Edema, Hemorrhage, Congestion and Shock Flashcards
edema
increased fluid in the extracellular matrix
hyperemia
increased flow
congestion
increased backup
hemorrhage
extravasation
hemostasis
keeping blood as a fluid
thrombosis
clotting blood
embolism
downstream travel of a clot
infarction
death of tissues w/o blood
shock
circulatory failure/collapse
fluid collection in lung
hydrothorax
fluid collection in heart
hydropericardium
fluid collection in abdominal cavity
ascitis
fluid collection in entire body
anascara
mechanism of edema
- increased vascular hydrostatic pressure
- decreased plasma oncotic pressure
- lymphatic obstruction
- sodium and water retention
- inflammation
increased hydrostatic pressure due to
impaired venous return
impaired venous return due to
- congestive heart failure/constrictive pericarditis
- cirrhosis of liver
- venous obstruction or compression by thrombosis, external pressure or LE inactivity
mechanism of congestive heart failure
heart not pumping blood effectively causing backing of blood in veins
mechanism of cirrhosis of liver
scarring of liver impairs return of blood through portal vein, increased back pressure in smaller veins causes ascites
mechanism of venous obstruction
back up of blood causes edema of surround tissues
arteriolar dilation caused by
- heat
- neurohumoral dysregulation
reduced plasma oncotic pressure leads to
protein losing glomerulopathies - leaky capillaries cause loss of albumin
causes of reduced plasma oncotic pressure
- liver cirrhosis - reduced albumin synthesis
- malnutrition
- protein losing gastroenteropathy
lymphatic obstruction leads to
impaired lymphatic drainage - lymphedema
causes of lymphatic obstruction
- inflammatory
- neoplastic
- postsurgical
- postirradiation
examples of lymphedema
- filiariasis causing elephantiasis
- irradiation of breast and axilla for treatment of breast cancer causing upper limb edema
sodium and water retention
excessive water intake with renal insufficiency
increased tubular reabsorption of sodium (salt) occurs in
-renal hypoperfusion
increased oncotic pressure
increased salt retention causes water retention and leads to
- increased hydrostatic pressure (due to intravascular fluid volume expansion)
- decreased vascular colloid osmotic pressure (due to dilution)
subcutaneous edema caused by
cardiac or renal disease
pulmonary edema
impedes oxygen diffusion
brain edam caused by
herniation of brain stem or impedes vascular supply to brain stem
transudate
Protein and cell poor fluid
Specific gravity: less than 1.012
Protein content: less than 3 gms/dl
Lactic dehydrogenase low
example of transudate
cardiac failure and decreased protein levels
exudate
Protein and cell rich fluid
Specific gravity: more than 1.012
Lactic dehydrogenase high
example of exudate
inflammation
where does dependent edema occur
in extremities and gravity prone areas of body
ex. heart failure
pitting edema
When skin and underlying soft tissues with edema are compressed with fingers, the impressions remain
pitting edema is associated with
heart failure and is transudate
hypermeia and congestion caused by
locally increased blood volumes
hyperemia
- active process of arteriolar dilation
- increased blood flow leading to erythema
example of hyperemia
inflammation, muscle during exercise
types of congestion
- passive process
2. cyanosis
passive process of congestion
reduced outflow of blood from a tissue
cyanosis of congestion due to
red cell stasis and accumulation of deoxygenated Hb
chronic passive congestion caused by — heart failure
left
left heart failure causes back up of blood in
lungs –> lack of blood flow –> chronic hypoxia –> schema tissue injury and scarring
what are heart failure cells
hemosiderin-laden macrophages found in alveoli
acute hepatic congestion
- distended central vein and sinusoids
- ischemic centrilobular hepatocytes
- fatty change in periportal hepatocytes
chronic passive congestion caused by – sided heart failure
right
right sided heart failure causes blood to backup in
liver bc R ventricle is unable to pump blood out efficiently
gross appearance of chronic passive congestion of liver
centrilobular regions red-brown and slightly depressed; accentuated against zones of uncongested tan liver (nutmeg liver)
microscopic appearance of chronic passive congestion of liver
sinusoidal dilation, centrilobular hemorrhagic necrosis
hemorrhage
extravasation of blood into the extravascular space
hematoma
hemorrhage contained within a tissue
petechiae
minute 1-2 mm hemorrhages into skin, mucous membranes or serosal surfaces
petechiae are associated with
locally increased intravascular pressure, low platelet counts of defective platelet function
purpura
hemorrhages > 3 mm
pupura can be associated with
same disorder that cause petechia
-can be secondary to trauma, vasculitis or increased vascular fragility (eg. amyloidosis)
ecchymoses
larger (>1 -2cm) subcutaneous hematomas due to trauma
ecchymoses color change caused by
macrophages phagocytize RBCs; hemoglobin (red-blue color) –>converted into bilirubin (blue-green color) –> hemosiderin (gold-brown color)
clinical significane of hemorrhage depends on
- volume and rate of bleeding
2. site of hemorrhage
large volume and rate of bleeding can cause
hemorrhagic (hypovolemic) shock
intracranial hemorrhage causes increase in
pressure compromising blood supply or cause herniation of brainstem
chronic or recurrent external blood loss can cause
anemia
eg. peptic ulcer, menstrual bleeding
hemothorax
hemorrhage in pleural cavity
hemopericardium
within pericardial sac
hemoperitoneum
within peritoneal cavity
shock is characterized by
systemic hypotension due to reduced cardiac output or reduced effective circulating blood volume
consequence of shock
impaired tissue perfusion and cellular hypoxia
cardiogenic shock due to
failed pumping of blood by heart
hypovolemic shock
loss of blood or plasma volume (massive hemorrhage, fluid loss from severe burns) leads to low volume of blood for circulation
septic shock results from
vasodilation and peripheral pooling of blood in bacterial or fungal infections
septic shock is associated with
severe hemodynamic and hemostatic derangements
at risk patients for septic shock
diabets
immunocompromised
septic shock most frequently triggered by gram – bacteria
positive
mechanism of septic shock
- free lipopolysaccharide released by degraded bacteria binds to LPS binding protein and CD14 on monocytes and macrophages
- causes increased levels of IL-1, IL-6, TNF, IL-8
septic shock can lead to
- systemic vasodilation
- decreased myocardial contractility
- endothelial injury
- activation of coagulation system
metabolic abnormality of septic shock
- insulin resistance and hyperglycemia
- pro-inflammatory cytokines suppress insulin release while simultaneously promoting insulin resistance
- hyperglycemia decreases neutrophil function- suppressing bactericidal activity
in septic shock initially there is an acute surge in
glucocorticoid production, then there is adrenal insufficiency and a function deficit of glucocorticoids from depression of adrenal glands or frank adrenal necrosis due to DIC
organ dysfunction of septic shock caused by
- Systemic hypotension, interstitial edema, and small vessel thrombosis
- High levels of cytokines and secondary mediators can decrease myocardial contractility and cardiac output
increased vascular permeability and endothelial injury can lead to
adult respiratory distress syndrome
severity and outcome of septic shock depends on
extent and virulence of infection, immune status of host, presence of other co-morbid conditions and pattern and level of mediator production
treatment of septic shock
- antibiotics
- intensive insulin therapy for hyperglycemia
- fluid resuscitation to maintain systemic pressures
- corticosteroids to correct relative adrenal insufficiency
clinical presentations of septic shock
Increased respiratory rate, increased heart rate, low blood pressure, fever, chills oliguria, warm skin, confusion
toxic shock syndrome caused by
toxin A
-superantigen causes septic shock by widespread nonspecific activation of T cells
clinical presentations of septic shock
Increased respiratory rate, increased heart rate, low blood pressure, fever, chills oliguria, warm skin, confusion
neurohumoral mechanisms maintain cardiac output and BP by
- baroreceptor reflexes
- catecholamine release
- renin-angiotensin axis
- antidiuretic hormone release
- sympathetic stimulation – body trying to maintain proper tone of vessel
if shock continues and underlying causes are not corrected, shock progressive into
progressive phase
neurohumoral mechanisms maintain cardiac output and BP by
- baroreceptor reflexes
- catecholamine release
- renin-angiotensin axis
- antidiuretic hormone release
- sympathetic stimulation – body trying to maintain proper tone of vessel
if shock continues and underlying causes are not corrected, shock progressive into
progressive phase
irreversible stages of shock causes
- lysosomal enzyme leakage
- worsening myocardial contractile function
- ishcemic bowel which may allow intestinal flora to enter circulation = may lead to bacteremic shock
- acute tubular necrosis of kidney
effects of lactic acidosis
lowers tissue pH and blunts vasomotor response
-arterioles dilate and blood beings to pool in the microcirculation
irreversible stages of shock causes
- lysosomal enzyme leakage
- worsening myocardial contractile function
- ishcemic bowel which may allow intestinal flora to enter circulation = may lead to bacteremic shock
- acute tubular necrosis of kidney
shock affects GI by causing
- acute gastric petechial haemorrhages
- ulcers
- intestinal ischemia in border zones
shock affects DIC
- fibrin-rich microthrombi in various organs
- consumption of platelets and coagulative factors
shock affects GI by causing
- acute gastric petechial haemorrhages
- ulcers
- intestinal ischemia in border zones
shock affects brain causing
global hypoxia ischemic encephalopahy (red neurons - dead neurons with red cytoplasm nd pyknotic nuclei)
shock affects heart causing
contraction band necrosis
shock affects kideny by
acute tubular necrosis
shock affects liver by
centrilobular necrosis
shock affects kideny by
acute tubular necrosis
neurogenic shock caused by
anesthetic accident of spinal cord injury
neurogenic shock causes
causes loss of vascular tone and peripheral pooling of blood
anaphylactic shock caused by
IgE-mediated hypersensitivity reaction
anaphylactic shock causes
widespread vasodilation, tissue hypoperfusion and hypoxia