2026 AQUIFER INTERNAL MEDICINE END OF
CASE EXAM Questions with Correct Answers
& Rationales
Latest 2026 Update | 100% Verified | A+ Graded
Question 1
A 63-year-old male with no past medical history is hospitalized after a fall
and inability to care for himself at home. On his fourth day in the hospital,
he is transferred to the intensive care unit (ICU) for sepsis due to a urinary
tract infection (UTI). Which of the following would be the most appropriate
empiric antibiotic treatment for this patient?
A. Ampicillin and gentamicin
B. Azithromycin and trimethoprim-sulfamethoxazole
C. Ceftriaxone and cefepime
D. Ciprofloxacin and nitrofurantoin
E. Vancomycin and metronidazole
Correct Answer: A. Ampicillin and gentamicin
Rationale: Empiric antibiotics for sepsis due to UTI in a hospitalized patient
should cover both gram-negative and gram-positive organisms. Ampicillin
and gentamicin provide broad coverage, including Enterococcus and gram-
negative rods. From IM 21.
Question 2
A 36-year-old female without any past medical history presents to the
,emergency department with severe dehydration. Which of the following
urinalysis results would be most likely found in this patient?
A. Decreased urine sodium (Na), decreased fractional excretion of sodium
(FENa), increased urine osmolality
B. Decreased urine sodium (Na), increased FENa, decreased urine osmolality
C. Increased urine Na, decreased FENa, increased urine osmolality
D. Increased urine Na, increased FENa, decreased urine osmolality
Correct Answer: A. Decreased urine sodium (Na), decreased fractional
excretion of sodium (FENa), increased urine osmolality
Rationale: In prerenal azotemia from dehydration, the kidneys appropriately
conserve sodium and water. This results in low urine sodium (<20 mEq/L),
low FENa (<1%), and high urine osmolality (>500 mOsm/kg). From IM 21.
Question 3
A 49-year-old female presents to the emergency department with a one-
day history of bright-red blood per rectum. She reports no fevers,
abdominal pain, or lightheadedness. Her medical history is significant for
alcohol abuse and cirrhosis. She takes no medications. Her pulse is 90
beats/minute and blood pressure is 108/64 mmHg. On physical exam, she
has bilateral lower-extremity edema and ascites. After fluid resuscitation
and laboratory studies, which of the following is the most appropriate
diagnostic study?
A. Capsule endoscopy
B. Colonoscopy
C. Esophagogastroduodenoscopy (EGD)
D. Radionuclide imaging
E. Upper gastrointestinal (UGI) with small bowel follow-through
Correct Answer: B. Colonoscopy
,Rationale: In a patient with cirrhosis, hematochezia (bright red blood per
rectum) can be from lower GI sources or from massive upper GI bleeding with
rapid transit. However, colonoscopy is the initial diagnostic study of choice for
lower GI bleeding. From IM 21.
Question 4
A 28-year-old Caucasian female presents to the clinic for her annual exam.
She has no complaints. On exam, her pulse is 84 beats/minute, her blood
pressure is 116/70 mmHg, and her body mass index (BMI) is 28 kg/m².
Which of the following would prompt screening for diabetes?
A. A hemoglobin A1c (HbA1c) of 5 at last year's exam
B. A mother recently diagnosed with hypothyroidism
C. A paternal aunt with diabetes
D. A history of gestational diabetes with her last pregnancy, seven years
ago
E. Frequent consumption of refined carbohydrates
Correct Answer: D. A history of gestational diabetes with her last
pregnancy, seven years ago
Rationale: A history of gestational diabetes is a risk factor for developing type
2 diabetes and should prompt screening. The American Diabetes Association
recommends screening for diabetes in all adults with a BMI ≥25 kg/m² who
have one or more additional risk factors, including history of gestational
diabetes. From IM 07.
Question 5
A 23-year-old female with diabetes mellitus type 1, hypertension, and
hypothyroidism is admitted to the intensive care unit (ICU) with lethargy,
, nausea, and diarrhea. She is somnolent on admission; however, her
boyfriend provides some history. She has not taken her insulin for the past
three days due to nausea and vomiting, and she has had a poor appetite
and diarrhea. She is difficult to arouse. On exam, she is afebrile. She has no
other neurologic deficits. Her admission labs are shown: Sodium: 123
mEq/L, Potassium: 4.8 mEq/L, Chloride: 91 mEq/L, Bicarbonate (HCO₃): 10
mEq/L, Blood urea nitrogen (BUN): 48 mg/dL, Creatinine (Cr): 1.5 mg/dL,
Serum glucose: 540 mg/dL, White blood cell (WBC): 8 cells x 10³/μL, Serum
osmolality: 285 mosm/kg. Urinalysis is pending. What is the most likely
cause of her clinical presentation?
A. Diabetic ketoacidosis
B. Diarrhea
C. Pseudohyponatremia
D. Sepsis with lactic acidosis
E. Surreptitious consumption of isopropanol
Correct Answer: A. Diabetic ketoacidosis
Rationale: The patient has type 1 diabetes with insulin omission,
hyperglycemia (glucose 540 mg/dL), low bicarbonate (10 mEq/L), and an
anion gap metabolic acidosis. This is classic for diabetic ketoacidosis (DKA).
The serum osmolality of 285 mosm/kg suggests a mixed picture with
significant fluid shifts. From IM 07.
Question 6
An 82-year-old female with diabetes, hypertension, hyperlipidemia, and a
stroke three years ago with residual dysarthria is admitted to the intensive
care unit (ICU) after her daughter was unable to wake her up this morning.
On exam, she is afebrile, and her neurological exam is not focal. A head
computed tomography (CT) scan did not reveal any acute pathology. Labs
are as follows: white blood count (WBC) 12.4 cells x 10³/μL, sodium 123
mEq/L, potassium 3.4 mEq/L, chloride 107 mEq/L, bicarbonate 22 mEq/L,
CASE EXAM Questions with Correct Answers
& Rationales
Latest 2026 Update | 100% Verified | A+ Graded
Question 1
A 63-year-old male with no past medical history is hospitalized after a fall
and inability to care for himself at home. On his fourth day in the hospital,
he is transferred to the intensive care unit (ICU) for sepsis due to a urinary
tract infection (UTI). Which of the following would be the most appropriate
empiric antibiotic treatment for this patient?
A. Ampicillin and gentamicin
B. Azithromycin and trimethoprim-sulfamethoxazole
C. Ceftriaxone and cefepime
D. Ciprofloxacin and nitrofurantoin
E. Vancomycin and metronidazole
Correct Answer: A. Ampicillin and gentamicin
Rationale: Empiric antibiotics for sepsis due to UTI in a hospitalized patient
should cover both gram-negative and gram-positive organisms. Ampicillin
and gentamicin provide broad coverage, including Enterococcus and gram-
negative rods. From IM 21.
Question 2
A 36-year-old female without any past medical history presents to the
,emergency department with severe dehydration. Which of the following
urinalysis results would be most likely found in this patient?
A. Decreased urine sodium (Na), decreased fractional excretion of sodium
(FENa), increased urine osmolality
B. Decreased urine sodium (Na), increased FENa, decreased urine osmolality
C. Increased urine Na, decreased FENa, increased urine osmolality
D. Increased urine Na, increased FENa, decreased urine osmolality
Correct Answer: A. Decreased urine sodium (Na), decreased fractional
excretion of sodium (FENa), increased urine osmolality
Rationale: In prerenal azotemia from dehydration, the kidneys appropriately
conserve sodium and water. This results in low urine sodium (<20 mEq/L),
low FENa (<1%), and high urine osmolality (>500 mOsm/kg). From IM 21.
Question 3
A 49-year-old female presents to the emergency department with a one-
day history of bright-red blood per rectum. She reports no fevers,
abdominal pain, or lightheadedness. Her medical history is significant for
alcohol abuse and cirrhosis. She takes no medications. Her pulse is 90
beats/minute and blood pressure is 108/64 mmHg. On physical exam, she
has bilateral lower-extremity edema and ascites. After fluid resuscitation
and laboratory studies, which of the following is the most appropriate
diagnostic study?
A. Capsule endoscopy
B. Colonoscopy
C. Esophagogastroduodenoscopy (EGD)
D. Radionuclide imaging
E. Upper gastrointestinal (UGI) with small bowel follow-through
Correct Answer: B. Colonoscopy
,Rationale: In a patient with cirrhosis, hematochezia (bright red blood per
rectum) can be from lower GI sources or from massive upper GI bleeding with
rapid transit. However, colonoscopy is the initial diagnostic study of choice for
lower GI bleeding. From IM 21.
Question 4
A 28-year-old Caucasian female presents to the clinic for her annual exam.
She has no complaints. On exam, her pulse is 84 beats/minute, her blood
pressure is 116/70 mmHg, and her body mass index (BMI) is 28 kg/m².
Which of the following would prompt screening for diabetes?
A. A hemoglobin A1c (HbA1c) of 5 at last year's exam
B. A mother recently diagnosed with hypothyroidism
C. A paternal aunt with diabetes
D. A history of gestational diabetes with her last pregnancy, seven years
ago
E. Frequent consumption of refined carbohydrates
Correct Answer: D. A history of gestational diabetes with her last
pregnancy, seven years ago
Rationale: A history of gestational diabetes is a risk factor for developing type
2 diabetes and should prompt screening. The American Diabetes Association
recommends screening for diabetes in all adults with a BMI ≥25 kg/m² who
have one or more additional risk factors, including history of gestational
diabetes. From IM 07.
Question 5
A 23-year-old female with diabetes mellitus type 1, hypertension, and
hypothyroidism is admitted to the intensive care unit (ICU) with lethargy,
, nausea, and diarrhea. She is somnolent on admission; however, her
boyfriend provides some history. She has not taken her insulin for the past
three days due to nausea and vomiting, and she has had a poor appetite
and diarrhea. She is difficult to arouse. On exam, she is afebrile. She has no
other neurologic deficits. Her admission labs are shown: Sodium: 123
mEq/L, Potassium: 4.8 mEq/L, Chloride: 91 mEq/L, Bicarbonate (HCO₃): 10
mEq/L, Blood urea nitrogen (BUN): 48 mg/dL, Creatinine (Cr): 1.5 mg/dL,
Serum glucose: 540 mg/dL, White blood cell (WBC): 8 cells x 10³/μL, Serum
osmolality: 285 mosm/kg. Urinalysis is pending. What is the most likely
cause of her clinical presentation?
A. Diabetic ketoacidosis
B. Diarrhea
C. Pseudohyponatremia
D. Sepsis with lactic acidosis
E. Surreptitious consumption of isopropanol
Correct Answer: A. Diabetic ketoacidosis
Rationale: The patient has type 1 diabetes with insulin omission,
hyperglycemia (glucose 540 mg/dL), low bicarbonate (10 mEq/L), and an
anion gap metabolic acidosis. This is classic for diabetic ketoacidosis (DKA).
The serum osmolality of 285 mosm/kg suggests a mixed picture with
significant fluid shifts. From IM 07.
Question 6
An 82-year-old female with diabetes, hypertension, hyperlipidemia, and a
stroke three years ago with residual dysarthria is admitted to the intensive
care unit (ICU) after her daughter was unable to wake her up this morning.
On exam, she is afebrile, and her neurological exam is not focal. A head
computed tomography (CT) scan did not reveal any acute pathology. Labs
are as follows: white blood count (WBC) 12.4 cells x 10³/μL, sodium 123
mEq/L, potassium 3.4 mEq/L, chloride 107 mEq/L, bicarbonate 22 mEq/L,
