Which of the following is
the anticoagulant of choice for most coagulation studies?
C. Sodium citrate 3.2%
Which ratio of anticoagulant to blood is correct for coagulation procedures
1:9
Which results would be expected
for the prothrombin time (PT) and activated partial thromboplastin time (APTT)
in a newborn with a hematocrit of 65%?
a. Both prolonged
b. Both shortened
c. Normal PT, prolonged APTT
d. Both normal
What reagents are used in
the PT test?
Thromboplastin
Calcium chloride
Which tests will be
abnormal in a patient with Stuart-Prower factor deficiency?
D. Two of the above
The following factors are
measured by either the PT or APTT except:
A. Factor XIII
A modification of which
procedure can be used to measure fibrinogen?
C. Thrombin time
All of the following are characteristics
of vitamin K except:
D. It’s activity is enhanced by heparin therapy
Which statement about the
fibrin degradation product test is false?
C. Detects only degradation products from a stable fibrin clot
In a vitamin K deficient
patient, which of the following coagulation tests will be abnormal?
A. PT and APTT
Which of the following is
incorrect regarding the international normalized ratio (INR)?
B. Standardizes APTT results
Which of the following is
required for the endogenous activation of plasminogen?
A. Tissue plasminogen factor
Which of the following is a primary inhibitor of the fibrinolytic system?
B. α2-antiplasmin
All of the following are characteristics of thrombotic thrombocytopenic purpura except:
B. Renal dysfunction
All of the following physiological conditions may be associated with thrombocytopenia except:
C. Increased production of pluripotential stem cells
Aspirin prevents platelet aggregation by inhibiting the action of which enzyme?
A. Cyclooxygenase
Which of the following factors is essential for normal platelet adhesion?
A. Glycoprotein Ib
Which of the following test result(s) is (are) normal in a patient with classic von Willebrand's disease?
B. Platelet count
All of the following laboratory results support the diagnosis of von Willebrand's disease except:
B. Normal platelet aggregation to ristocetin
When performing platelet aggregation studies, which platelet aggregation responses would most likely
occur in a patient with Bernard-Soulier syndrome?
A. Normal platelet aggregation to collagen, ADP, and epinephrine, decreased aggregation to ristocetin
Which of the following is characteristic of acute idiopathic thrombocytopenic purpura?
A. Found predominantly in adults
TTP is different from DIC in that:
B. APTT is normal in TTP but prolonged in DIC
The APTT is sensitive to deficiency of:
D. Factor VII
A patient with a prolonged PT is given intravenous vitamin K. After 24 hours the PT corrects to normal. What clinical condition most likely caused these results?
A. Obstructive jaundice
All of the following are characteristics of classic hemophilia A except:
D. Decreased vWF:Ag
In DIC, which test result is unlikely?
A. Decreased APTT
Which of the following is a predisposing condition for the development of DIC?
D. All of the above
Factor XII deficiency is associated with:
C. Increased risk of thrombosis
The following results were obtained on a patient:
Prolonged bleeding time, normal platelet count, normal PT, prolonged APTT. Which of the following disorders is most consistent with these results?
B. Von Willebrand's disease
The following lab results have been obtained from a 40 year old woman: PT= 20 seconds↑, APTT = 50 seconds↑, Thrombin Time = 18 seconds↑. What is the
most probable diagnosis?
D. Hypofibrinogenemia
Christmas factor is the synonym for factor:
D. IX
Following aspirin ingestion, coagulation tests should be postponed for:
B. 1 week
A patient with a deficiency of factor XIII usually presents with a(n):
D. Normal PT and APTT
A patient's plasma produces an elevated PT and APTT and does not produce a normal PT and APTT when mixed with normal plasma: The most likely cause is:
D. Factor inhibitors
Heparin:
B. Binds with ATIII to inhibit thrombin
A qualitative platelet defect will affect the:
B. Bleeding time
An autosomal dominant inheritance, easy bruising, and a prolonged bleeding time are consistent with:
B. Von Willebrand's factor
All of the following are characteristics of Antithrombin III except:
C. It is a pathologic inhibitor of coagulation
All of the following tests are affected by heparin therapy except:
A. Reptilase time
The lupus anticoagulant is directed against:
A. Phospholipid
All of the following statements regarding warfarin (Coumadin) are true except:
C. It needs antithrombin as a cofactor
All of the following are characteristics of protein C except:
D. Its activity is inhibited by protein S
Which of the following is most commonly associated with activated protein C resistance?
D. Thrombosis
A 50 year old woman develops signs and symptoms of thrombosis in her left lower leg following 3 days of heparin therapy. The patient had open heart surgery 3 days ago and has been on heparin since. Which of the following would be the most useful to investigate the cause of her thrombosis?
A. Monitor the platelet count
The following lab results were obtained on a 25 year old woman with menorrhagia after delivery of her second son. The patient has no previous bleeding history.
Normal platelet count, normal bleeding time, normal PT, prolonged APTT
Mixing of the patient's plasma with normal plasma corrected the prolonged APTT upon immediate testing. However, mixing followed by a 2-hour incubation at 37oC caused a prolonged APTT. What is the most probable cause of these laboratory results?
a. Lupus anticoagulant
b. Factor VIII deficiency
c. Factor IX deficiency
d. Factor VIII inhibitor
d. Factor VIII inhibitor
A 50-year old white man has been on heparin for the past 7 days. Which combination of the following tests is expected to be abnormal?
C. APTT, TT
Which of the following is characteristic of platelet disorders?
B. Mucous membrane hemorrhages
Which of the following is characteristic of Bernard-Soulier syndrome?
