Usmle Club Session No. 3
December 5, 2013
A 20-year-old woman presents to the Emergency
Department after being dumped in the ambulance
bay with a note that said only that “she was doing
Ecstasy at a party when she became unconscious.”
This patient currently remains unconscious, with a heart
rate of 140 bpm, temperature of 103.5°F, pinpoint
pupils, absent bowel sounds, blood pressure of 85/40
mm Hg, profuse sweating, and oxygen saturation of
86 percent on room air. Which of the following would
not be a clinical manifestation of an Ecstasy patient?
A. Tachycardia.
B. Hyperthermia.
C. Pinpoint pupils.
D. Diaphoresis.
E. Respiratory depression.
1
A 20-year-old woman presents to the Emergency
Department after being dumped in the ambulance
bay with a note that said only that “she was doing
Ecstasy at a party when she became unconscious.”
This patient currently remains unconscious, with a heart
rate of 140 bpm, temperature of 103.5°F, pinpoint
pupils, absent bowel sounds, blood pressure of 85/40
mm Hg, profuse sweating, and oxygen saturation of
86 percent on room air. Which of the following would
not be a clinical manifestation of an Ecstasy patient?
A. Tachycardia.
B. Hyperthermia.
C. Pinpoint pupils.
D. Diaphoresis.
E. Respiratory depression.
1
Correct answer = C. Tachycardia, hyperthermia,
diaphoresis, and unconsciousness are typical signs and
symptoms of ecstasy overdose. Pinpoint pupils as
well as absent bowel sounds, low oxygen saturation
(respiratory depression), and hypotension are good
indicators of opioid overdose. This is likely a multidrug
overdose.
A 41-year-old male pocketwatch maker reports
to the Emergency Department after he was found
unconscious on the floor of the shop by a coworker.
The coworker states that the patient complained of
being cold this morning around 8 a.m. (the central
heat was broken, and the outdoor temperature was
34°F) and that since noon, he had been complaining
of headache, drowsiness, confusion, and nausea.
The clinician notices that he has cherry red lips and
nail beds. What is the most likely toxin causing his
signs and symptoms?
A. Asbestos.
B. Cyanide.
C. Chloroform.
D. Carbon monoxide.
E. Ecstasy.
2
A 41-year-old male pocketwatch maker reports
to the Emergency Department after he was found
unconscious on the floor of the shop by a coworker.
The coworker states that the patient complained of
being cold this morning around 8 a.m. (the central
heat was broken, and the outdoor temperature was
34°F) and that since noon, he had been complaining
of headache, drowsiness, confusion, and nausea.
The clinician notices that he has cherry red lips and
nail beds. What is the most likely toxin causing his
signs and symptoms?
A. Asbestos.
B. Cyanide.
C. Chloroform.
D. Carbon monoxide.
E. Ecstasy.
2
Correct answer = D. Although watch makers and
other professionals who use electroplating may be
at higher risk for cyanide exposure because many
plating baths use cyanide-containing ingredients,
this patient shows classic signs of carbon monoxide
poisoning, such as cherry red lips and nail beds,
headache, confusion, nausea, and drowsiness
leading to unconsciousness.
The history also leads us to believe that this person
may have been using a stove or space heater
to stay warm. Asbestos poisoning commonly first
presents as lung cancer or mesothelioma. Cyanide in
low doses can present with loss of consciousness,
headache, and confusion and there is typically
giddiness in the early stages, breathing with difficulty,
and pink skin (not just lips and nails), and then later
rapidly progresses to deep coma and death.
Chloroform can cause dizziness, fatigue, and
unconsciousness, but these patients do not present
with cherry red lips and nails. These symptoms are
not consistent with Ecstasy overdose, in which
hyperthermia, not “feeling cold” is typically seen.
An elderly diabetic patient is admitted to the hospital
with pneumonia. The sputum culture stains for a
gram-negative rod. The patient is started on IV ampicillin.
Two days later, the patient is not improving,
and the microbiology laboratory reports the organism
to be a b-lactamase producing H. influenzae.
What course of treatment is indicated?
A. Continue with the IV ampicillin.
B. Switch to IV cefotaxime.
C. Switch to oral vancomycin.
D. Add gentamicin to the ampicillin therapy.
3
An elderly diabetic patient is admitted to the hospital
with pneumonia. The sputum culture stains for a
gram-negative rod. The patient is started on IV ampicillin.
Two days later, the patient is not improving,
and the microbiology laboratory reports the organism
to be a b-lactamase producing H. influenzae.
What course of treatment is indicated?
A. Continue with the IV ampicillin.
B. Switch to IV cefotaxime.
C. Switch to oral vancomycin.
D. Add gentamicin to the ampicillin therapy.
3
Correct answer = B. Cefotaxime, a third-generation
cephalosporin, is not susceptible to hydrolysis by
b-lactamase, is bactericidal, and has few adverse
effects. To continue the ampicillin is not appropriate,
because the organism is resistant to it. Vancomycin
is used in the treatment of serious infections caused
by b-lactamase resistant, gram-positive microorganisms
(H. influenzae is gram-negative). Although gentamicin
has some activity against H. influenzae, it also causes
adverse effects, such as nephrotoxicity, which may harm
the patient.
A patient with degenerative joint disease is to undergo
insertion of a hip prosthesis. To avoid complications
due to postoperative infection, the surgeon
will pretreat this patient with an antibiotic. This hospital
has a significant problem with MRSA. Which of
the following antibiotics should the surgeon select?
A. Ampicillin.
B. Imipenem/cilastatin.
C. Gentamicin/piperacillin.
D. Vancomycin.
E. Cefazolin.
4
A patient with degenerative joint disease is to undergo
insertion of a hip prosthesis. To avoid complications
due to postoperative infection, the surgeon
will pretreat this patient with an antibiotic. This hospital
has a significant problem with MRSA. Which of
the following antibiotics should the surgeon select?
A. Ampicillin.
B. Imipenem/cilastatin.
C. Gentamicin/piperacillin.
D. Vancomycin.
E. Cefazolin.
4
Correct answer = D. The only antibiotic on the list
that is effective against MRSA is vancomycin.
A 45-year-old male who received a renal transplant
3 months previously and is being maintained on
prednisone, cyclosporine, and mycophenolate mofetil
is found to have increased creatinine levels, and a kidney
biopsy indicating severe rejetion. Which of the
following courses of therapy would be appropriate?
A. Increased dose of prednisone.
B. Hemodialysis.
C. Treatment with rabbit antithymocyte globulin.
D. Treatment with sirolimus.
E. Treatment with azathioprine.
5
A 45-year-old male who received a renal transplant
3 months previously and is being maintained on
prednisone, cyclosporine, and mycophenolate mofetil
is found to have increased creatinine levels, and a kidney
biopsy indicating severe rejetion. Which of the
following courses of therapy would be appropriate?
A. Increased dose of prednisone.
B. Hemodialysis.
C. Treatment with rabbit antithymocyte globulin.
D. Treatment with sirolimus.
E. Treatment with azathioprine.
5
Correct answer = C. This patient is apparently undergoing
an acute rejection of the kidney. The most
effective treatment would be administration of an
antibody. Increasing the dose of prednisone may
have some effect, but would not be enough to treat
the rejection. Sirolimus is used prophylactically with
cyclosporine to prevent renal rejection but is less
effective when an episode is occurring. Furthermore,
the combination of cyclosporine and sirolimus is
more nephrotoxic than cyclosporine alone. Azathioprine
has no benefit over mycophenolate.
A 9-year-old girl has severe asthma, which required
three hospitalizations in the last year. She is now
receiving therapy that has greatly reduced the frequency
of these severe attacks. Which of the following
therapies is most likely responsible for this
benefit?
A. Albuterol by aerosol.
B. Ipratropium by inhaler.
C. Fluticasone by aerosol.
D. Theophylline orally.
E. Zafirlukast orally.
6
A 9-year-old girl has severe asthma, which required
three hospitalizations in the last year. She is now
receiving therapy that has greatly reduced the frequency
of these severe attacks. Which of the following
therapies is most likely responsible for this
benefit?
A. Albuterol by aerosol.
B. Ipratropium by inhaler.
C. Fluticasone by aerosol.
D. Theophylline orally.
E. Zafirlukast orally.
6
Correct answer = C. Administration of a corticosteroid
directly to the lung significantly reduces the frequency
of severe asthma attacks. This benefit is accomplished
with minimal risk of the severe systemic adverse effects of
corticosteroid therapy. Albuterol is only used to treat
acute asthmatic episodes. The other agents may reduce
the severity of attacks but not to the same degree or
consistency as fluticasone (or other corticosteroids).
A couple celebrating their fortieth wedding anniversary
is given a trip to Peru to visit Machu Picchu. Due
to past experiences while traveling, they ask their
doctor to prescribe an agent for diarrhea. Which of
the following would be effective?
A. Omeprazole.
B. Loperamide.
C. Famotidine.
D. Lorazepam.
7
A couple celebrating their fortieth wedding anniversary
is given a trip to Peru to visit Machu Picchu. Due
to past experiences while traveling, they ask their
doctor to prescribe an agent for diarrhea. Which of
the following would be effective?
A. Omeprazole.
B. Loperamide.
C. Famotidine.
D. Lorazepam.
7
Correct answer = B. Loperamide is the only drug in
this set that has antidiarrheal activity. Omeprazole
is a proton-pump inhibitor, famotidine antagonizes
the H2 receptor, and lorazepam is a benzodiazepine
that is a sedative and anxiolytic agent.
A 57-year-old man complains of fever, headache,
confusion, aversion to light, and neck rigidity. A
presumptive diagnosis of bacterial meningitis is made.
Antimicrobial therapy should be initiated after which
one of the following occurrences?
A. Fever is reduced with antipyretic drugs.
B. Sample of blood and cerebrospinal fluid have
been taken.
C. A Gram stain has been performed.
D. The results of antibacterial drug susceptibility
tests are available.
E. Infecting organism(s) have been identified by the
microbiology laboratory.
8
A 57-year-old man complains of fever, headache,
confusion, aversion to light, and neck rigidity. A
presumptive diagnosis of bacterial meningitis is made.
Antimicrobial therapy should be initiated after which
one of the following occurrences?
A. Fever is reduced with antipyretic drugs.
B. Sample of blood and cerebrospinal fluid have
been taken.
C. A Gram stain has been performed.
D. The results of antibacterial drug susceptibility
tests are available.
E. Infecting organism(s) have been identified by the
microbiology laboratory.
8
Correct answer = B. Bacterial meningitis is a medical
emergency that requires immediate diagnosis and
treatment. Specimens for possible microbial identification
must be obtained before drugs are administered.
Therapy should not be delayed until laboratory results are
available.
A 31-year-old white intravenous drug user was admitted
to the hospital with a 4-week history of cough
and fever. A chest radiograph showed left upper
lobe cavitary infiltrate. Cultures of sputum yielded
M. tuberculosis susceptible to all antimycobacterial
drugs. The patient received isoniazid, rifampin, and
pyrazinamide. The patient’s sputum remained culturepositive
for the subsequent 4 months. Which one of the
following is the most likely cause of treatment
failure?
A. False-positive cultures.
B. Maladsorption of the medications.
C. Concomitant infection with HIV.
D. Noncompliance by the
9
A 31-year-old white intravenous drug user was admitted
to the hospital with a 4-week history of cough
and fever. A chest radiograph showed left upper
lobe cavitary infiltrate. Cultures of sputum yielded
M. tuberculosis susceptible to all antimycobacterial
drugs. The patient received isoniazid, rifampin, and
pyrazinamide. The patient’s sputum remained culturepositive
for the subsequent 4 months. Which
one of the following is the most likely cause of treatment
failure?
A. False-positive cultures.
B. Maladsorption of the medications.
C. Concomitant infection with HIV.
D. Noncompliance by the patient.
9
Correct answer = D. Although malabsorption of the
drugs and the emergence of drug resistance are
possibilities, the most common cause of treatment
failure is patient‘s nonadherence to the treatment protocol.
Better treatment completion rates occur with “directly
observed therapy.” False-positive cultures is a
possible but unlikely explanation.
A soldier’s unit has come under attack with a nerve
agent. The symptoms exhibited are skeletal muscle
paralysis, profuse bronchial secretions, miosis,
bradycardia, and convulsions. The alarm indicates
exposure to an organophosphate.
What is the correct treatment?
A. Do nothing until you can confirm the nature of
the nerve agent.
B. Administer atropine, and attempt to confirm the
nature of the nerve agent.
C. Administer atropine and 2-PAM (pralidoxime).
D. Administer pralidoxime.
10
A soldier’s unit has come under attack with a nerve
agent. The symptoms exhibited are skeletal muscle
paralysis, profuse bronchial secretions, miosis,
bradycardia, and convulsions. The alarm indicates
exposure to an organophosphate. What is the correct
treatment?
A. Do nothing until you can confirm the nature of
the nerve agent.
B. Administer atropine, and attempt to confirm the
nature of the nerve agent.
C. Administer atropine and 2-PAM (pralidoxime).
D. Administer pralidoxime.
10
Correct answer = C. Organophosphates exert their
effect by irreversibly binding to acetylcholinesterase
(AChE) and, thus, can cause a cholinergic crisis.
Administration of atropine will block the muscarinic
sites, but it will not reactivate the enzyme, which will
remain blocked for a long period of time. Therefore,
it is essential to also administer pralidoxime as soon
as possible to reactivate the enzyme before aging
occurs. Administering pralidoxime alone will not
protect the patient against the effects of acetylcholine
resulting from AChE inhibition.
• Clark-Lippincott's, Illustrated Reviews – Pharmacology, 5th, 2012
• www.wikipedia.com