Hematology- Hemostasis Problem Solving

Question 1

1. Patient History
   A 3-year-old male was admitted to a hospital with
   scattered petechiae and epistaxis. The patient had
   normal growth and had no other medical problems
   except for chickenpox 3 weeks earlier. His family
   history was unremarkable.

Laboratory Results
PT: 11 sec (Ref.range: 10–13 sec)
APTT: 32 sec (Ref.range: 28–37 sec)
Platelet count: 18 × 103/μL (Ref.range: 150–450 × 103/μL)

These clinical manifestations and laboratory results
are consistent with which condition?
A. TTP
B. DIC
C. ITP
D. HUS

Answer 1

C. ITP

Question 2

2. Patient History
   A 12-year-old white male has the following
   symptoms: visible bruising on arms and legs,
   bruising after sports activities, and excessive
   postoperative hemorrhage following tonsillectomy
   3 months ago. His family history revealed that
   his mother suffers from heavy menstrual bleeding,
   and his maternal grandfather had recurrent
   nosebleeds and bruising

Lab results :
Platelet Count: 350 × 103/μL (Range: 200–450 × 103/μL)

PT: 11.0 sec (Range:10–12 sec)
APTT: 70 sec (Range:28–37 sec)
TT: 13 sec (Range:10–15 sec)

Platelet Aggregation:
Normal aggregation
with collagen,
epinephrine, ADP

Abnormal
aggregation
with ristocetin

Confirmatory
VWF:Rco 25% (Range: 45%–140%)

VIII:C 20% (Range: 50%–150%)

WWF:antigen 10% (Range:45%–185%)

These clinical manifestations and laboratory results
are consistent with which diagnosis?
A. Factor VIII deficiency
B. von Willebrand’s disease
C. Glanzmann’s thrombasthenia
D. Bernard–Soulier syndrome

Answer 2

B. von Willebrand’s disease

Question 3

3. The following results are obtained from a patient
   who developed severe bleeding:
   Prolonged PT and APTT
   Platelet count = 100 × 109 /L
   Fibrinogen = 40 mg/dL
   Which of the following blood products should be
   recommended for transfusion?
   A. Factor VIII concentrate
   B. Platelets
   C. Fresh frozen plasma
   D. Cryoprecipitate

Answer 3

D. Cryoprecipitate

Question 4

4. A 30-year-old woman develops signs and
   symptoms of thrombosis in her left lower leg
   following 5 days of heparin therapy. The patient
   had open-heart surgery 3 days previously and has
   been on heparin ever since. Which of the following
   would be the most helpful in making the
   diagnosis?
   A. Fibrinogen assay
   B. Prothrombin time
   C. Platelet counts
   D. Increased heparin dose

Answer 4

C. Platelet counts

Question 5

5. The following laboratory 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 on immediate
   testing. However, mixing followed by 2-hour
   incubation at 37°C 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

Answer 5

D. Factor VIII inhibitor

Question 6

6. A 62-year-old female presents with jaundice
   and the following laboratory data:
   Peripheral blood smear: macrocytosis, target cells
   Platelet count: 355 × 109/L
   PT: 25 sec (reference range =10–14)
   APTT: 65 sec (reference range = 28–36)
   Transaminases: elevated (AST:ALT>1)
   Total and direct bilirubin: elevated
   These clinical presentations and laboratory results
   are consistent with:

A. Inherited factor VII deficiency
B. DIC
C. Cirrhosis of the liver
D. von Willebrand’s disease

Answer 6

C. Cirrhosis of the liver

Question 7

7. When performing a mixing study, the patient’s
   APTT is corrected to 12% of normal. What is the
   most appropriate interpretation of these findings?
   A. The APTT is considered corrected
   B. The APTT is considered uncorrected
   C. The mixing study needs to be repeated
   D. A circulating anticoagulant can be ruled out

Answer 7

C. The mixing study needs to be repeated

Question 8

8. A standard blue-top tube filled appropriately (with
   4.5 mL blood) was submitted to the laboratory for
   preoperative PT and APTT testing. The results
   of both tests were elevated. The patient’s PT and
   APTT from the previous day were within normal
   limits, and he is not on heparin therapy. Which is
   the most appropriate first step to investigate the
   abnormal results?
   A. Report the result as obtained
   B. Perform a mixing study
   C. Check the sample for a clot
   D. Report the APTT only

Answer 8

C. Check the sample for a clot

Question 9

9. A plasma sample submitted to the lab for PT
   testing has been stored for 25 hours at 4°C.
   The PT result is shortened. What is the most
   probable cause?
   A. Factor VII deficiency
   B. Activation of factor VII due to exposure to cold
   temperature
   C. Lupus inhibitor
   D. Factor X inhibitor

Answer 9

B. Activation of factor VII due to exposure to cold
temperature

Question 10

10. The APTT results are not elevated in a patient
    receiving heparin. Which of the following factors
    may be associated with the lack of response to
    heparin therapy in this patient?
    A. Protein C deficiency
    B. Antithrombin deficiency
    C. Protein S deficiency
    D. Factor VIII deficiency

Answer 10

B. Antithrombin deficiency

Question 11

11. A 50-year-old patient was admitted to the
    emergency department complaining of pain in her
    right leg. Her leg was red, swollen, and warm to
    the touch. Deep venous thrombosis was suspected,
    and the patient was started on heparin therapy.
    Which of the following is (are) the proper protocol
    to evaluate patients receiving heparin therapy?
    A. A baseline APTT and platelet count; APTT
    testing every 6 hours until the target is reached
    B. Repeat APTT after 5 days postheparin therapy to
    adjust the therapeutic dose
    C. Monitor the platelet count daily and every other
    day after heparin therapy is completed
    D. Monitor PT daily to adjust the therapeutic dose

Answer 11

A. A baseline APTT and platelet count; APTT
testing every 6 hours until the target is reached

Question 12

12. Patient History:
    A 46-year-old female was admitted to the emergency
    department with complaints of headache, dizziness,
    lethargy, nausea, vomiting, and weakness. The
    patient had a gastrectomy procedure 4 months
    earlier to remove adenocarcinoma of the stomach.
    She was placed on mitomycin therapy. Diagnostic
    procedures indicated recurrence of the carcinoma.

These clinical manifestations and laboratory results
are consistent with:
A. ITP
B. von Willebrand’s disease
C. TTP
D. DIC

Answer 12

C. TTP

Question 13

13. Patient History
    A 1-year-old infant was admitted to the hospital
    with recurrent epistaxis for the past 5 days. The
    past medical history revealed easy bruising and a
    severe nosebleed at 3 months of age, necessitating
    transfusion therapy. The mother had had a severe
    nosebleed 8 years ago. The father was reported to
    bleed easily after lacerations. The patient was
    transfused

These clinical manifestations and laboratory results
are consistent with which condition?
A. von Willebrand’s disease
B. Bernard–Soulier syndrome
C. Glanzmann’s thrombasthenia
D. Factor VIII deficiency

Answer 13

C. Glanzmann’s thrombasthenia

Question 14

14. Patient History:
    A 30-year-old female was referred to the hospital
    for evaluation for multiple spontaneous abortions
    and current complaint of pain and swelling in her
    right leg. Her family history is unremarkable.

These clinical manifestations and laboratory results
are consistent with:
A. Factor VIII inhibitor
B. Factor VIII deficiency
C. Anticardiolipin antibodies
D. Lupus anticoagulant

Answer 14

D. Lupus anticoagulant

Question 15

15. A 60-year-old patient was admitted to a hospital
    for a liver biopsy. The biopsy was scheduled for
    11:00 a.m. The coagulation results performed at
    the time of admission revealed a prolonged PT
    with an INR of 4.5.

What is the physician’s most
appropriate course of action?
A. Proceed with biopsy, because a prolonged PT is
expected in liver disease
B. Postpone the procedure for a couple of days
C. Cancel the procedure and start the patient on
vitamin K therapy
D. Put patient on vitamin K and proceed with the
procedure immediately

Answer 15

C. Cancel the procedure and start the patient on
vitamin K therapy

Question 16

16. A fresh blood sample was sent to the laboratory at
    8:00 a.m. for a PT test. At 4:00 p.m., the doctor
    requested an APTT test to be done on the same
    sample. What should the technologist do?
    A. Rerun APTT on the 8:00 a.m. sample and report
    the result
    B. Request a new sample for APTT
    C. Run APTT in duplicate and report the average
    D. Mix the patient plasma with normal plasma and
    run the APTT

Answer 16

B. Request a new sample for APTT

Question 17

17. An APTT test is performed on a patient and the
    result is 50 sec (reference range 27–37 sec). The
    instrument flags the result owing to failure of the
    delta check. The patient had an APTT of 35 sec
    the previous day. The technologist calls the
    nursing unit to check whether the patient is on
    heparin therapy. The patient is not receiving
    heparin. What is the next appropriate step?
    A. Check the family history for an inherited factor
    VIII deficiency
    B. Check to see if the patient has received any other
    anticoagulant medications
    C. Perform mixing studies
    D. Perform a factor VIII assay

Answer 17

B. Check to see if the patient has received any other
anticoagulant medications

Question 18

18. A patient was put on heparin therapy
    postoperatively for prevention of thrombosis.
    The patient had the following laboratory results
    on admission: Platelet count = 350 × 109/L; PT =
    12 sec (reference: 10–13 sec); APTT = 35 sec
    (reference: 28–37). After 6 days of heparin
    therapy, the patient complained of pain and
    swelling in her left leg. Her platelet count dropped
    to 85 × 109/L and her APTT result was 36 sec.
    The physician suspected heparin-induced
    thrombocytopenia (HIT) and ordered a platelet
    aggregation test to be performed immediately.
    The heparin-induced platelet aggregation test
    result was negative. Heparin therapy was
    continued. Several days later, the patient
    developed a massive clot in her left leg that
    necessitated amputation.
    Which of the following should have been
    recognized or initiated?
    A. The patient should have been placed on LMWH
    B. The heparin dose should have been increased
    C. The negative platelet aggregation does not rule
    out HIT
    D. The patient should have been placed on warfarin
    therapy

Answer 18

C. The negative platelet aggregation does not rule
out HIT

Question 19

19. A 50-year-old female was admitted to a hospital
    for hip replacement surgery. The preoperative tests
    were performed and the results showed an Hgb
    of 13.5 g/dL; Hct = 42%; PT = 12 sec; APTT =
    36 sec. The patient was bleeding during surgery
    and the postoperative test results revealed an
    Hgb = 5.0 g/dL; Hct = 16%; PT = 8 sec; and
    APTT = 25 sec.
    What steps should be taken before releasing these
    results?
    A. No follow-up steps are needed; report the results
    as obtained
    B. Report Hgb and Hct results, adjust the
    anticoagulant volume, and redraw a new sample
    for PT and APTT
    C. Call the nurse and ask if the patient is receiving
    heparin
    D. Because the patient is severely anemic, multiply
    the PT and APTT results by two and report the
    results

Answer 19

B. Report Hgb and Hct results, adjust the
anticoagulant volume, and redraw a new sample
for PT and APTT

Question 20

20. Patient and Family History
    A 45-year-old woman visited her doctor
    complaining of easy bruising and menorrhagia
    occurring for the past few weeks. The patient had
    no history of excessive bleeding during childbirth
    several years earlier nor during a tonsillectomy in several years earlier nor during a tonsillectomy in
    childhood. Her family history was unremarkable.

These clinical manifestations and laboratory results
are consistent with:
A. Factor VIII inhibitor
B. Factor V inhibitor
C. Factor VIII deficiency
D. Lupus anticoagulant