adults worldwide
F= 3x more

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22
Q

autoimmune =

A

the immune system attacking healthy tissue

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23
Q

Etiology of RA

A

involves a combination of

  • genetic susceptibility
  • environmental factors are also linked to RA (eg. smoking, infections)
  • immune triggering event (currently unknown)
  • subsequent autoimmunity against synovial cells

lymphocytes and plasma cells (WBCs) in the synovial membrane and cartilage produce antibodies
- our circulating antibodies in our immune system bind to these antibodies(or other antigens or proteins in the synovial membrane)
these complexes of antibodies and antigens form immune complexes and present in the synovial
these immune complexes trigger the complement system and exaggerate the inflammatory response

24
Q

excess production/release of inflammatory mediators means

RA patho

A

vascular response/cellular response of inflammation
production of destructive enzymes, health tissue damage
synovial cells adapt to this damaging environment through rapid regeneration ( hyperplasia)

25
Q

synovium is altered and causes what

RA patho

A

mild oedema
accumulation of cells of chronic inflammation
acceleration of angiogenesis (new blood vessel formation)
accumulation of fibrin (fibrous protein in connective tissue)

At this point, minimal damage to the joint

26
Q

remissions and exacerbations for RA

A

pannus formation : granulation tissue

  • formed over inflamed synovium
  • pannus produce enzymes that break down cartilage and erode adjacent bone
  • irreversible erosion process

Fibroblasts try to replace damaged connective tissue layer : lead to fibrosis in the joint capsule
-impaired and debilitating fixation of joint : ankylosis

limited joint movement leads to decreased workload – muscle tissue atrophy

inflammatory cells irritate surrounding muscle
- muscle spasm

27
Q

RA clinical manifestations

A
Most RA inset is insidious 
Severity : mild to debilitating 
joint swelling is symmetric and widespread 
- any number of joints 
pain and stiffness 
redness, heat and swelling 
decreased mobility 

malalignment/deviation is common for long standing RA
-combination of cartilage, bone erosion and fibrosis

systemic manifestations during exacerbations

  • low grade fever, fatigue, anorexia, weight loss, weakness
  • granulomas (nodules) can form on blood vessels
28
Q

RA diagnostic criteria

A

no definitive test

history and P/E 
-morning joint stiffness lasting over 1 hour
arthritis of 3 or more joints areas
arthritis of the hand joints 
symmetric arthritis 
rheumatoid nodules 

several diagnostic tests
increased likelihood with positive findings:

Erythrocyte sedimentation rate (ESR) : elevated
C-reactive protein (CRP) : elevated
Presence of rheumatoid factor (IgG)
Presence of antinuclear antibodies (ANA)
Presence of inflammatory products
in synovial fluid
radiographic visualisation of joint damage

many of the tests are not specific
-false positives and false negatives

29
Q

RA treatment

A

balance between pharmacologic and non-pharmacologic approach

pharmacologic :
-drugs that induce remission
-anti-inflammatory drugs (NSAIDs)
Immunosuppressant drugs (DMARDs- disease modifying antihirheumatic drugs)

Non-Pharmacologic

  • rest/activity balance (to suppress inflammation)
  • physical therapy exercises to promote joint mobility, physiotherapy
  • splints to allow joint to rest and prevent deformities
  • heat/cold therapy (to suppress inflammation)
  • surgery : synovial membrane removal, joint replacement
30
Q

function of the stomach

A

organ of protection : first line of defence
-very acidic environment - pH 1.5-3.5
digestion
-gastric secretions
- mucus, gastric acid, enzymes, hormones, intrinsic factors

absorption: water and alcohol

cells form tight junction
- protect tissues against corrosive gastric acid

31
Q

acute gastritis

A

inflammation in the gastric mucosa

cause :
ingestion of irritating substances (medications, alcohol, microorganisms)
-develops over short period
-reversible if causative agent removed

32
Q

acute gastritis pathophysiology

A

ingestion of irritating substances and/or poor gastric perfusion results in acute inflammation of the gastric mucosa

gastric epithelial cell become necrotic

gastric acid erodes underlying tissue

acute inflammatory response

  • mild erythema (redness)
  • severe gastric perforation
  • gastric acid escape and corrodes nearby tissue
33
Q

acute gastritis clinical manifestations

A
dependant on severity
- mild to severe abdominal pain
-ingestion (heartburn) 
loss of appetite 
nausea
vomiting  
mild haemorrhage and vomiting blood

severe haemorrhage and perforation : lead to shock and medical emergency

34
Q

Acute gastritis diagnosis

A

history and P/E

  • medication taking (aspirin/NSAIDs) alcohol, contaminated food
  • other potential causes of ischemia
  • abdominal tenderness

endoscopic examination : presence ulcers in the mucosa

stool analysis (presence of blood in stool)

haemoglobin/ hematocrits level, complete blood count (anaemia)

35
Q

Acute gastritis treatment

A

prevent the injury (discontinue ingestion of irritating substances)
buffer or decrease production of gastric acid
prognosis is good

36
Q

chronic gastritis

A

unrelenting injury

  • chronic infection : helicobacter pylori
  • autoimmunity

Gastric epithelial and mucosal cell atrophy

gastric acid production impaired

37
Q

helicobacter pylori is most prevalent

A

asia
developing countries
50% of world’s population has been infected
pathological effect occur in 10-20% infected individuals

38
Q

H. Pylori : gram negative bacteria

A

person to person, saliva, stool
ingested and multiplies on epithelial surface and mucus barrier
produce enzyme that neutralises the pH 1.5-3.5 gastric acid
H. pylori survives and produces toxin
toxins destroy mucosal barrier - injury

39
Q

intense inflammation triggered (CG pathophysiology)

A

neutrophils, macrophages try to contain the infection
ongoing phagocytosis, immune response triggered
H.Pylori is contained in the epithelial cells
- no erosion of the gastric mucosa
-epithelial cells and glands adapt and atrophy
-gastric acid production and secretion is impaired

40
Q

Chronic gastritis autoimmune pathophysiology

A

parietal cell secrete HCI)
- antibodies against parietal cells : gastric acid secretion impaired

intrinsic factor (IF) is needed for B12 absorption
-antibodies against IF: B12 absorption is impaired
- B12 required to promote DNA synthesis in RBCs
impaired DNA synthesis – decrease in RBCs
Low haemoglobin levels
-pernicious anaemia (pernicious = deadly)

41
Q

chronic gastritis clinical manifestations

A
H.Pylori infection 
- most infected : symptomatic carrier 
  - pathological effect occur in 10-20% of infected individuals 
-dyspepsia (vague discomfort of the upper abdomen or chest) 
nausea 
heartburn 
loss of appetite 
vomiting 

autoimmune

  • can be asymptomatic
  • first sign : pernicious anaemia (deficiency in intrinsic factor, unable to absorb B12, abnormal RBCs production)
  • – weakness, fatigue, light-headedness
  • dyspepsia, vague abdominal pain, vomiting, anorexia, nausea
42
Q

Chronic gastritis diagnosis

A

H.Pylori

  • endoscopic examination
  • biopsy of gastric tissue
  • breath test for presence of a specific enzyme
    • H.Pylori breaks urea into NH3 and CO2
    • CO2 content measured
  • Presence of antibodies in blood

autoimmune

  • biopsy of gastric tissue and histologic examination
  • antiparietal or anti-intrinsic factor antibodies in blood
      • existing autoimmune process
  • low B12 level in blood
43
Q

Chronic gastritis treatment

A

H.Pylori infection

multiple antibiotics for chronic infectious processes
proton pump inhibitors (raise pH) to help healing

H.Pylori can lead to chronic ulcers and gastric cancer

Autoimmune

  • immunosuppressive drugs
  • administration of B12 intramuscularly
  • autoimmune gastritis can lead to gastric cancer
44
Q

inflammatory bowel disease (IBD)

A

chronic, relapsing inflammatory bowel disorders of unknown origin (idiopathic)

  • genetic aetiology
  • autoimmunity (immune reactions to intestinal flora)
  • alterations of epithelial barrier functions
  • abnormal cell responses in the immune system

most common in small and large intestines
-can occur anywhere in the GI tract

most common form of IBD

  • Crohn’s disease
  • ulcerative colitis
45
Q

Function of the small intestine

A

primary function : digestion and absorption

  • enzymes of villi : digestion
  • epithelium of mucosa : absorption
  • lamina propria : infection-fighting, immune response
  • Labile cells : cells divide
46
Q

Crohn’s disease pathophysiology

A

idiopathic chronic inflammatory disease
-family history, environmental factors (smoking, diet, microorganisms)
affects any part of the digestive tract from mouth to anus
most common in small intestine
recurrent condition

47
Q

cont’ pathophysiology of Crohn’s

A

28000 in australia
non-continuous penetrating ulcerations and fibrosis (skip lesions)
ulcerations can produce longitudinal and transverse inflammatory tissues that extend into the lymphatics

48
Q

Crohn disease patho pt. 3

A

inflammation begins in the mucosa and submucosa

  • increased permeability and vascular changes
  • oedema and fibrosis
  • cellular response
  • granulomas form to wall off effected areas
    -bowel segment become further inflamed
    -interior surface thicken
  • oedema, fibrosis, granuloma
  • can lead to bowel obstruction
  • ingested food can’t pass through - critical condition
    -ulcers (due to poor perfusion) form and lead to
  • fistula : abnormal passage between 2 segments of bowel or epithelial tissue
  • abscess : pocket of purulent exudate, containing pus
    external surfaces can form adhesions, limiting bowel function
49
Q

Crohn disease clinical manifestations

A
rapid stool transition time 
intestinal oedema 
fibrosis 
loss of absorptive function 
symptoms depend on location of affected area 
- abdominal pain 
- diarrhoea 
-malnutrition 
-blood in stool 
- bowel obstruction 
systemic manifestations 
- fever
- weight loss
- fatigue 
- anaemia may result from malabsorption of vitamin B12 and folic acid
50
Q

Crohn disease diagnostic criteria

A

history and P/E

  • difficult to differentiate from ulcerative colitis
  • similar risk factors and theories of causations as ulcerative colitis

endoscopic examination to check mucosa involvement

radiography/CT to check abscesses, fistulas, obstruction

stool cultures to rule out infection

51
Q

Crohn disease treatment

A

treatment is symptomatic (symptom management)

pharmacologic treatment

  • suppress inflammation
  • suppress immune response

dietary changes

  • acid foods that irritate bowel
  • during exacerbation
  • high in calories and protein
  • low in fat and fibre

surgical treatment

  • remove damaged bowel
  • repairs fistula

increased risk of colorectal cancer

52
Q

ulcerative colitis

A

chronic inflammatory disease of the colon

  • only in large intestine
  • does not affect other GI tract
  • mainly mucosal layer (can extend to submucosa)

idiopathic disease
- suggested causes : infectious, immunologic (anticolon antibiotics), dietary, genetic

australia : around 33000

53
Q

UC pathophysiology

A

chronic inflammation begins in rectum and ascends the descending colon

continous superficial areas of ulcerations (does not skip)
- inflammation invades superficial mucosa : friability (easily bleeds)
mucosa erythematous and granular
hemorrhagic lesions, abscesses, necrotic tissue, ulceration
-repeated cycle of ulceration alternating with the deposition of granulation tissue during the healing phase
- pseudopolyps raised inflammatory tissue

perforation, obstruction, and massive haemorrhaging can result

54
Q

UC clinical manifestations

A

symtoms are related to large intestine irritability and friability
functional losses are related to the extent of inflammation
most common symptoms
- diarrhoea
-rectal bleeding
-abdominal pain

systemic manifestations 
fever
weight loss
fatigue
anaemia
55
Q

UC diagnosis

A

History and PE
-diarrhoea (10 to 20/day) bloody stool, cramping
-severity is based on the number of bowel movement with rectal bleeding
mild- <4 day no systemic manifestations
moderate - >4 day no systemic manifestations
severe - >4 days, systemic manifestations, low blood albumin

endoscopic examination : mucosal erythema (redness)
radiographs
- colonic dilation, ulceration, perforation, obstruction
complete blood count (anaemia)

56
Q

UC treatment

A
treatment is symptomatic (symptoms management)
pharmacologic treatment 
- suppress inflammation 
- suppress immune response 
-antidiarrheal medication 
dietary changes 
- healthy diet (avoid milk, caffeine, spicy food) 
-adequate fluid intake 
Surgical treatment 
- if perforation or obstruction occur

increased risk of colon cancer, higher than crohn’s

57
Q

differential diagnosis crohn;s and UC

A

pg. 58