Deck 33: Disorders of Primary Hemostasis

Question 1

Scurvy can lead to vascular defects by which of the following mechanisms?

A)Degeneration of ECM
B)Excessive breakdown of collagen
C)Insufficient collagen synthesis
D)Presence of paraproteins directed against collagen

Answer 1

Insufficient collagen synthesis

Question 2

Which of the following best describes the effect of aspirin on platelets,and for how long does the effect last?

A)ADP receptor blockade;5 days
B)Thrombocytosis;7 days
C)Inactivation of cyclooxygenase;7 days
D)Thrombocytopenia;7 days

Answer 2

Inactivation of cyclooxygenase;7 days

Question 3

A patient is experiencing pinpoint petechial bruising on her upper torso.Her history revealed frequent nosebleeds during her childhood.Clot-based screening assays are within normal reference ranges,and platelet function assays are abnormal.Based on this information,what appears to be defective in this patient?

A)Coagulation factors
B)Platelets
C)The vasculature
D)Fibrinolytic system

Answer 3

Platelets

Question 4

All of the following are conditions associated with reactive thrombocytosis except:

A)Acute hemorrhage
B)Postsplenectomy
C)Chronic idiopathic myelofibrosis
D)Iron deficiency anemia

Question 5

An instrument report has a platelet count of 850 x 10⁹/L.This would be interpreted as:

A)Normal platelet count
B)Thrombocytosis
C)Thrombocytopenia
D)Cannot be interpreted

Question 6

Which hemostatic disorder usually is represented by a decreased platelet count,normal PT,normal APTT,and abnormal bleeding time?

A)Thrombocytosis
B)Thrombocytopenia
C)Vascular disorder
D)Platelet dysfunction

Question 7

Acquired disorders of the vascular system including senile purpura,Cushing's syndrome,corticosteroid therapy,and scurvy have one condition in common.Which of the following best describes this condition?

A)Decreased amount of supportive connective tissue in the blood vessel walls
B)Presence of abnormal proteins in the vascular system
C)Inflammation of the small blood vessels
D)Increased pressure within the lumen of capillaries after intense exercise

Question 8

Which of the following is not a mechanism of inducing thrombocytopenia in a patient?

A)Antibody-mediated platelet destruction
B)Inherited platelet membrane defect
C)Increased splenic sequestration
D)Inherited defect in release of ADP and ATP

Question 9

Which of the following physical symptoms are associated with scurvy?

A)Hemangiomas
B)Ecchymoses
C)Bleeding into joints and muscles
D)Purpura fulminans

Question 10

A patient has a splitting headache prior to his blood draw.He takes two aspirin,and his blood is drawn.Platelet aggregation studies are performed,and one comes back abnormal.Based on this information,which agonist will show a normal aggregation pattern?

A)Arachidonic acid
B)Epinephrine
C)Collagen
D)Ristocetin

Question 11

A 35-year-old female is hospitalized for knee replacement surgery.Preoperative blood tests reveal a platelet count of 64 x 10⁹/L.The surgery is postponed,and the platelet count is repeated two days later when it is 48 x 10⁹/L.All other labs appear normal.Based on this information,from what is the patient most likely suffering?

A)Acute ITP
B)Chronic ITP
C)TTP
D)HUS

Question 12

Minimum screening test(s)that should be considered in the evaluation of abnormal bleeding is(are)which of the following?

A)Thrombin time
B)Fibrinogen level
C)Factor studies
D)Platelet count,PT,APTT

Question 13

A patient is exhibiting multiple pinpoint hemorrhages on his upper torso.This would be described as:

A)Hematomas
B)Ecchymoses
C)Purpura
D)Petechiae

Question 14

Increased risk of bleeding into the central nervous system occurs with a platelet count of:

A)800 x 10⁹/L
B)200 x 10⁹/L
C)150 x 10⁹/L
D)30 x 10⁹/L

Question 15

A patient visits a physician because of unexplained bruising and prolonged bleeding from a recent tooth extraction.The physician orders a prothrombin time (PT)and an APTT.Results are within normal reference ranges.What other tests could the physician order to investigate the patient's symptoms?

A)Platelet count and platelet function assays
B)Platelet function assays
C)Platelet count only
D)Repetition of the PT and the APTT after the beginning of treatment

Question 16

What is the condition when petechiae and ecchymoses are found in a higher-than-normal number with less-than-usual trauma?

A)Hematoma
B)Purpura
C)Easy bruisability
D)Excess bleeding

Question 17

A patient has a platelet count of 80 x 10⁹/L and a bleeding time of 15 minutes.From what is the patient most likely suffering?

A)A platelet function disorder
B)A quantitative platelet disorder
C)A combined platelet disorder
D)von Willebrand disease
Question: Is it good practice to perform a bleeding time on a thrombocytopenic patient? No.Also Bleeding Times are being replaced in many labs by TEG (thromboelastography)and platelet function analyzers (i.e.PFA 100)

Question 18

A patient's peripheral blood smear reveals many giant platelets.All platelet function tests show normal aggregation with the exception of ristocetin.From what is the patient most likely suffering?

A)Glanzmann's thrombasthenia
B)Bernard-Soulier syndrome
C)Storage pool disease
D)Wiskott-Aldrich syndrome

Question 19

Predict the typical expected results of clot-based PT in a patient with a platelet defect.

A)Prolonged
B)Normal
C)Shortened
D)Cannot be predicted

Question 20

Thrombocytosis is associated with which of the following?

A)Acute leukemia
B)ITP
C)HUS
D)Myeloproliferative disorder

Question 21

Immune complexes induce vasculitis by which of the following processes?

A)Inducing aggregation of platelets and activation factor XII
B)Increasing pressure within the lumen of capillaries
C)Forming thrombi in the small vessels,inducing necrosis
D)Releasing enzymes and free oxygen radicals from neutrophils that have migrated to the area to phagocytize the immune complexes

Question 22

What would be the expected laboratory results in a patient with thrombocytopenia?

A)Platelet counts <50 × 10⁹/L
B)Normal bleeding time
C)Abnormally prolonged PT and APTT
D)Decreased fibrinogen

Question 23

Which of the following characteristics of chronic ITP differentiates it from acute ITP?

A)Platelet count of < 20 × 10⁹/L
B)Gender predilection in females of 3:1
C)Duration of 2-6 weeks
D)Lymphocytosis

Question 24

What laboratory tests are used to assess disorders of primary hemostasis and secondary hemostasis?

Question 25

Give at least five markers of differentiation between acute and chronic ITP.

Question 26

Describe the following,and indicate whether they are typically seen in disorders of primary or secondary hemostasis.
a.Petechiae
b.Purpura
c.Ecchymoses
d.Hematomas

Question 27

How do hematologic disorders contribute to the pathogenesis of thrombocytopenia?

Question 28

Explain the pathophysiology of the following and why each typically has normal coagulation screening tests.
a.Bernard-Soulier syndrome
b.Glanzmann's thrombasthenia
c.-storage pool disease
d.Gray platelet syndrome

Question 29

What is the most common cause of thrombocytopenia?

A)Increased consumption
B)Increased destruction
C)Decreased production
D)Increased splenic sequestration

Question 30

A patient has a splitting headache shortly before getting her blood tested.She takes a couple of aspirin and is scheduled for platelet aggregation studies.What effect will this have on the platelet aggregation studies?

A)Platelets will show diminished activity with selected agonists.
B)Platelets will show normal activity with all agonists.
C)Platelets will show increased activity with selected agonists.
D)Platelets will show variable activity with all agonists.

Question 31

Aspirin affects platelet aggregation because it interferes with:

A)Cyclooxygenase activity
B)Platelet adhesion to collagen
C)Development of platelets
D)Binding of fibrinogen to platelets

Question 32

A patient is known to be a chronic alcoholic.His blood is drawn,and his platelet count is 72 x 10⁹/L.What is the most likely reason for this occurrence?

A)Immune-mediated thrombocytopenia
B)Acquired hypoplasia resulting from alcohol consumption
C)Dilutional thrombocytopenia from liver dysfunction
D)Increased destruction of platelets

Question 33

Splenomegaly can cause thrombocytopenia by which of the following mechanisms?

A)Impaired production
B)Platelet sequestration
C)Immune-mediated
D)Mechanical destruction

Question 34

Which of the following contributes to the pathogenesis of Bernard-Soulier syndrome?

A)Abnormal glycoprotein Ib/IX complex
B)Abnormal glycoprotein IIb/IIIa
C)High platelet count
D)Low fibrinogen level

Question 35

What is a common etiology of ITP in children?

A)Tooth extraction
B)Easy bruising syndrome
C)Vasculitis
D)Chickenpox