2.5 Hemostasis Problem Solving

Question 1

A 3-year-old male was admitted 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.

These clinical manifestations and laboratory results are consistent with which condition?

Answer 1

ITP

Question 2

A 12-year-old white male has the following symptoms: visible bruising on arms and
legs, bruising after sports activities, and excessive postoperative hemorrhage after
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.

These clinical manifestations and laboratory results are consistent with which diagnosis?

Answer 2

von Willebrand disease

Question 3

The following results are obtained from a patient who developed severe bleeding:

Prolonged PT and APTT
PLT count = 100 × 109/L
Fibrinogen = 40 mg/dL

Which of the following blood products should be recommended for transfusion?

Answer 3

Cryoprecipitate

Question 4

A 30-year-old woman develops signs and symptoms of thrombosis in her left lower leg after 5 days of heparin therapy. The patient had had open-heart surgery 3 days previously and has been on heparin ever since. Which of the following would be most helpful in making the diagnosis?

Answer 4

PLT count

Question 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 PLT count; 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 prolonged APTT.

What is the most probable cause of these laboratory results?

Answer 5

Factor VIII inhibitor

Question 6

A 62-year-old female presents with jaundice and the following laboratory data:

• Peripheral blood smear = macrocytosis, target cells
• PLT count = 355 × 109/L
• PT = 25 sec (reference range = 10–14)
• APTT = 65 sec (reference range = 28–36)
  -Transaminases = elevated (AST:ALT ratio greater than 1)
  -Total and direct bilirubin = elevated

These clinical presentations and laboratory results are consistent with:

Answer 6

Cirrhosis of the liver

Question 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?

Answer 7

The laboratory protocol should be followed for the interpretation of correction

Question 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 was not on heparin therapy. Which is the most appropriate first step to investigate the abnormal results?

Answer 8

Check the sample for a clot

Question 9

A plasma sample submitted to the laboratory for PT testing has been stored for 25 hours at 4°C. PT is shortened. What is the most probable cause?

Answer 9

Activation of factor VII caused by exposure to cold temperature

Question 10

APTT is not increased in a patient receiving heparin. Which of the following factors may be associated with the lack of response to heparin therapy in this patient?

Answer 10

AT deficiency

Question 11

A 50-year-old patient was admitted to the emergency department with a complaint of pain in the right leg. The leg was red, swollen, and warm to the touch. DVT was suspected, and the patient was started on heparin therapy. Which of the following is (are) the proper protocol(s) to evaluate patients receiving heparin therapy?

Answer 11

Baseline APTT and PLT count; APTT testing every 4 to 6 hours after the initial heparin bolus

Question 12

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

Answer 12

TTP

Question 13

A 1-year-old infant was admitted with recurrent epistaxis for the past 5 days. Past medical history revealed easy bruising and a severe nosebleed that had occurred when he was 3 months of age, necessitating transfusion therapy. The mother had a severe nosebleed 8 years ago. The father was reported to bleed easily after lacerations. The patient was transfused with 2 units of packed RBCs on admission.

These clinical manifestations and laboratory results are consistent with which condition?

Answer 13

Glanzmann thrombasthenia

Question 14

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:

Answer 14

Lupus anticoagulant

Question 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 obtained at the time of admission revealed prolonged PT with an INR of 4.5. What is the physician’s most appropriate course of action?

Answer 15

Cancel the procedure and start the patient on vitamin K therapy

Question 16

A fresh blood sample was sent to the laboratory at 8:00 a.m. for the PT test. At 4:00 p.m., the doctor requested for the APTT test to be done on the same sample. What should the technologist do?

Answer 16

Request a new sample for APTT

Question 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 because of failure of the delta check. The patient had 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?

Answer 17

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

Question 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 HIT and ordered the PLT aggregation test to be performed immediately. The heparininduced PLT 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?

Answer 18

The negative PLT aggregation does not rule out HIT

Question 19

A 50-year-old female was admitted to a hospital for hip replacement surgery. Preoperative tests were performed, and the results showed the following:

Hgb = 13.5 g/dL
Hct = 42%
PT = 12 sec
APTT = 36 sec.

The patient was bleeding during surgery, and postoperative test results revealed the following:

Hgb = 5.0 g/dL
Hct = 16%
PT = 8 sec
APTT = 25 sec.

What steps should be taken before releasing these results?

Answer 19

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

Question 20

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 child birth several years earlier or during a tonsillectomy in childhood. Her family history was unremarkable.

These clinical manifestations and laboratory results are consistent with:

Answer 20

Factor V inhibitor