Deck 38: Hemorrhagic Disorders and Laboratory Assessment

Question 1

A 21-year-old woman has a primary complaint of menorrhagia.Her coagulation screen gives the following results.
$\begin{array}{lll}\underline { \text { Test }}&\underline { \text { Test Result }}& \underline { \text { Reference range }}\\\text { Prothrombin time (PT) } & 12.0 \text { seconds } & 11-15 \text { seconds } \\\text { Partial thromboplastin time (PTT) } & 40 \text { seconds } & 25-37 \text { seconds } \\\text { Factor VII activity } & 35 \% & 50 \%-150 \% \\\text { Platelet count } & 275 \times {10}^{9} / \mathrm{L} & 150-400 \times {10}^{9} / \mathrm{L} .\end{array}$
What disorder is most likely?

A)hemophilia A
B)hemophilia B
C)VWD, type 1
D)factor X deficiency

Answer 1

VWD, type 1

Question 2

What are the primary roles of VWF?

A)mediates platelet adhesion and carrier molecule for factor VIII
B)mediates platelet aggregation and carrier molecule for factor IX
C)inhibits excess coagulation and activates protein C
D)activates plasmin and enhances vitamin K factors

Answer 2

mediates platelet adhesion and carrier molecule for factor VIII

Question 3

Which of the following tests is increased in a patient with severe hemophilia A?

A)PTT
B)thrombin time (TT)
C)PT
D)factor VIII assay

Answer 3

PTT

Question 4

Which of the following single-factor inherited deficiencies is most common as the cause for hemophilia?

A)factor V
B)factor VIII
C)factor IX
D)factor XI

Question 5

What is the typical clinical picture in patients with severe hemophilia A?

A)generalized bleeding after trauma or dental work
B)generalized hemorrhage
C)major bruising on extremities and chronic nosebleeds
D)serious anatomic bleeds into joints

Question 6

What is or are the possible mechanism (or mechanisms)for bleeding in patients with severe liver disease?

A)thrombocytopenia
B)inadequate production of procoagulants
C)disseminated intravascular coagulation (DIC)
D)all of the above

Question 7

Which of the following would be appropriate initial testing for the siblings in Question 1?

A)fibrinogen, D-dimer, and platelet aggregation studies
B)factor VIII assay, liver function tests, and vitamin K level
C)von Willebrand factor (VWF) antigen, Bethesda titer, and reptilase time
D)prothrombin time (PT), partial thromboplastin time (PTT), and platelet count

Question 8

Which of the following is decreased in DIC?

A)fibrinogen
B)PT
C)PTT
D)fibrin degradation products

Question 9

Clot-based mixing studies and Bethesda titers are used to test for

A)vitamin K deficiency
B)inhibitors (antibodies) against coagulation factors
C)DIC
D)hemophilia

Question 10

What is the purest form of factor VIII that is available for treating a bleeding patient with hemophilia A?

A)cryoprecipitate
B)recombinant factor VIII concentrate
C)fresh frozen plasma
D)factor VIII concentrate prepared by chemical concentration

Question 11

What coagulation screening test is the most sensitive for detecting mild liver disease?

A)fibrinogen
B)PTT
C)PT
D)TT

Question 12

In what is a patient with the following coagulation test results most likely deficient?
$\begin{array}{lll}\underline { \text { Test }}&\underline { \text { Test Result }}& \underline { \text { Reference range }}\\\text { Prothrombin time (PT) } & 17 \text { seconds } & 11-15 \text { seconds } \\\text { Partial thromboplastin time (PTT) } & 31 \text { seconds } & 25-37 \text { seconds } \\\text { Thrombin time (TT) } & 16 \text { seconds } & 15-21 \text { seconds }\end{array}$

A)fibrinogen
B)factor VII
C)factor VIII
D)factor X

Question 13

Which is the most common form of von Willebrand disease (VWD)?

A)type 1
B)type 2A
C)type 3
D)acquired

Question 14

Desmopressin acetate (DDAVP)is used to treat

A)dysfibrinogenemia
B)warfarin overdose
C)vitamin K deficiency
D)VWD, type 1

Question 15

What is the best test to distinguish hemophilia A from B or C?

A)specific factor assays
B)PTT
C)TT
D)bleeding time

Question 16

What test is useful for detection of a female carrier of hemophilia A?

A)PTT
B)PT
C)Factor VIII to VWF ratio
D)VWF antigen test

Question 17

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?

A)localized, acquired, anatomic
B)localized, congenital, anatomic
C)generalized, congenital, systemic
D)generalized, acquired, systemic

Question 18

The urea solubility test is used to detect deficiencies in which factor?

A)fibrinogen
B)factor V
C)factor XII
D)factor XIII

Question 19

The bleeding associated with renal disease is related most to defective

A)blood vessels.
B)plasma procoagulants.
C)platelets.
D)inhibitors.

Question 20

Which patient group is most susceptible to bleeding because of a deficiency of vitamin K-dependent proteins?

A)those with poor diets
B)those on antibiotic agents
C)pregnant women
D)newborns

Question 21

What procedure is used to quantitate a factor VIII inhibitor?

A)Bethesda assay
B)reptilase time
C)factor VIII concentration
D)VWF assay

Question 22

A 67-year-old woman arrives at the emergency department with acute bleeding into the back of the throat.A coagulation screen is ordered with the following results:
$\begin{array}{lll}\underline { \text { Test }}&\underline { \text { Result }}& \underline { \text { Reference range }}& \underline { \text { 1:1 Mix with }}\\&&& \underline { \text { Normal Plasma }}\\\text { Prothrombin time (PT) } & 12 \text { seconds } & 11-15 \text { seconds } \\\text { Partial thromboplastin time } & 57 \text { seconds } & 25-37 \text { seconds } &36 \mathrm{~seconds}\\\text { (PTT) }&&&\text { (immediate) } \\\text { Fibrinogen }& 450 \mathrm{mg} / \mathrm{dL} & 150-400 \mathrm{mg} / \mathrm{dL}\end{array}$
What would be a reasonable next step to perform?

A)Perform factor IX assay.
B)Perform factor VII assay.
C)Incubate the 1:1 mix at 37° C for 1 hour and then repeat the PTT.
D)Perform TT.

Question 23

Which type of VWD gives a positive response to low-dose ristocetin-induced platelet aggregation?

A)1
B)2A
C)2B
D)2N

Question 24

Which of the following screening tests would be normal when the plasma for the patient in Question 26 is analyzed?

A)PT
B)PTT
C)TT
D)all of the above

Question 25

Which of the following proteins is the best test to distinguish moderate to severe liver disease from vitamin K deficiency?

A)factor V concentration
B)factor VII concentration
C)factor VIII concentration
D)factor IX concentration

Question 26

All of the following can mask a deficiency of VWF and thus of type 1 VWD except

A)fibrinogen levels
B)pregnancy
C)acute stress
D)type AB blood group

Question 27

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?

A)factor VIII
B)factor IX
C)factor V
D)factor XIII