Hemodynamic Basis of Disease (complete) Flashcards
What is the role of hydrostatic pressure in maintaining body fluid balance?
Pushes fluid from arterial end of capillary to interstitial space
What is the role of oncotic pressure in maintaining body fluid balance?
Essentially plasma protein concentration
When hydrostatic pressure pulls fluid out of arterial end, oncotic pressure increases —» causes fluid to be pulled back into venous end of capillary to balance the [plasma protein]
Define edema
fluid movement from capillaries to adjacent tissue
transudate or exudate
CAUSE: Increased hydrostatic pressure and decreased oncotic pressure
Define effusion
fluid movement from capillaries to body cavity
transudate or exudate
CAUSE: Increased hydrostatic pressure and decreased oncotic pressure
Define hypermia
An active increase in blood flow due to arteriolar dilation
- Brings inflammatory/repair mediators to areas of tissue damage/infection
- Provides ^O2 to exercising skeletal muscle
- Causes a red coloration (erythema) to tissue b/c of ^ mass of oxygenated RBCs
Define congestion
Pathologic accumulation of blood due to impaired outflow of venous blood
- Has red/blue color due to deoxy blood accumulation
- May have increased hydrostatic pressure
What is the underlying etiology of exudate?
Increased vessel permeability due to inflammation — damaged blood vessels
A type of edema/effusion
Is the protein fluid/serum ratio higher in exudate or transudate?
Exudate
Is the LDH fluid/serum ratio higher in exudate or transudate?
Exudate
Is the glucose fluid/serum ratio higher in exudate or transudate?
Transudate
Describe the cells in exudate
Many WBCs
> 1000/microL
What is the underlying etiology of transudate?
Ultrafiltrate of plasma
Increased hydrostatic pressure and/or reduced oncotic pressure
Describe the cells found in transudate
None or few WBCs
<1000/microL
What are the defects that lead to hemorrhage?
1) Damaged blood vessel walls
2) impaired function/low levels of platelets or coag factors
Essentially:
- Because damage exceeds body’s normal hemostatic mechanisms
- hemostatic mechs cannot manage/repair normal levels of damage
Name the key factors (Virchow’s Triad) that are involved in thrombosis
1) endothelial injury
2) abnormal blood flow (stasis or turbulence)
3) hypercoagulability (inherited or acquired)
Thrombosis can occur b/c of 1 or more factors
THINK: out of control clotting
What is the difference between a thrombus and an embolus?
Thrombi are attached to the vessel wall
Emboli are detached/fragmented thrombi (free floating)
Describe disseminated intravascular coagulation (DIC)
- Thrombosis and hemorrhage occur simultaneously
T dominates chronic DIC
H dominates acute DIC
Often presents w/
1) anemia
2) respiratory insufficiency (b/c of small clots in lungs)
3) convulsions (b/c of small clots in brain)
4) acute renal failure (thrombi in glomeruli)
5) shock
Describe white infarcts
- Arterial blockage
- single blood supply
- dense tissue
- organs: kidney, heart, spleen
No reperfusion
No opportunity for hemorrhage
bottomline — NECROSIS!
Describe red infarcts
- Venous blockage
- dual blood supply
- loose tissue
- reperfusion
- organs: lung, liver, intestine
Was an opportunity for hemorrhage
bottomline — NECROSIS!
What is shock? Which types exist?
Occurs when circulating blood volume or pressure is not adequate to perfuse body tissues —»> widespread cell hypoxia
1) Cardiogenic shock
2) Hypovolemic shock
3) Septic shock
Describe cardiogenic shock
Results from failure of heart to pump adequate blood and/or generate adequate blood pressure to perfuse distal tissues
Describe hypovolemic shock
Happens when there’s not enough blood volume to perfuse all tissues
Cardiac output decreases b/c of low blood return to heart
Vasoconstriction, ^HR, renal conservation of fluid
Describe septic shock
B/c of systemic inflammation (SIRS)
Micro infections —» high levels of inflammatory mediators —» arterial vasodilation, vascular leakage, venous pooling
Hypotension, decreased tissue perfusion
What are the sources/causes of thromboemboli of the venous style?
Deep leg veins
also, arm veins (but less come than legs)
Most common emboli of right side/venous circulation
Which organs are affected by thromboemboli of the venous style?
Lungs
What are the clinical outcomes of thromboemboli of the venous style?
Respiratory insufficiency
Chest pain
What are the sources/causes of fat/BM emboli?
Long bone fractures (think leakage!)
These cause vein damage
Which organs are affected by fat/BM emboli?
Lungs
What are the clinical outcomes of fat/BM emboli?
Respiratory insufficiency 1-3 days post-trauma (bone breaking)
mental status changes!
What are the sources/causes of amniotic fluid emboli?
Torn placental membranes
Uterine vein rupture
Which organs are affected by amniotic fluid emboli?
Lungs
Brain
Vasculature
What are the clinical outcomes of amniotic fluid emboli?
Respiratory insufficiency, shock, seizures — all during labor or immediately post-partum
Causes 10% of maternal deaths
What are the sources/causes of thromboemboli of the arteriole style?
Heart (vegetations/mural thrombi)
Aorta, carotid artery
Which organs are affected by thromboemboli of the arteriole style?
Legs (75%)
Brain (10%)
No idea what happened to the other 15%
What are the clinical outcomes of thromboemboli of the arteriole style?
Stroke
Tissue necrosis in the leg
What are the sources/causes of atheroemboli?
atherosclerotic plaque of the aorta, iliac, carotid arteries
Which organs are affected by atheroemboli?
- Legs
- Brain
- GI tract
- Kidney
What are the clinical outcomes of atheroemboli?
- Stroke
- Tissue necrosis in the leg
- GI pain/bleeding
- Acute kidney injury
Most common emboli of left side/arteriole circulation
Which organs are generally affected by emboli in the right side/venous circulation?
Da lungs!
Which organs are generally affected by emboli in the left side/arteriole circulation?
Pretty much any organ
More commonly, legs or brain
