Hemostasis Flashcards
Maintains blood in a fluid, clot free state in normal vessels. Induces the formation of a hemostatic plug at the site of vascular injury
normal hemostasis
What would be the risk category of a surgery that involves non-vital organs and has a limited degree of surgical dissection?
low risk
What are the three examples from the lecture of low risk surgeries?
lymph node biopsy, herniorrhaphy, dental extractions
What are the four phases of hemostasis?
vascular, platelet, coagulation, fibrinolytic
During what phase of hemostasis does an injured blood vessel constrict?
vascular
At what point is the coagulation phase complete?
conversion of fibrinogen to fibrin
What factors require vitamin K for activation?
VII, IX, X, prothrombin
Breaks down fibrin and fibrinogen into degradation products
plasmin
Enzymes responsible for the activation of plasminogen to plasmin in the extrinsic pathway
t-PA and urokinase
Enzymes responsible for the activation of plasminogen to plasmin in the intrinsic pathway
factor XIIa, HMWK, kallikrein
Enzyme responsible for the activation of plasminogen to plasmin exogneously
streptokinase
What cells are responsible for synthesizing and secreting von Willebrand factor (factor VIII)?
endothelial
Provides assessment of platelet count and function. Normal value is 2-8 minutes
bleeding time
Measures effectiveness of the extrinsic pathway. Normal is 10-15 secs
prothrombin time (PT)
Measures effectiveness of the intrinsic pathway. Normal is 25-40 secs
partial thromboplastin time (PTT)
Measures time for thrombin to convert fibrinogen to fibrin. Normal value is 9-13 secs
thrombin time
What is the best way of evaluating unsuspected bleeder after an H&P?
Peripheral Blood smear…thrombocytopenia
Most common cause of bleeding disorders
vessel defects
Common causes of thrombocytopenia
bone marrow failure, hypersplenism, ETOH, thiazide diuretics
What is hypersplenism associated with in patients with cirrhosis?
portal hyptertension
How does liver disease alter hemostasis?
malabsorption of vitamin K reduces production of coagulation factors
Required for vitamin K absorption. Various intestinal diseases interfere with its metabolism and ultimately vitamin K dependent coagulation factors
bile acid
Name the five drugs or drug classes mentioned in lecture that interfere with hemostasis
ASA, anticoagulants, abx, ETOH, anticancer
Type of bleeding pattern that does not blanch with pressure
petechiae
Most common clinical manifestation of hemophila
hemarthrosis
Symptoms of this bleeding disorder include: easy bruising, epistaxis, gingival bleeding, menorrhagia, post-partum hemorrhage, and bleeding post-dental extraction
von Willebrands
Bleeding disorder that results from antiplatelet antibodies destroying platelets due to heparin administration
heparin induced thrombocytopenia (HIT)
Always the initial even of disseminated intravascular coagulation
coagulation
Laboratory results for this coagulation disorder include plt < 100,000, prolonged PT/PTT, positive D-dimer, and low levels of coagulation factors or inhibitors
DIC
