1|Page
NR 569 MIDTERM EXAM– DIFFERENTIAL DIAGNOSIS
IN ACUTE CARE PRACTICUM (MIDTERM REVIEW)
2026 ALL QUESTIONS AND CORRECT DETAILED
ANSWERS AND RATIONALES ALREADY A GRADED
WITH EXPERT FEEDBACK |NEW AND REVISED
1. A 68-year-old male presents to the emergency department with
acute onset chest pain. The ACNP begins generating diagnostic
hypotheses. Which approach best reflects the hypothesis-driven
method of diagnostic reasoning?
A. Order a comprehensive metabolic panel and wait for results before
forming any clinical impression
B. Generate multiple competing diagnoses simultaneously based on
the initial presentation, then systematically rule them in or out
C. Rely solely on pattern recognition from previous similar patients to
arrive at a single diagnosis immediately
D. Refer the patient to a specialist before initiating any diagnostic
workup given the complexity
The hypothesis-driven method involves generating multiple diagnostic
hypotheses early based on initial data, then systematically testing each
through focused assessment. This reduces cognitive bias and
anchoring, which are leading causes of diagnostic error in acute care.
Option A delays clinical reasoning inappropriately. Option C describes
pattern recognition, which is prone to bias with atypical presentations.
Option D defers reasoning without initial assessment by the ACNP.
2. An ACNP evaluates a 55-year-old female with dyspnea. The Wells
score estimates PE pre-test probability at 15%. A D-dimer returns
,2|Page
at 450 ng/mL (negative below 500). Using Bayesian analysis, what is
the most appropriate next step?
A. Discharge the patient since the negative D-dimer conclusively rules
out PE
B. Proceed directly to CTPA because the pre-test probability is too high
for D-dimer
C. Calculate post-test probability using the negative likelihood ratio
to determine if PE is excluded
D. Repeat the D-dimer in 24 hours to confirm the negative result before
disposition
Bayesian analysis requires combining pre-test probability with test
characteristics (likelihood ratios) to determine post-test probability.
The 2026 ACCP/ESC guidelines emphasize D-dimer interpretation
must integrate clinical probability via validated scoring. A D-dimer
near the cutoff with moderate pre-test probability does not
automatically exclude PE; the negative likelihood ratio must be
applied. If post-test probability remains above the test treatment
threshold, further imaging is warranted.
3. A 42-year-old female has 2 weeks of progressive fatigue, myalgias,
and low-grade fevers. She was diagnosed with viral syndrome 5 days
ago but now presents with new petechiae on her lower extremities
and gum bleeding. Which red flag most significantly changes
diagnostic urgency?
A. Duration of symptoms extending beyond 10 days without
improvement
B. New onset bleeding manifestations suggesting a potential
hematologic emergency
C. Presence of myalgias which could indicate an autoimmune process
D. Low-grade fevers suggesting an undiagnosed infectious etiology
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New onset petechiae and gum bleeding in a patient with constitutional
symptoms suggest a potential hematologic emergency such as
thrombocytopenia (e.g., ITP, TTP, DIC, or leukemia). These bleeding
manifestations dramatically increase diagnostic urgency and require
immediate CBC with platelet count and peripheral smear. The other
options, while clinically relevant, do not carry the same level of
immediacy.
4. A 45-year-old female presents with acute chest pain. The NP uses
the "most dangerous first" approach to differential diagnosis.
Which condition must be ruled out immediately before considering
less life-threatening causes?
A. Costochondritis
B. Gastroesophageal reflux disease
C. Acute coronary syndrome
D. Panic disorder
In acute chest pain, acute coronary syndrome (ACS) represents the
most dangerous differential and must be excluded first through ECG
and troponins before attributing symptoms to benign causes like
GERD or costochondritis. The "most dangerous first" approach
prioritizes life-threatening conditions to prevent catastrophic
outcomes.
5. A 62-year-old male with hypertension and hyperlipidemia
presents with acute-onset severe headache. The NP applies Bayesian
reasoning with a pretest probability of 15% for subarachnoid
hemorrhage. Which clinical feature most significantly increases the
post-test probability?
, 4|Page
A. Gradual onset over 2 hours
B. Pain relieved by acetaminophen
C. "Thunderclap" onset with meningismus
D. Bilateral frontal location
Thunderclap headache with meningismus is the classic presentation of
subarachnoid hemorrhage; this finding dramatically increases post-
test probability and mandates immediate non-contrast head CT. A
gradual onset and response to acetaminophen are more consistent
with benign etiologies. Bilateral frontal location is nonspecific.
6. A 38-year-old female presents with dyspnea and pleuritic chest
pain. The NP constructs a differential using the VINDICATE
mnemonic. Which condition represents the "I"
(inflammatory/infectious) category that is both common and
potentially life-threatening?
A. Pulmonary embolism
B. Pneumonia
C. Pneumothorax
D. Pericarditis
Pneumonia is an infectious/inflammatory cause of dyspnea and
pleuritic chest pain that is both common in acute care and potentially
life-threatening if severe or complicated by sepsis. In the VINDICATE
mnemonic: V = Vascular (PE), I = Infectious (pneumonia), N =
Neoplastic, D = Degenerative, I = Iatrogenic/Intoxication, C =
Congenital, A = Autoimmune, T = Traumatic, E =
Endocrine/Metabolic.
7. A 55-year-old male with diabetes mellitus presents with fever,
hypotension, and altered mental status. The NP prioritizes
NR 569 MIDTERM EXAM– DIFFERENTIAL DIAGNOSIS
IN ACUTE CARE PRACTICUM (MIDTERM REVIEW)
2026 ALL QUESTIONS AND CORRECT DETAILED
ANSWERS AND RATIONALES ALREADY A GRADED
WITH EXPERT FEEDBACK |NEW AND REVISED
1. A 68-year-old male presents to the emergency department with
acute onset chest pain. The ACNP begins generating diagnostic
hypotheses. Which approach best reflects the hypothesis-driven
method of diagnostic reasoning?
A. Order a comprehensive metabolic panel and wait for results before
forming any clinical impression
B. Generate multiple competing diagnoses simultaneously based on
the initial presentation, then systematically rule them in or out
C. Rely solely on pattern recognition from previous similar patients to
arrive at a single diagnosis immediately
D. Refer the patient to a specialist before initiating any diagnostic
workup given the complexity
The hypothesis-driven method involves generating multiple diagnostic
hypotheses early based on initial data, then systematically testing each
through focused assessment. This reduces cognitive bias and
anchoring, which are leading causes of diagnostic error in acute care.
Option A delays clinical reasoning inappropriately. Option C describes
pattern recognition, which is prone to bias with atypical presentations.
Option D defers reasoning without initial assessment by the ACNP.
2. An ACNP evaluates a 55-year-old female with dyspnea. The Wells
score estimates PE pre-test probability at 15%. A D-dimer returns
,2|Page
at 450 ng/mL (negative below 500). Using Bayesian analysis, what is
the most appropriate next step?
A. Discharge the patient since the negative D-dimer conclusively rules
out PE
B. Proceed directly to CTPA because the pre-test probability is too high
for D-dimer
C. Calculate post-test probability using the negative likelihood ratio
to determine if PE is excluded
D. Repeat the D-dimer in 24 hours to confirm the negative result before
disposition
Bayesian analysis requires combining pre-test probability with test
characteristics (likelihood ratios) to determine post-test probability.
The 2026 ACCP/ESC guidelines emphasize D-dimer interpretation
must integrate clinical probability via validated scoring. A D-dimer
near the cutoff with moderate pre-test probability does not
automatically exclude PE; the negative likelihood ratio must be
applied. If post-test probability remains above the test treatment
threshold, further imaging is warranted.
3. A 42-year-old female has 2 weeks of progressive fatigue, myalgias,
and low-grade fevers. She was diagnosed with viral syndrome 5 days
ago but now presents with new petechiae on her lower extremities
and gum bleeding. Which red flag most significantly changes
diagnostic urgency?
A. Duration of symptoms extending beyond 10 days without
improvement
B. New onset bleeding manifestations suggesting a potential
hematologic emergency
C. Presence of myalgias which could indicate an autoimmune process
D. Low-grade fevers suggesting an undiagnosed infectious etiology
,3|Page
New onset petechiae and gum bleeding in a patient with constitutional
symptoms suggest a potential hematologic emergency such as
thrombocytopenia (e.g., ITP, TTP, DIC, or leukemia). These bleeding
manifestations dramatically increase diagnostic urgency and require
immediate CBC with platelet count and peripheral smear. The other
options, while clinically relevant, do not carry the same level of
immediacy.
4. A 45-year-old female presents with acute chest pain. The NP uses
the "most dangerous first" approach to differential diagnosis.
Which condition must be ruled out immediately before considering
less life-threatening causes?
A. Costochondritis
B. Gastroesophageal reflux disease
C. Acute coronary syndrome
D. Panic disorder
In acute chest pain, acute coronary syndrome (ACS) represents the
most dangerous differential and must be excluded first through ECG
and troponins before attributing symptoms to benign causes like
GERD or costochondritis. The "most dangerous first" approach
prioritizes life-threatening conditions to prevent catastrophic
outcomes.
5. A 62-year-old male with hypertension and hyperlipidemia
presents with acute-onset severe headache. The NP applies Bayesian
reasoning with a pretest probability of 15% for subarachnoid
hemorrhage. Which clinical feature most significantly increases the
post-test probability?
, 4|Page
A. Gradual onset over 2 hours
B. Pain relieved by acetaminophen
C. "Thunderclap" onset with meningismus
D. Bilateral frontal location
Thunderclap headache with meningismus is the classic presentation of
subarachnoid hemorrhage; this finding dramatically increases post-
test probability and mandates immediate non-contrast head CT. A
gradual onset and response to acetaminophen are more consistent
with benign etiologies. Bilateral frontal location is nonspecific.
6. A 38-year-old female presents with dyspnea and pleuritic chest
pain. The NP constructs a differential using the VINDICATE
mnemonic. Which condition represents the "I"
(inflammatory/infectious) category that is both common and
potentially life-threatening?
A. Pulmonary embolism
B. Pneumonia
C. Pneumothorax
D. Pericarditis
Pneumonia is an infectious/inflammatory cause of dyspnea and
pleuritic chest pain that is both common in acute care and potentially
life-threatening if severe or complicated by sepsis. In the VINDICATE
mnemonic: V = Vascular (PE), I = Infectious (pneumonia), N =
Neoplastic, D = Degenerative, I = Iatrogenic/Intoxication, C =
Congenital, A = Autoimmune, T = Traumatic, E =
Endocrine/Metabolic.
7. A 55-year-old male with diabetes mellitus presents with fever,
hypotension, and altered mental status. The NP prioritizes
