Chapters 37 and 38
In what is a patient with the following coagulation test results most likely deficient? PT: 17 sec (11-15 sec) PTT: 31 sec (25-37 sec) TT: 16 sec (15-21 sec)
Factor VII
Which of the single-factor inherited deficiencies is most common as the cause for hemophilia?
Factor VIII
What test is useful for detection of a female carrier of hemophilia A?
Factor VIII to vWF ratio
The urea solubility test is used to detect deficiencies on which factor?
Factor XIII
A 67 year old woman arrives at the ER with acute bleeding into the back of the throat. A coagulation screen is ordered with the following results: PT: 12 sec (11-15 sec) PTT: 57 sec (25-37 sec) Fibrinogen: 450 mg/dL (150-400 mg/dL) What would be a reasonable next step to perform?
Incubate the 1:1 mix at 37C for 1 hour and then repeat the PTT
What coagulation screening test is the most sensitive for detecting mild liver disease?
PT
Which of the following is decreased in acute DIC? - fibrinogen - PT - PTT - fibrin degradation products
PTT
Which of the following tests is increased in a patient with severe hemophilia A? - PTT - TT - PT - factor VIII assay
PTT
Which test will detect dysfibrinogenemia?
Reptilase Time
Which of the following therapies actually lyses the clot rather than prevents future clots? - aspirin - heparin - TPA - coumadin
TPA
Which of the following are components of the contact group of factors? - fibrinogen and thrombin - VIII and vWF - XII and prekallikrein - calcium of IX
XII and prekallikrein
All of the following are functions of thrombin EXCEPT: - activates factors V and VIII - activates plasminogen - activated factor XIII - initiates platelet adhesion
activates plasminogen
What is the role of the thrombin-thrombomodulin complex?
activates protein C
What is or are the possible mechanism(s) for bleeding in patients with severe liver disease? - thrombocytopenia - inadequate production of procoagulants - disseminated intravascular coagulation (DIC) - all of the above
all of the above
What protein does heparin work with to inhibit coagulation?
antithrombin
What substance is known to inactivate cyclooxygenase, causing impairment of platelet function?
aspirin
What is the role cofactors play in the procoagulant process?
bind to their specific activated serine pretease to stabilize to protease and increase its activity
Which of the following is part of primary hemostasis? - fibrinolysis - blood vessels - intrinsic system - inhibitors
blood vessels
Absence of D-dimers is useful for ruling out
deep vein thrombosis (DVT)
Which of the following proteins is the best test to distinguish moderate to severe liver disease from vitamin K deficiency? - factor V concentration - factor VII concentration - factor VIII concentration - factor IX concentration
factor V concentration
A 39 year old male patient shows evidence of poor wound healing and a history of joint bleeding. What protein deficiency is most likely present?
factor XIII screening tests that would be normal (plasma): PT, PTT, TT
What plasma protein is important for normal wound healing and stabilization of the fibrin clot?
factor XIIIa
Which of the following is necessary for platelet aggregation? - protein S - kallikrein - vitamin K - fibrinogen
fibrinogen
Two children in the same family have recurrent, chronic bruising in multiple sites, repeated long-lasting epistaxis, and minor bleeding after dental work. Which type of disorder is most likely?
generalized, congenital, systemic initial testing ( PT, PTT, and platelet count)
Clot based mixing studies and Bethesda titers are used to test for
inhibitors (antibodies) against coagulation factors
Where are most of the plasma procoagulant proteins produced?
liver
What are the primary roles of vWF?
mediates platelet adhesion and carrier molecule for factor VIII
What substance digests the fibrin clot after healing?
plasmin
Which of the following aids in preventing excess clotting? - thrombin - factor VII - nitric oxide - protein C
protein C
What is the purest form of factor VIII that is available for treating a bleeding patient with hemophilia A?
recombinant factor VIII concentrate
Patients who have a deficiency of protein C or protein S have which type of disorder?
thrombotic disorder
What is the most common form of von Willebrand disease (vWD)?
type 1
A 21 year old woman has a primary complaint of menorrhagia. Her coagulation screen gives the following results: PT: 12.0 sec (11-15 sec) PTT: 40 sec (25-37 sec) Factor VIII activity: 35% (50-150%) Platelet count: 225 (150-400) What disorder is most likely?
vWD, type 1
Desmopressin acetate (DDAVP) is used to treat?
vWD, type 1
On what does factor VIII depend for stability?
vWF
Which of the following is necessary for platelet adhesion to collagen? - calcium - fibrinogen - vWF - factor XIII
vWF
What vitamin is essential for normal synthesis of prothrombin group proteins, thus enabling the to bind Ca2+?
vitamin K
Common treatment with oral anticoagulation is based on
vitamin K antagonism
