Fluid and Hemodynamic Disorders, Thrombosis, and Shock Flashcards
Define edema
increased interstitial fluid
Increased hydrostatic pressure, reduced plasma osmotic pressure, lymphatic obstruction, sodium retention, and inflammation are all causes of what?
edema
Describe the effects on veins and arteries associated with increased hydrostatic pressure
veins: impaired venous return (can cause thrombus)
arteries: arteriolar dilation (causes heat and neurohumural dysregulation)
What are the results of reduced plasma osmotic pressure?
protein-losing glomerulopahties
cirrhosis
malnutrition
protein-losing gastroenteropathy
When sodium retention occurs, renin-angiotensin-aldosterone secretion ____
increases
Activation of the renin-angiotensin system in association with sodium retention causes a ____ in blood volume
increase in blood volume = edema
This is an active process; defined as arteriolar dilation that leads to increased blood flow and engorgement of vessels with oxygenated blood
hyperemia
This is a passive process; defined as reduced outflow of blood which causes an increased volume of deoxygenated blood, increased pressure, and stasis
congestion
Define hemorrhage
a release of blood into the extravascular space
Hemorrhages have specific names depending on their size. For the following sizes, give the associated name.
1-2 mm
> 3 mm
> 1-2 cm
1-2 mm = petechiae
> 3 mm = purpura
> 1-2 cm = ecchymoses
Factor 12 activates coagulation cascade to generate ____ which converts fibrinogen to fibrin to form a meshwork to stabilize the _____ ____
thrombin; platelet plug
In regards to thrombosis, what is Virchow’s triad?
endothelial injury, abnormal blood flow, hypercoagulability
Arterial thrombi typically occur at sites of ___ injury, while venous thrombi occur in sites of ____ and are almost always ___
endothelial; stasis; occlusive
Thrombi on heart valves are “_____”
vegetations
Thrombi are usually attached to their origin and tend to propagate towards the ____
heart
The propagating tail of a thrombus may not be very firm and may fragment, causing ____
emboli
This is a detached intravascular solid, semisolid, or gaseous mass carried by the blood to a site distant from the point of origin
emboli
These emboli are usually from marrow of broken long bones. They are sometimes accompanied by a rash and can be seen in various organs, along with marrow elements, following CPR
fat emboli
This type of embolism can be a consequence of decompression sickness from gas bubbling in tissues. The most common iatrogenic cause is introduction of > 100 cc air into a vessel during a procedure
air embolism
This type of embolism is a grave but uncommon complication of labor. It has a 80% mortality rate and is caused by rupture of membranes and uterine vessels.
amniotic fluid embolism
Definition: coagulation necrosis corresponding to a particular vascular distribution caused by either arterial or venous occlusion
infarct
This type of infarct is generally venous, found in “loose” tissues/tissues with dual circulation (lung, liver, bowel), found in congested tissues, and can occur when flow is re-established to a site of previous occlusion and necrosis
red (hemorrhagic) infarct
This type of infarct is generally arterial and found in more “solid” organs
white (occlusive) infarct
This is formation of widespread microvascular thrombi after activation of coagulation cascade by tissue factor or a mimic.
Disseminated Intravascular Coagulation (DIC)
In regards to DIC, the fibrinolytic system responds by degrading newly formed fibrin. This leads to what?
consumptive coagulopathy (defect in coagulation) and bleeding diathesis (susceptibility to bleeding)
Which clinical symptoms of Thrombotic Thrombocytopenia Purport/Hemolytic Uremic syndrome overlap with DIC?
preeclampsia, HELLP, malignant hypertension, and vasculitis
The difference between other syndromes dealing with coagulation, and DIC is the composition of the thrombi. explain
DIC: fibrin
other syndromes: platelets
This represents circulatory collapse with resultant hypo-perfusion and decreased oxygenation of tissue.
shock
What are the two causes of shock?
- decreased cardiac output (hemorrhage, heart failure)
2. widespread peripheral vasodilation (sepsis, trauma)
This type of shock is due to circulatory collapse resulting from the acute reduction in circulating blood volume
hypovolemic shock
This type of shock is due to circulatory collapse resulting from pump failure of the left ventricle
cardiogenic shock
This type of shock is most often associated with severe trauma and reactive peripheral vasodilation
neurogenic shock
This type of shock is most often associated with gram-negative infections, and significant peripheral pooling of blood from peripheral vasodilation results in relative hypovolemia and impaired perfusion
septic shock
A group of toxic molecules called _____ produce septic shock-like manifestations. The release of these molecules occurs in Toxic Shock Syndrome - s. aureus infection
superantigens
Describe the irreversible stage of shock
organ damage and metabolic disturbances are so survive that survival is not possible
Describe the morphologic manifestations associated with shock
kidney: acute tubular necrosis
liver/brain: necrosis
heart/liver: fatty change
colon: mucosal hemorrhages
