Hemodynamics, DIC and shock Flashcards
The starling hypothesis
The flow of fluids across capillary walls depends on the balance between the force of blood pressure on the walls
Describe the pathophysiology of edema
Inc hydrostatic pressure Reduced oncotic pressure Sodium retention Lymphatic obstruction Inflammation
What would you see in a sample of transudate?
Dec protein concentration, clear color, not WBCs
What would you see in a sample of exudate?
Inc protein content and inc WBCs (neutrophils)
What is a subfalcine herniation?
First herniation in hydrocephalous
where does an uncinate hernia enter into?
Foramen magnum
What is the most dangerous hernia which moves into the spinal cord?
Tonsiliar herniation
Lymphedema
Blockage in the lymphatic system leading to swelling
Hyperemia
Active process resulting from augmented tissue inflow because of arteriolar dilation causing a red color
Congestion
Passive process resulting from impaired tissue outflow causing a blue-red color (cyanosis)
Hemorrhage
Extravasation of blood due to vessel rupture (internal or external to tissue)
Hematoma
Accumulation of blood within tissues
Petechiae
Minute hemorrhages into skin, mucous membranes or serosal surfaces
Larger endothelial hemorrhages similar to petechiae are called;
Purapura
What are the steps in hemostatsis?
- Vasoconstriction
- Primary hemostatis
- Secondary hemostatis
- Thrombic events
What are the factors of the intrinsic pathway?
8, 9, 11, 12, prekallikrein, HMWK
What are the factors in the extrinsic pathway?
7, TNF (tissue factor; 3)
What are the factors in the common pathway?
1 (fibrinogen), 2, 5, 10
Which pathway is slow and which is fast?
Intrinsic is slow
Extrinsic is fast
What occurs when to cogaulation cascade enters the common pathway?
Thrombin is released altering fibrinogen to fibrin
How is the intrinsic pathway activated? What happens after it is active?
Activated when factor 12 binds to a neg charged foreign surface
Activates 11, 9, 8, 10, 2 I in the order) and fibrinogen is converted to fibrin
Which intrinsic factors are related to bleeding disorders?
8, 9, 11
How is the extrinsic pathway activated what what occurs once active?
TF at the site of injury activates it
TF complexes with 7 to form TF/7 (7a) which activates 10 and 9
9 activates more than 10 which activates 2 to form thrombin
What is the extrinsic pathway shut down by?
TFPI
If you have a deficiency in von Willebrand factor what occurs?
von Willebrand disease, a clotting disorder
What is thrombine time (TT)?
Citrated plasma + thrombin = hear end product clot
What is reptilase time?
Modification of TT where heparin inhibits via AT-3
Reptilase can still cleave fibrinogen in presence of heparin
Thrombin
Serine protease Cleaves fibrinogen to fibrin Activates V to Va, VIII to VIIIa Activates platelets-cleaves thrombin receptors Activates XIII to XIIIa
In the presence of what does thrombin activate protein C to APC?
Thrombomodulin
What does prothrombin time (PT) measure?
The clotting time of the EP; from factor 7 through fibrin
General measure EP and CP
What is the PTT?
Clotting time from 12 through fibrin formation (include 8, 9, 10, 5)
General measure of the IP and CP
What occurs if you have an inc in PTT but normal PT?
IP deficiencies
VIII, XI, XI, lupus anticoagulant
What occurs if PTT is normal but PT is inc?
EP deficiencies
Liver disease, VII, mild to moderate II, V, X deficiency
What occurs if both PTT and PT are inc?
Common pathway deficienies
vWD, liver disease II, V, X or multiple
What occurs if PTT and PT are normal?
Dec PTL function, deficiency in XIII, mild deficiency in other factors, mild vWD
(this is from an external wound)
