Hemodynamics Flashcards
1
Q
- While camping, a 15-year-old boy is bitten by
a mosquito. At the site of the mosquito bite, his skin
turns red and a small but noticeable bump forms.
Which of the following terms best describes the
color change in the skin?
A. Lividity
B. Ecchymosis
C. Contusion
D. Congestion
E. Hyperemia
A
- Correct: Hyperemia (E).
The red discoloration of the skin is a sign of acute
inflammation due to the mosquito bite and occurs
due to dilation of blood vessels, an active process.
The correct term in this situation is hyperemia (E).
Congestion is a passive process, which results from
impaired venous return (D). Lividity is the postmortem
pooling of blood in the skin due to gravity (A). A contusion (i.e., bruise) is due to extravasation of
red blood cells into the tissue as a result of trauma
(C), and an ecchymosis is also due to extravasation of
red blood cells (B), as opposed to hyperemia, where
red blood cells should be essentially confined to the
blood vessels.
2
Q
- A 66-year-old male has a long-standing history
of congestive heart failure due to uncontrolled
hypertension and has had multiple admissions to the
hospital for treatment of pulmonary edema. During
his most recent admission, he sustains a fatal cardiac
dysrhythmia. Which of the following is likely to be
observed in this patient’s lungs at autopsy?
A. Dilated alveolar septal capillaries filled with red
blood cells
B. Fibrotic and thickened alveolar septal capillaries
C. Loss of alveolar septa, resulting in large airspaces
D. Congestion of centrilobular sinusoids
E. Diffuse macrovesicular steatosis of the liver
A
- Correct: Fibrotic and thickened alveolar septal
capillaries (B)
With congestive heart failure, a chronic process, causing
multiple episodes of pulmonary edema, chronic pulmonary congestion, characterized by fibrotic and thick alveolar septa and macrophages with hemosiderin
would be most characteristic of the clinical scenario
(B). For the most recent episode, dilated alveolar septal
capillaries filled with red blood cells would be appropriate;
however, it would not best describe the overall clinical scenario. For (C–E), see previous information.
3
Q
- A 71-year-old male with a history of poorly controlled
hypertension due to noncompliance with medications
is brought to the emergency room by his family
because of increasing shortness of breath. An X-ray of the chest reveals bilateral pleural effusions and enlargement
of the heart. Given these features, of the following,
which is the most likely causative mechanism for the
condition producing his shortness of breath?
A. Increased hydrostatic pressure
B. Increased vascular permeability
C. Decreased colloid osmotic pressure
D. Lymphatic obstruction
E. Sodium retention
A
- Correct: Increased hydrostatic pressure (A)
The fluid in the pleural cavities represents pulmonary
edema due to heart failure from the uncontrolled
hypertension. Although the other mechanisms listed
can lead to pulmonary edema, the most likely cause,
given the scenario, would be congestive heart failure.
Congestive heart failure will increase hydrostatic
pressure in the pulmonary vasculature, causing fluid
to leak into the surrounding space (A). For (B–E), see
previous information.
4
Q
- A 68-year-old male with poorly controlled
hypertension presents to the emergency room with
shortness of breath. A chest X-ray reveals bilateral
pleural effusions. An S3 gallop is heard and crackles
(rales) are present in both lung fields. Which of the
following pigments is most likely to be found within
macrophages in his lungs?
A. Bilirubin
B. Hemosiderin
C. Melanin
D. Lipofuscin
E. Calcium
A
- Correct: Hemosiderin (B).
This individual has a clinical scenario consistent with
congestive heart failure. In congestive heart failure,
a common histologic finding is heart-failure cells,
which are macrophages filled with hemosiderin that
are found in the alveolar airspaces (B). For (A, C–E),
see previous information.
5
Q
- A 56-year-old male presents to his physician
because of swelling in the right lower extremity distal
to the knee. He has a history of mild hypertension,
which is well controlled with medication. He also
reports no trauma to the extremity, and no skin infections
or other known sites of infection. On examination
edema is noted, with the circumference of the right calf
measuring 3 cm larger than the circumference of the
left calf. There is a palpable cord present. Of the following,
which aspect of the history, physical, or laboratory
testing would be most likely to indicate the cause?
A. AST/ALT levels
B. CK-MB levels
C. BUN/creatinine levels
D. Family history of colon cancer
E. History of recent surgery
A
- Correct: History of recent surgery (E)
This patient has sustained a deep venous thrombosis.
Given the unilateral nature, edema due to liver failure, renal failure, or heart failure is less likely (A–C). Unilateral edema of a lower extremity could be due to venous or lymphatic obstruction. A neoplasm would be a rare cause for unilateral swelling of a lower extremity (D). Of the choices, only the history of recent surgery would be expected to reveal a potential cause for this deep venous thrombosis (E).
6
Q
- A 40-year-old male is brought to the emergency
department by his wife because of his shortness
of breath. He reports the onset of a cough two days
prior with increasing shortness of breath. On arrival
his temperature is 100.5°F (38.0°C), his heart rate is
135/min, and blood pressure is 88/55 mm Hg. Physical
examination is unremarkable except for tachycardia.
The patient is alert and oriented. His leukocyte
count is 18,000/μL, his pCO2 on arterial blood gas is
30 mm Hg, and serum lactic acid is slightly elevated
at 4 mmol/L. A plain chest radiograph shows a right
lower lobe infiltrate. What is the most likely diagnosis?
A. Acute pulmonary embolism
B. Septic shock
C. Cardiogenic shock
D. Anaphylactic shock
E. Acute myocardial infarction
A
- Correct: Septic shock (B)
The patient has multiple diagnostic criteria for sepsis,
including fever, a leukocyte count > 12,000/μL, heart
rate > 90/min, and CO2 < 32 mm Hg (B). All of these findings can also be seen in acute pulmonary embolism;
however, the finding of an infiltrate on the chest radiograph is consistent with pneumonia and would not be expected in acute pulmonary embolism (A). There is no
additional information to suggest cardiogenic shock,
anaphylaxis, or acute myocardial infarction (C–E).
7
Q
- A 76-year-old man is evaluated in the emergency
department for hypotension and dyspnea. His temperature
is 97.8°F (36.5°C), pulse 125/min, and blood pressure
88/58 mm Hg. Bilateral crackles are present in the
lung fields. Pedal edema is noted bilaterally. His extremities
are cool, and his urine output is minimal. A plain
chest radiograph reveals cardiomegaly and pulmonary
edema. What is the pathophysiology of his shock?
A. Septic shock
B. Anaphylactic shock
C. Cardiogenic shock
D. Hypovolemic shock
E. Distributive shock
A
- Correct: Cardiogenic shock (C)
The patient has all the signs and symptoms of cardiogenic
shock (C). The presence of signs and symptoms of volume overload such as pedal and pulmonary edema would not be expected in the other types of shock (A–B, D–E).
8
Q
- In the previous clinical scenario, of the following,
which is most likely the underlying cause of this
man’s shock?
A. Acute pulmonary embolism
B. Acute right ventricular myocardial infarction
C. Pulmonary hypertension
D. Aortic stenosis
E. Pericardial tamponade
A
- Correct: Aortic stenosis (D)
Aortic stenosis can produce cardiogenic shock and
left ventricular failure resulting in pulmonary edema
(D). The other causes listed are associated with right
ventricular failure and would not be expected to
cause pulmonary edema (A–C, E).
9
Q
- A 67-year-old man is brought to the emergency
department with hypotension and tachycardia.
He has had no urine output. Which of the following
additional findings would suggest hypovolemia
rather than sepsis as the underlying cause of this
man’s low urine output?
A. Low leukocyte count
B. Elevated leukocyte count
C. Hypernatremia
D. Hyperglycemia
E. Elevated serum lactic acid
A
- Correct: Hypernatremia (C)
Leukocyte count is frequently low in sepsis, due to
bone marrow suppression (A). A high leukocyte count
may be seen either in sepsis, due to the response to
an infection, or in hypovolemia and dehydration
because of the hemoconcentration that occurs (B).
Hyperglycemia could be seen in either septic shock
or hypovolemic shock, due to cortisol release in the
stress response (D). Elevated serum lactic acid levels
are a common finding in all forms of shock (E).
Hypernatremia occurs when there is severe loss of
free water (dehydration), a situation that would be
consistent with hypovolemic shock but not septic
shock (C).
10
Q
- A 76-year-old man is found dead at home.
Microscopic examination of samples of the liver and
lung reveals centrilobular hemorrhagic necrosis of
the liver and hemosiderin-laden macrophages in the
lungs. Of the following, what additional finding at
autopsy would be most likely?
A. Pleural effusion
B. Aortic dissection
C. Deep venous thrombosis
D. Disseminated intravascular coagulation
E. Pericardial tamponade
A
- Corect: Pleural effusion (A)
Centrilobular hemorrhagic necrosis of the liver (“nutmeg
liver”) and hemosiderin-laden macrophages in the lungs are manifestations of chronic passive congestion, which is seen in chronic heart failure. Of the choices, pleural effusions are most characteristic of congestive heart failure (A). The other options (B–E) would not be expected as routine autopsy findings in congestive heart failure.
11
Q
- A 60-year-old female status post right radical
mastectomy and right axillary lymph node dissection
develops chronic edema of the right arm. Which
of the following is the cause of her edema?
A. Increased plasma oncotic pressure
B. Renal sodium retention
C. Increased interstitial protein
D. Increased vascular permeability
E. Decreased plasma albumin
A
- Correct: Increased interstitial protein (C)
The lymphatic system returns proteins back to the
intravascular space that have been forced out of the
arterial capillary system and into interstitial space by
hydrostatic pressure. Up to 50% of serum proteins are
transported via the lymphatic route each day (C). For
(A–B, D–E), see previous information.
12
Q
- A 79-year-old male nursing home resident with
dementia is admitted to the hospital for failure to
thrive. According to his primary caregiver he has taken
very little fluids or food over the preceding three weeks.
On admission his serum sodium is 165 mmol/L, and he
subsequently receives a large amount of free water in
the form of intravenous D5W over a two-hour period.
Shortly after finishing the fluids he becomes unresponsive.
He dies after a brief attempt at resuscitation. Blood
for a chemistry panel is drawn during resuscitation,
with laboratory testing revealing the serum sodium to
be 124 mmol/L. Examination of the brain at autopsy is
most likely to reveal which of the following findings?
A. Liquefactive necrosis
B. Acute thrombosis of the middle cerebral artery
C. Narrowed sulci and distended gyri
D. Passive venous congestion
E. Diffuse axonal injury
A
- Correct: Narrowed sulci and distended gyri (C)
This patient sustained cerebral edema due to
overcorrection of hypernatremia. The finding of
narrowed sulci and distended gyri is the classic
description of the edematous brain (C). Liquefactive
necrosis would be seen in acute infarction, as
would middle coronary artery thrombosis; however,
the clinical scenario gives no indication of stroke (A,
B). Passive venous congestion would be expected in
strangulation or in central venous thrombosis (D).
Diffuse axonal injury is seen in trauma (E).
13
Q
- A 58-year-old man with a history of deep
venous thrombosis following right total knee replacement
is recovering from multiple injuries sustained
in a motor vehicle collision. His injuries include
fractures to both tibial plateaus. He is on subcutaneous
unfractionated heparin for prevention of deep
venous thrombosis. On his 6th hospital day his platelet
count dropped from 250,000/μL to 110,000/μL. He
is otherwise recovering well with no complications,
and a lower extremity Doppler is performed, which
is negative for deep venous thrombosis. Which of the
following additional tests would be most helpful in
determining the cause of his thrombocytopenia?
A. PT and PTT
B. Anti-platelet factor 4 antibody
C. Protein C activity
D. Protein S activity
E. Factor Xa level
A
- Correct: Anti-platelet factor 4 antibody (B)
The > 50% drop in the platelet count is suggestive of
heparin-induced thrombocytopenia, and his prior
treatment for deep venous thrombosis would likely
have meant prior exposure to heparin. Heparin induced
thrombocytopenia is caused by antibodies to heparin-platelet factor-4 complexes (B). Coagulation studies (PT, PTT, Factor Xa level) are unlikely to be helpful as these tests mainly assess coagulation rather than platelet function (A, E). Protein C and S levels would be indicated in the workup for recurrent deep venous thrombosis, or for unprovoked deep venous thrombosis in patients under age 50 (C, D).
14
Q
- A 37-year-old female with a history of deep
venous thrombosis during her first pregnancy and
two spontaneous abortions is evaluated in the emergency
department. Forty minutes prior to arrival she
experienced the sudden onset of weakness of the
right face, right arm, and right leg. Neurologic examination
reveals flaccid paralysis of the right side of the
body with expressive aphasia without visual field
defect. Magnetic resonance imaging (MRI) of the
brain and basic lab work including complete blood
count, prothrombin time (PT), and activated thromboplastin
time (aPTT) are ordered in the emergency
department. The treating physician administers
tissue plasminogen activator (t-PA) to the patient
according to hospital protocol in the treatment of
acute stroke. Which of the following is true regarding
the mechanism of t-PA?
A. t-PA prevents platelet activation by inhibiting
GpIIb-IIIa complex.
B. t-PA prevents platelet activation by inhibiting
GpIb receptors.
C. t-PA increases the degradation of fibrin.
D. t-PA binds anti-thrombin III, leading to thrombin
inactivation.
E. t-PA binds and inactivates clotting factors.
A
- Correct: t-PA increases the degradation of
fibrin. (C)
t-PA converts plasminogen to plasmin, which in turn
cleaves fibrin, releasing fibrin degradation products
(C). By this mechanism, t-PA prevents further deposition
of thrombin and thus clot propagation. GpIb and GpIIb-IIIa are platelet membrane glycoproteins present on the platelet surface that promote platelet aggregation (A, B). Inhibition of GpIIb-IIIa is the mechanism of action of eptifibatide (Intergrilin) (A). There is no drug currently available that inhibits GpIa. Heparin, not t-PA, activates anti-thrombin III (D). (E) is incorrect because t-PA acts by promoting fibrinolysis, not by inactivating clotting factors.
15
Q
- Ristocetin is an antibiotic, which is no longer
in use, that causes platelet agglutination by facilitating
binding of von Willebrand’s factor (vWF)
to GpIb. Two tests used in the workup of von Willebrand’s
disease are the ristocetin cofactor assay and
the ristocetin-induced platelet aggregation (RIPA).
The ristocetin cofactor assay measures the ability of
formalin-fixed (i.e., dead) control platelets to agglutinate
in the patient’s plasma. The ristocetin-induced
platelet aggregation test involves adding ristocetin
to a sample of the patient’s platelet-rich plasma.
Which results on the ristocetin cofactor assay and
the RIPA would be consistent with Bernard-Soulier’s
syndrome?
A. Normal agglutination on ristocetin cofactor assay
and normal agglutination on RIPA
B. Normal agglutination on ristocetin cofactor assay
and hypoactive agglutination on RIPA
C. Hypoactive agglutination on ristocetin cofactor
assay and normal agglutination on RIPA
D. Hypoactive agglutination on ristocetin cofactor
assay and hypoactive agglutination on RIPA
E. Hyperactive agglutination on ristocetin cofactor
assay and normal agglutination on RIPA
A
- Correct: Normal agglutination on ristocetin
cofactor assay and hypoactive agglutination on
RIPA (B)
Ristocetin induces platelet aggregation in a von Willebrand factor (vWF) dependent mechanism by promoting
the binding of vWF to GpIb. The ristocetin cofactor assay is an indirect measurement of von Willebrand’s factor, which uses control platelets and measures the amount of ristocetin induced platelet agglutination. In von Willebrand’s disease, caused by a deficiency of the vWF, platelet agglutination would be hypoactive on both the ristocetin cofactor assay and the RIPA (D). Bernard-Soulier’s disease is caused by a genetic deficiency of glycoprotein Ib (GpIb) on platelets. In Bernard-Soulier’s disease ristocetininduced platelet agglutination would be normal on the ristocetin cofactor assay (which uses control
platelets) and hypoactive on the RIPA (which uses the patient’s own, in this case defective, platelets) (B). For (A, C, E), see previous information.
16
Q
- A 17-year-old male sustains a mid-shaft
femur fracture after a fall from a horse. The fracture
is repaired operatively and the patient is discharged.
On the second postoperative day he becomes acutely
dyspneic. In the emergency department he is
hypoxic and tachypneic, appears confused, and has a
petechial rash on his neck and anterior thorax. What
is the most likely diagnosis?
A. Aortic dissection
B. Fat embolism
C. Venous thromboembolism
D. Acute myocardial infarction
E. Disseminated intravascular coagulation
A
- Correct: Fat embolism (B)
The rapid onset of respiratory failure associated with
petechiae and neurologic dysfunction 1 to 3 days
after a long bone fracture is classic for fat embolism
syndrome (B). The presence of confusion and petechiae
make venous thromboembolism less likely (C). There is no history to suggest aortic dissection, acute myocardial infarction, or disseminated intravascular coagulation (A, D, E).
17
Q
- A 23-year-old man is flying home from a
10-day scuba diving vacation. One hour into the
flight he develops some mild to moderate pain in his
shoulders and knees. Shortly thereafter he reports a
substernal burning sensation with inspiration that
is associated with low back pain. By the time the
flight lands, which is four hours after takeoff, he is
unable to move his legs. He is immediately taken to
the nearest hospital, but dies of respiratory failure en
route. Which of the following would have reduced
his risk of developing this illness?
A. Delaying his flight home for 48 hours
B. Wearing insect repellent during his trip
C. Taking a dose of aspirin for a week before and
during his trip
D. Walking frequently during his airplane flight
E. Avoiding dental work a month prior to his trip
A
- Correct: Delaying his flight home for 48
hours (A)
This man’s symptoms are characteristic of severe
decompression sickness (DCS). Mild cases of DCS usually
present with mild joint pains, a mottled appearance
of the skin, and pruritis. In severe cases, gas
embolism causes damage to the spinal cord resulting
in paralysis. Air travel immediately after scuba diving
increases the risk of decompression sickness because
of the low atmospheric pressure at altitude (A). There
is no evidence that aspirin can reduce the risk of DCS
(C). For (B, D–E), see previous information.
18
Q
- A 76-year-old woman is found down at home
by a relative and is unresponsive on arrival to the
emergency department. A CT scan of the head preformed
shortly after arrival shows multiple infarcts
of the right and left cerebral hemispheres and an
infarct of the cerebellum, which were confirmed
with magnetic resonance imaging (MRI) of the brain.
Which of the following tests is most likely to reveal
the cause of her strokes?
A. A complete blood count
B. Bilateral lower extremity venous Doppler
C. Bilateral lower extremity arterial Doppler
D. Cerebral angiogram
E. Transesophageal echocardiogram
A
- Correct: Transesophageal echocardiogram (E)
The presence of multiple cerebral infarcts suggests
embolic stroke. Emboli from thrombi of the left heart
or the thoracic aorta would be most likely; thus, a
transesophageal echocardiogram is the most appropriate
diagnostic test (E). A complete blood count is
unlikely to be helpful unless the cause is bacterial
endocarditis, which would be much less common in
this patient population than cardiac thrombus (A).
Deep venous thrombosis would not cause arterial
emboli in the absence of a right to left cardiac shunt,
making lower extremity venous Doppler unhelpful
(B). Arterial Doppler of the lower extremities, being
distal, again would not be helpful (C). Finally since
in-situ thrombosis is unlikely to happen in multiple
vascular territories simultaneously, a cerebral angiogram
would not add any additional information (D).
19
Q
- A 72-year-old man with morbid obesity,
hypertension, and diabetes mellitus is evaluated by
his primary care physician for progressively worsening
edema of the lower extremities over the preceding
years. He reports pain in both legs with standing
and walking but improvement in the pain and edema
with elevation of the legs. His body mass index is
39.5 kg/m2. His vital signs are normal. Auscultation
of the heart and lungs is normal. He has 3+ pitting
edema of the bilateral lower extremities with normal
warmth, mild tenderness and numerous varicose
veins. Inspection of the skin reveals a reddish-brown
hyperpigmented and indurated dermatitis involving
the anterior lower legs bilaterally. What is the most
likely underlying cause of the patient’s symptoms?
A. Damage to valves in the deep venous system of
the legs
B. Acute thrombosis of the deep venous system of
the legs
C. Atherosclerotic disease of the bilateral iliac
arteries
D. Impaired lymphatic drainage of the legs
E. Bacterial soft tissue infection of the legs
A
- Correct: Damage to valves in the deep venous
system of the legs (A)
This patient has the classic signs and symptoms of
chronic venous insufficiency, including lipodermatosclerosis, varicose veins, and edema. The underlying mechanism is damage to the valves of the deep and perforating system, resulting in venous reflux
and venous hypertension (A). A history of prior deep
venous thrombosis is common (post-phlebitic syndrome);
however, given the bilateral symptoms and gradual onset, an acute DVT in this patient is unlikely (B). Atherosclerotic disease with arterial insufficiency would not cause edema (C), and the presence of characteristic skin changes (lipodermatosclerosis) and varicosities helps distinguish venous insufficiency from lymphedema (D). Mistaking lipodermatosclerosis for cellulitis is a common diagnostic error in the evaluation of chronic venous insufficiency (E).
20
Q
- A 78-year-old man with chronic atrial fibrillation
presents with abdominal pain. The patient
reports the pain started 3 hours ago, is very severe,
and is periumbilical. His temperature is 99.0°F
(37.0°C), pulse 110/min, and blood pressure 98/58
mm Hg. The patient appears to be in severe pain.
Physical examination is remarkable for an irregularly
irregular heart rhythm and mild abdominal
distension. The abdomen is mildly tender. His leukocyte
count is 19.3 × 103/μL, hemoglobin is 19.0 g/
dL, and serum bicarbonate is 18 mmol/L. Five hours
after arrival his condition deteriorates, his abdomen
becomes grossly distended, his bowel sounds
become inaudible, and he dies. Which of the following
is the most likely diagnosis?
A. Mesenteric embolic infarction
B. Ruptured abdominal aortic aneurysm
C. Acute appendicitis
D. Acute diverticulitis
E. Small bowel obstruction
A
- Correct: Mesenteric embolic infarction (A)
This patient presents with abdominal pain out of
proportion to physical examination findings and has
atrial fibrillation, a risk factor for systemic embolism.
This is a classic presentation of mesenteric infarction
(A). For (B–E), see previous information.
21
Q
- A 55-year-old male with well-controlled type
2 diabetes mellitus, hypertension, and paroxysmal
atrial fibrillation presents with acute onset of right
flank pain with hematuria. His temperature is 98.8°F
(37°C), pulse is 90/min, blood pressure is 155/92 mm
Hg, respirations are 18/min, and O2 saturation is 98% on
room air. On examination he appears to be in moderate
pain, his lungs are clear, he has an irregularly irregular
rhythm, and his right flank is tender to palpation. His
leukocyte count is 12 × 103/μL, creatinine is 1.8 mg/dL
(from a value of 1.1 mg/dL six months previously), and
his aminotransferases are normal. Urinalysis shows
numerous red cells with no white cells and no casts.
Noncontrast helical CT scan of the kidneys and collection
system is unremarkable. Of the following, what is
the most likely diagnosis?
A. Acute pyelonephritis
B. Ureterolithiasis
C. Acute appendicitis
D. Glomerulonephritis
E. Renal infarction
A
- Correct: Renal infarction (E)
This patient has embolic renal infarction from atrial
fibrillation (E). In the absence of urine leukocytes,
white cell casts, or fever, pyelonephritis is unlikely
(A). The absence of a stone on helical CT of the kidneys
makes a kidney stone unlikely (B). Appendicitis should be considered; however, appendicitis usually presents with right lower quadrant rather than right flank pain and would not cause hematuria (C). Glomerulonephritis would not cause flank pain (D).
22
Q
- A 32-year-old woman has routine lab work
done as part of her annual physical examination.
She returns to the clinic 3 days after her blood draw
complaining of pain in the left antecubital fossa. On
examination there is mild erythema without induration,
no palpable fluctuence, and the basilic vein is
tender and palpated as a nodular “cord.” What is the
appropriate management?
A. Anticoagulation with Coumadin
B. Oral antibiotics
C. Warm compresses
D. Topical corticosteroids
E. Incision and drainage
A
- Correct: Warm compresses (C)
The management of uncomplicated superficial
venous thrombophlebitis is symptomatic. Warm
compresses and nonsteroidal anti-inflammatory
medication are usually effective (C). In the absence of
significant erythema and induration or fever, antibiotics
are unnecessary (B). Topical steroids would be indicated for atopic dermatitis but would not help in this case (D). There is no evidence of abscess or septic thrombophlebitis; thus, no indication for incision
and drainage (E). Anticoagulation is unnecessary (A).
23
Q
- A pathologist is examining tissue removed
from a 57-year-old deceased male. The tissue has
preservation of normal architecture; however, there
is loss of nuclear and cytoplasmic basophilia. Associated
with these changes are abundant extravasated
red blood cells in the tissue. The man had no resuscitation
performed. Of the following, where did this
tissue most likely originate?
A. The heart
B. A kidney
C. The spleen
D. The brain
E. A lung
A
- Correct: A lung (E)
The tissue description is that of coagulative necrosis,
with preservation of architecture but loss of basophilia.
The abundant extravasated red blood cells indicate
a red infarct, which most commonly occur in the
liver and lungs, organs with dual blood supplies (E).
Organs with single blood supplies, such as the heart,
kidney, and spleen, have white infarcts unless there
has been reperfusion (A–C). The brain can have red
infarcts with venous lesions; however, liquefactive
and not coagulative necrosis is most common (D).
24
Q
- A 22-year-old female in active labor suddenly
develops hypotension and dyspnea. She becomes
hypoxic and is intubated for acute respiratory failure.
Chest radiograph shows acute pulmonary edema.
She dies prior to delivery. Which of the following is
most likely to be found at autopsy?
A. Left ventricular hypertrophy
B. Femoral vein deep venous thrombosis
C. Plaque rupture in the left anterior descending
coronary artery
D. Disseminated intravascular coagulation
E. Thrombus in the right main pulmonary artery
A
- Correct: Disseminated intravascular
coagulation (D)
The patient in this scenario dies of an acute catastrophic
cardiovascular/pulmonary event (amniotic fluid embolism). Left ventricular hypertrophy is an adaptation to chronic stress (A). (B, E) would be expected if the patient had died of pulmonary embolism; however, pulmonary edema is rare in pulmonary embolism and common in amniotic fluid embolism. Acute myocardial infarction from a ruptured atherosclerotic plaque (C) would be extremely rare in a 22-year-old female. Common pathologic findings in amniotic fluid embolism include fetal squamous cells and hair in the arterioles, disseminated intravascular coagulation, pulmonary edema, and diffuse alveolar damage (D).
25
Q
- A 67-year-old woman has a central venous
catheter placed during hospitalization for dehydration.
The catheter is placed using guidewire technique
and ultrasound guidance, and the tip of the
catheter is demonstrated to be in good position in
the superior vena cava. On the third hospital day
the nurse finds the patient sitting up in bed with
the venous catheter partially dislodged. The nurse
removes the catheter and holds pressure; however,
the patient rapidly becomes tachycardic and
hypoxic. Electrocardiogram shows sinus tachycardia
and a new right axis deviation. What is the most
likely diagnosis?
A. Pulmonary embolism
B. Air embolism
C. Acute myocardial infarction
D. Aortic dissection
E. Sepsis
A
- Correct: Air embolism (B)
The history of sudden onset of respiratory failure
with central venous catheter placement or removal
in the upright position is highly suggestive of an air
embolism (B). The EKG findings of tachycardia and
right axis deviation are indicative of right ventricular
overload. Pulmonary embolism could present in a
similar fashion; however, again, the history of puncture
of a large central vein makes air embolism more
likely (A). For (C–E), see previous information.
26
Q
- A 63-year-old male undergoes left heart catheterization
in preparation for possible aortic valve
replacement to treat severe aortic regurgitation. The
procedure revealed extensive calcification in the
thoracic aorta and moderate nonobstructive coronary
artery disease. A week after the procedure he
presents to his primary care physician complaining
that his left big toe has turned blue. In addition to
a patchy cyanosis of several toes on both feet, he is
noted to have livedo reticularis of the lower extremities
and elevation of the serum creatinine. Pulses are
brisk in both lower extremities. What is the most
likely diagnosis?
A. Granulation tissue in the dermis
B. Excessive collagen deposition in the dermis
C. Foreign body granulomas in the dermis
D. Fibrin thrombi in the arterioles of the dermis
E. Cholesterol deposition in arterioles of the dermis
A
- Correct: Cholesterol deposition in arterioles
of the dermis (E)
The history of recent angiography in the setting of
atherosclerotic disease in the setting of acute kidney
injury and livedo reticularis is highly suggestive of
cholesterol embolization (E). “Blue toe syndrome”
is a less common, but classic finding in cholesterol
embolization. (A, B) describe findings associated
with wound healing and scar tissue formation,
respectively. Foreign body granulomas are uncommon
and inconsistent with the clinical presentation;
however, occasionally macrophage granulomas
can be seen in cholesterol embolism but would be
expected in the arteriole, not the dermis (C). (D)
describes characteristic findings in disseminated
intravascular coagulation.
27
Q
- A 57-year-old man is evaluated in the emergency
room for sudden onset of left hemiparesis,
which began 45 minutes prior to his arrival. A CT
scan of the head in the emergency department is
unremarkable. t-PA is not administered because of
his uncontrolled hypertension. He is admitted to
a neurologic ICU, and a 2D echocardiogram is performed,
which shows a mobile mural thrombus of
the left ventricle. Which of the following additional
findings are likely to be found on echocardiogram?
A. Atrial fibrillation
B. A large area of poorly contracting left ventricular
muscle
C. Hypokinetic right ventricle and dilated
pulmonary artery
D. Aortic valve calcification and stenosis
E. Mitral valve vegetation
A
- Correct: A large area of poorly contracting
left ventricular muscle (B)
This patient has developed a ventricular mural
thrombus, which most commonly develops after a
myocardial infarction. The damaged ventricular wall
is highly thrombogenic, and poor contractility of the
damaged myocardium creates turbulence that predisposes
to thrombus formation. If the infarct results
in ventricular wall aneurysm, the risk of thrombus
formation is increased further. The infarct should
be visible on echocardiogram as an akinetic portion
of the ventricular wall (B). Thrombi that form as a
result of atrial fibrillation are usually visualized in
the atria or atrial appendage (A). (C) describes findings
typical of pulmonary embolism. Neither (D) nor
(E) are associated with left ventricular thrombus in
the absence of other pathology.
28
Q
- A 27-year-old male presents with his second
unprovoked deep venous thrombosis. He is started
on Coumadin and returns in 5 days to check his INR
(International Normalized Ratio). Which of the following
tests would be least useful to order at his
follow-up visit?
A. Homocysteine level
B. Prothrombin Gene Mutation (G20210A)
C. Factor V Leiden
D. Proteins C and S activity
E. Antiphospholipid antibody
A
- Correct: Proteins C and S activity (D)
Proteins C and S are potent inhibitors of several clotting
factors. Inherited deficiency of either will lead
to a hypercoagulable state. However, Proteins C and
S and antithrombin III levels are often low in the setting
of acute VTE (venous thromboembolism) due to
consumption by the clotting process. Furthermore,
both proteins C and S are vitamin K dependent and
will be low in the setting of Coumadin therapy (D).
The remainder of the laboratory studies (A–C, E)
are all appropriate in the initial workup for possible
thrombophilia.
29
Q
- A 30-year-old man involved in a motor vehicle
collision is brought in by EMS for severe bleeding
from a laceration of the femoral artery. Shortly after
arrival to the emergency department, his systolic
pressure has dropped to 65 mm Hg, and his heart
rate is 140. He is noted to be confused, and his urine
output is low. He is receiving a blood transfusion
and is started on Vasopressin. Which of the following
physiologic effects would not be expected from
Vasopressin?
A. Increase in systolic blood pressure
B. Platelet activation
C. Vasoconstriction
D. Hyponatremia
E. Increased renal tubular sodium absorption
A
- Correct: Increased renal tubular sodium
absorption (E)
The increase in renal tubular sodium reabsorption
(E) seen in hypovolemia is due to activation of the
renin-angiotensin-aldosterone system, not vasopressin
secretion. Vasopressin (antidiuretic hormone)
plays a role both in vascular tone and blood pressure
control and in water homeostasis. Vasopressin, as its
name implies, has vasoconstrictive effects (C), which
raises blood pressure (A) and promotes hemostasis.
It also increases water absorption on the distal nephron
and thus will cause hyponatremia if its secretion
is uncoupled from regulation by plasma osmolality,
as is the case in severe hypovolemia (D). It also activates
platelets (B).
30
Q
- A 37-year-old female with a history of deep
venous thrombosis during her first pregnancy and
two spontaneous abortions is being evaluated in
the emergency department. Forty minutes prior to
arrival she experienced the sudden onset of weakness
of the right face, right arm, and right leg. Neurologic
examination reveals flaccid paralysis of the
right side of the body with expressive aphasia without
visual field defect. Magnetic resonance imaging
(MRI) of the brain and basic lab work including
complete blood count, prothrombin time (PT), and
activated thromboplastin time (aPTT) are ordered in
the emergency department. Which of the following
is most likely to be found on the brain MRI?
A. Acute stroke of the right anterior cerebral artery
B. Acute stroke of the left anterior cerebral artery
C. Acute stroke of the right middle cerebral artery
D. Acute stroke of the left middle cerebral artery
E. Acute stroke of the right posterior cerebral artery
F. Acute stroke of the left posterior cerebral artery
A
- Correct: Acute stroke of the left middle
cerebral artery (D)
A middle cerebral artery (MCA) stroke would be
expected to cause neurologic deficits of the contralateral
arm, leg, and face (D). The presence of aphasia in this case indicates damage of the left posterior inferior frontal gyrus (Broca’s area). Anterior cerebral artery (ACA) strokes are less common and would produce contralateral hemiparesis but would not produce hemifacial weakness (A, B). The classic finding in posterior cerebral artery (PCA) stroke is homonymous hemianopsia, with larger PCA strokes producing contralateral hemiparesis and hemisensory loss (E, F).
31
Q
- In the previous scenario, which of the following
clinical or laboratory findings would suggest a
diagnosis other than antiphospholipid antibody syndrome
(APS)?
A. Prolonged activated partial thromboplastin time
(aPTT)
B. Positive VDRL test
C. Low platelet count
D. Positive antinuclear antibody (ANA)
E. Elevated homocysteine levels
A
- Correct: Elevated homocysteine levels (E)
Elevated homocysteine levels suggest a diagnosis of
hyperhomocysteinemia (E). Inherited deficiency of
cystathione β-synthetase or methylene-tetrahydrofolate
reductase can cause a familial hypercoagulable
state characterized by venous and arterial thrombosis
and elevated serum homocysteine levels. Prolongation
of aPTT can be seen in antiphospholipid antibody syndromes (APS) with Lupus Anticoagulant (A). Thrombocytopenia is a common manifestation of APS (C). Despite low platelet counts, these patients are prone to thrombosis rather than bleeding. A positive antinuclear antibody is suggestive of systemic
lupus, a common cause of secondary APS (D). VDRL
(Venereal Disease Research Laboratory) antigen consists
of cardiolipin-cholesterol-lecithin mixtures that
may produce a false positive syphilis test in patients
with APS who have anticardiolipin antibodies (B).
