Coagulation Exam Questions with Detailed Answers Already Passed
A 44-year-old man in acute distress is noted to have multiple ecchymoses of the skin that have
developed over the past 48 hours. His prothrombin time (PT) is 38 seconds and partial thromboplastin
time (PTT) 55 seconds. A CBC shows a WBC count of 5300/microliter, hemoglobin 8.1 g/dL, hematocrit
24.9%, MCV 99 fL, and platelet count 16,300/microliter. His D-Dimer test is very high. Which of the
following is the most likely diagnosis? - Answers DIC (Disseminated intravascular coagulopathy)
What does a positive D-Dimer mean? - Answers Generation of fibrin degradation products (widespread
activation of clotting)
What disease leads to prolonged bleeding or petechial hemorrhages? - Answers VWD (vonWillebrand
Disease)
A clinical study is performed with subjects who have thrombocytopenia <10,000/microliter. These
patients are observed to have defects in coagulation with spontaneous bleeding characterized by
multiple petechiae and purpura and stool samples positive for occult blood. What coagulation functions
is most likely to remain largely intact in these patients? - Answers Conversion of fibrinogen to fibrin
(driven by coagulation factor)
A 28-year-old woman has a history of easy bruising with minor trauma, frequent nosebleeds, and
menorrhagia. On examination purpuric areas are noted on her extremities. Laboratory studies show a
normal PT and normal PTT. Her Hgb is 12.8 g/dL, Hct 39.7%, MCV 91 fL, platelet count 88,500/microliter,
and WBC count 8160/microliter. Platelet function studies show that her platelets do not aggregate in
response to ristocetin. Which of the following deficiencies most likely explains her disease? - Answers
Glycoprotein Ib-IX (Bernard Soulier Syndrome)
A 35-year-old woman has noted small hemorrhages on her skin increasing in number over the past
month. On physical examination she has petechiae involving skin surfaces of her torso and extremities.
Laboratory studies show a normal PT and normal PTT. Her Hgb is 9.8 g/dL, Hct 29.4%, MCV 80 fL,
platelet count 276,300/microliter, and WBC count 7290/microliter. Platelet function studies are normal.
What the most likely diagnosis? - Answers Scurvy (capillary fragility)
A 12-year-old boy has had worsening problems with joint mobility involving his arms and legs,
particularly his knees and ankles, for the past 6 years. He has been receiving therapy for this condition.
On physical examination he has no visible petechiae or areas of purpura. Laboratory studies show that
his prothrombin time is 12 seconds and his partial thromboplastin time is 52 seconds. After addition of
an equivalent aliquot of normal plasma, his PTT is 40 seconds. His Hgb is 12.9 g/dL, platelet count
238,500/microliter, and WBC count 6620/microliter. What is the most appropriate statement regarding
his clinical condition? - Answers Transfusion of Factor VII is helpful (Hemophilia A)
A 69-year-old woman has had flank pain and a high fever for a week. On physical examination her
temperature is 38°C. There is left costovertebral angle tenderness. A urine culture is positive for
Escherichia coli. She then has a drop in blood pressure and in urine output. A blood culture grows
, Escherichia coli. Her prothrombin time is 34 seconds and her partial thromboplastin time 59 seconds.
Her platelet count is 11,000/microliter. Her D-dimer is elevated. Which of the following is the most likely
mechanism for development of her laboratory findings? - Answers Endothelial cell injury (DIC)
A clinical study is conducted comparing patients diagnosed with vonWillebrand disease (VWD) to
patients diagnosed with hemophilia A. Both groups of patients have documented problems of
hemostasis over a 10 year period. Which of the following complications is most likely to be seen more
frequently in the patients with hemophilia A? - Answers Bleeding in joints
This is caused by a deficiency in factor IX and leads to prolonged PTT - Answers Hemophilia B (coag.
factor deficiency)
A 30-year-old man experiences excessive bleeding following a wisdom tooth extraction. There is a family
history of similar problems. His mother had a history of menorrhagia. His sister has frequent nosebleeds.
Laboratory studies on this man show he has a normal PT, PTT, and platelet count. Which of the following
is the most likely diagnosis? - Answers VWD (Depending upon the type of mutation and severity of the
disease, the amount of bleeding can vary. Also, factor VIII levels may be affected and prolong the PTT in
some cases.)
A 38-year-old man has frequent nosebleeds that are difficult to stop. On physical examination there are
no abnormal findings. Laboratory studies show Hgb 13.5 g/dL, Hct 40.4%, MCV 84 fL, platelet count
248,500/microliter, and WBC count 7350/microliter. His prothrombin time is 12.1 seconds and partial
thromboplastin time is 40 seconds. Which of the following conditions is he most likely to have? -
Answers VWD (if severe may affect the function of the intrinsic pathway measured by the PTT. In many
cases of vWD the PT and the PTT and the platelet count will be normal.)
In an experiment, initiation of the coagulation system is studied by the addition of various compounds to
aliquots of normal patient plasma. After addition of a compound, the prothrombin time is measured
with one aliquot and the partial thromboplastin time with another aliquot. Addition of which of the
following compounds is most likely to produce clotting, as measured by the prothrombin time? -
Answers tissue factor
A 19-year-old man develops a sudden episode of mental confusion and weakness. On physical
examination he has 4/5 motor strength in his right arm. Laboratory studies show Hgb 14.5 g/dL, Hct
44.4%, MCV 89 fL, platelet count 227,800/microliter, and WBC count 6480/microliter. His prothrombin
time is 12 seconds and partial thromboplastin time 25 seconds. A year later he develops deep venous
thrombosis of his left lower leg. A mutation involving a gene encoding for which of the following is most
likely to be present in this man? - Answers Prothrombin
A 15-year-old boy has the sudden onset of dyspnea. On physical examination he has vital signs with T
37.1°C, P 90/minute, RR 25/minute, and BP 100/60 mm Hg. A pulmonary ventilation/perfusion scan
shows a large right perfusion defect. Laboratory studies show Hgb 13.9 g/dL, Hct 42%, MCV 91 fL,
platelet count 238,200/microliter, and WBC count 6170/microliter. His prothrombin time is 12.7 seconds
A 44-year-old man in acute distress is noted to have multiple ecchymoses of the skin that have
developed over the past 48 hours. His prothrombin time (PT) is 38 seconds and partial thromboplastin
time (PTT) 55 seconds. A CBC shows a WBC count of 5300/microliter, hemoglobin 8.1 g/dL, hematocrit
24.9%, MCV 99 fL, and platelet count 16,300/microliter. His D-Dimer test is very high. Which of the
following is the most likely diagnosis? - Answers DIC (Disseminated intravascular coagulopathy)
What does a positive D-Dimer mean? - Answers Generation of fibrin degradation products (widespread
activation of clotting)
What disease leads to prolonged bleeding or petechial hemorrhages? - Answers VWD (vonWillebrand
Disease)
A clinical study is performed with subjects who have thrombocytopenia <10,000/microliter. These
patients are observed to have defects in coagulation with spontaneous bleeding characterized by
multiple petechiae and purpura and stool samples positive for occult blood. What coagulation functions
is most likely to remain largely intact in these patients? - Answers Conversion of fibrinogen to fibrin
(driven by coagulation factor)
A 28-year-old woman has a history of easy bruising with minor trauma, frequent nosebleeds, and
menorrhagia. On examination purpuric areas are noted on her extremities. Laboratory studies show a
normal PT and normal PTT. Her Hgb is 12.8 g/dL, Hct 39.7%, MCV 91 fL, platelet count 88,500/microliter,
and WBC count 8160/microliter. Platelet function studies show that her platelets do not aggregate in
response to ristocetin. Which of the following deficiencies most likely explains her disease? - Answers
Glycoprotein Ib-IX (Bernard Soulier Syndrome)
A 35-year-old woman has noted small hemorrhages on her skin increasing in number over the past
month. On physical examination she has petechiae involving skin surfaces of her torso and extremities.
Laboratory studies show a normal PT and normal PTT. Her Hgb is 9.8 g/dL, Hct 29.4%, MCV 80 fL,
platelet count 276,300/microliter, and WBC count 7290/microliter. Platelet function studies are normal.
What the most likely diagnosis? - Answers Scurvy (capillary fragility)
A 12-year-old boy has had worsening problems with joint mobility involving his arms and legs,
particularly his knees and ankles, for the past 6 years. He has been receiving therapy for this condition.
On physical examination he has no visible petechiae or areas of purpura. Laboratory studies show that
his prothrombin time is 12 seconds and his partial thromboplastin time is 52 seconds. After addition of
an equivalent aliquot of normal plasma, his PTT is 40 seconds. His Hgb is 12.9 g/dL, platelet count
238,500/microliter, and WBC count 6620/microliter. What is the most appropriate statement regarding
his clinical condition? - Answers Transfusion of Factor VII is helpful (Hemophilia A)
A 69-year-old woman has had flank pain and a high fever for a week. On physical examination her
temperature is 38°C. There is left costovertebral angle tenderness. A urine culture is positive for
Escherichia coli. She then has a drop in blood pressure and in urine output. A blood culture grows
, Escherichia coli. Her prothrombin time is 34 seconds and her partial thromboplastin time 59 seconds.
Her platelet count is 11,000/microliter. Her D-dimer is elevated. Which of the following is the most likely
mechanism for development of her laboratory findings? - Answers Endothelial cell injury (DIC)
A clinical study is conducted comparing patients diagnosed with vonWillebrand disease (VWD) to
patients diagnosed with hemophilia A. Both groups of patients have documented problems of
hemostasis over a 10 year period. Which of the following complications is most likely to be seen more
frequently in the patients with hemophilia A? - Answers Bleeding in joints
This is caused by a deficiency in factor IX and leads to prolonged PTT - Answers Hemophilia B (coag.
factor deficiency)
A 30-year-old man experiences excessive bleeding following a wisdom tooth extraction. There is a family
history of similar problems. His mother had a history of menorrhagia. His sister has frequent nosebleeds.
Laboratory studies on this man show he has a normal PT, PTT, and platelet count. Which of the following
is the most likely diagnosis? - Answers VWD (Depending upon the type of mutation and severity of the
disease, the amount of bleeding can vary. Also, factor VIII levels may be affected and prolong the PTT in
some cases.)
A 38-year-old man has frequent nosebleeds that are difficult to stop. On physical examination there are
no abnormal findings. Laboratory studies show Hgb 13.5 g/dL, Hct 40.4%, MCV 84 fL, platelet count
248,500/microliter, and WBC count 7350/microliter. His prothrombin time is 12.1 seconds and partial
thromboplastin time is 40 seconds. Which of the following conditions is he most likely to have? -
Answers VWD (if severe may affect the function of the intrinsic pathway measured by the PTT. In many
cases of vWD the PT and the PTT and the platelet count will be normal.)
In an experiment, initiation of the coagulation system is studied by the addition of various compounds to
aliquots of normal patient plasma. After addition of a compound, the prothrombin time is measured
with one aliquot and the partial thromboplastin time with another aliquot. Addition of which of the
following compounds is most likely to produce clotting, as measured by the prothrombin time? -
Answers tissue factor
A 19-year-old man develops a sudden episode of mental confusion and weakness. On physical
examination he has 4/5 motor strength in his right arm. Laboratory studies show Hgb 14.5 g/dL, Hct
44.4%, MCV 89 fL, platelet count 227,800/microliter, and WBC count 6480/microliter. His prothrombin
time is 12 seconds and partial thromboplastin time 25 seconds. A year later he develops deep venous
thrombosis of his left lower leg. A mutation involving a gene encoding for which of the following is most
likely to be present in this man? - Answers Prothrombin
A 15-year-old boy has the sudden onset of dyspnea. On physical examination he has vital signs with T
37.1°C, P 90/minute, RR 25/minute, and BP 100/60 mm Hg. A pulmonary ventilation/perfusion scan
shows a large right perfusion defect. Laboratory studies show Hgb 13.9 g/dL, Hct 42%, MCV 91 fL,
platelet count 238,200/microliter, and WBC count 6170/microliter. His prothrombin time is 12.7 seconds
