Internal Medicine

A 74-year-old man is brought to the emergency department after experiencing three episodes of massive, painless hematochezia over the past two hours. His medical history is significant for coronary artery disease, hypertension, and osteoarthritis, for which he takes daily aspirin and naproxen. On arrival, he appears pale and diaphoretic. His temperature is 36.8°C (98.2°F), blood pressure is 84/52 mm Hg, pulse is 122/min, and respirations are 20/min. Abdominal examination is unremarkable with no tenderness or guarding. Rectal examination reveals copious amounts of bright red blood. Arrange the following steps in the most appropriate sequence for the evaluation and management of this patient's acute presentation.

A 62-year-old man with a history of alcohol-associated cirrhosis is brought to the emergency department due to progressive confusion, lethargy, and fever over the past 2 days. His temperature is $38.6^\circ\text{C}$ ($101.5^\circ\text{F}$), blood pressure is $95/60\text{ mm Hg}$, heart rate is $112/\text{min}$, and respiratory rate is $22/\text{min}$. Physical examination is notable for scleral icterus, spider angiomas, a distended abdomen with a positive fluid wave, and bilateral lower extremity pitting edema.

Laboratory studies show:
Sodium: $136\text{ mEq/L}$
Potassium: $3.8\text{ mEq/L}$
Chloride: $104\text{ mEq/L}$
Bicarbonate: $18\text{ mEq/L}$
BUN: $32\text{ mg/dL}$
Creatinine: $1.5\text{ mg/dL}$
Glucose: $98\text{ mg/dL}$
Albumin: $2.0\text{ g/dL}$
Total bilirubin: $4.5\text{ mg/dL}$

Arterial blood gas on room air reveals a pH of $7.32$ and a $PaCO_2$ of $34\text{ mm Hg}$.

Assuming a reference normal serum albumin of $4.0\text{ g/dL}$, what is this patient's albumin-corrected serum anion gap in mEq/L?

A $62$-year-old man presents to the emergency department with a $3$-day history of worsening left lower quadrant abdominal pain, fever, and anorexia. His temperature is $38.8^\circ\text{C}$ ($101.8^\circ\text{F}$), blood pressure is $122/78\text{ mm Hg}$, and pulse is $102/\text{min}$. Physical examination demonstrates significant focal tenderness and guarding in the left lower quadrant without diffuse peritonitis. Laboratory testing shows a leukocyte count of $17,200/\text{mm}^3$ with a left shift. Empiric broad-spectrum intravenous antibiotics are initiated immediately. Assuming the initial diagnostic imaging confirms acute complicated diverticulitis with a $5\text{ cm}$ pericolic abscess, arrange the following management steps in the most appropriate chronological sequence.

A 64-year-old woman presents to the emergency department with a 3-day history of progressively worsening shortness of breath and a dry cough. She has a 35-pack-year smoking history and a history of an anterior myocardial infarction 4 years ago. On physical examination, her blood pressure is 155/90 mmHg, heart rate is 102/min, and respiratory rate is 22/min. Oxygen saturation is 89% on room air. Lung auscultation reveals diffuse expiratory wheezes bilaterally and prolonged expiration. Cardiac auscultation reveals a regular rhythm with an audible S3 gallop. She has 2+ pitting edema in both lower extremities. Which of the following laboratory findings is most useful to differentiate the primary cause of this patient's respiratory symptoms from a chronic obstructive pulmonary disease (COPD) exacerbation?

A $68$-year-old man is evaluated for a $3$-week history of unexplained weight loss, heat intolerance, and resting tremor. He has a history of refractory paroxysmal atrial fibrillation, for which he has been receiving amiodarone and apixaban therapy over the last $3$ years. His temperature is $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), blood pressure is $142/84\text{ mmHg}$, and pulse is $114/\text{min}$ and irregularly irregular. Physical examination is notable for a fine tremor in the outstretched hands. The thyroid gland is not enlarged, and no nodules are palpated. Laboratory tests are obtained:

A color Doppler ultrasonography of the neck shows a structurally normal thyroid gland with markedly decreased vascular flow. Which of the following is the most appropriate targeted therapy for this patient's thyroid abnormality?

A 22-year-old woman with a history of type 1 diabetes mellitus is brought to the emergency department due to a 2-day history of worsening nausea, vomiting, and diffuse abdominal pain. She recently had an upper respiratory tract infection and missed several doses of her basal insulin. Her temperature is 37.4°C (99.3°F), blood pressure is 92/60 mm Hg, pulse is 124/min, and respirations are 28/min and deep. Her mucous membranes are dry. Initial laboratory results show:

Arrange the following interventions in the most appropriate chronological sequence for the management of this patient's condition, from initial presentation in the emergency department to the resolution of the acute crisis.

A $67$-year-old man comes to the clinic reporting progressive difficulty swallowing over the past four months. Initially, he noticed food feeling "stuck" in his lower chest when eating solid meals such as meat, but recently he has struggled to swallow liquids as well. He notes an unintentional weight loss of $11$ kg ($24$ lbs) since his symptoms began. His medical history is notable for hypertension, hyperlipidemia, and a $45$-pack-year smoking history. Vital signs are within normal limits. Physical examination reveals temporal wasting but is otherwise unremarkable. Laboratory studies show a hemoglobin of $10.2$ g/dL with a mean corpuscular volume of $76$ fL. Based on current clinical guidelines, arrange the following diagnostic and staging steps in the most appropriate chronological order.

A 62-year-old man presents with severe substernal chest pain. He is diagnosed with an acute ST-segment elevation myocardial infarction (STEMI). In the absence of immediate reperfusion therapy, electrocardiographic (ECG) changes in the affected leads typically evolve in a predictable chronological sequence. Arrange the following classic ECG findings in the chronological order of their appearance, from earliest to latest.

Match the following diagnostic laboratory profiles of calcium and phosphate homeostasis to their most likely underlying pathophysiologic etiology. Assume all patients have normal serum albumin and normal magnesium levels unless otherwise indicated.

A $35$-year-old woman comes to the clinic due to a $3$-month history of constant anxiety, excessive sweating, unintended weight loss of $4.5$ kg ($10$ lb), and frequent heart palpitations. She has no significant past medical history and takes no medications. Vital signs show a blood pressure of $138/78$ mm Hg and a heart rate of $114/min$. Physical examination reveals a fine resting tremor in both hands, warm and diaphoretic skin, and a symmetrically enlarged, non-tender thyroid gland. There is no proptosis, extraocular muscle restriction, or pretibial myxedema.

Laboratory studies reveal:
Thyroid-stimulating hormone (TSH): $6.2 \mu U/mL$ (Normal: $0.4-4.0 \mu U/mL$)
Free thyroxine (T4): $3.4 ng/dL$ (Normal: $0.9-2.4 ng/dL$)
Total triiodothyronine (T3): $270 ng/dL$ (Normal: $80-200 ng/dL$)
Urine human chorionic gonadotropin: Negative

Which of the following is the most appropriate next step in the evaluation of this patient?

A $41$-year-old man is evaluated in the hospital on the third day of his admission for community-acquired pneumonia. He initially presented with a two-day history of high fever, productive cough, and right-sided pleuritic chest pain. On admission, his temperature was $38.8^\circ\text{C}$ ($101.8^\circ\text{F}$), blood pressure was $118/74\text{ mm Hg}$, pulse was $110\text{/min}$, and respirations were $24\text{/min}$. Chest radiography showed a right lower lobe consolidation. He was subsequently started on empiric intravenous levofloxacin.

Today, the patient reports feeling significantly better. He has been afebrile for the past $24\text{ hours}$, and his cough has improved. Current vital signs are temperature $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure $122/78\text{ mm Hg}$, pulse $82\text{/min}$, and respirations $16\text{/min}$. He is tolerating a regular diet.

Blood cultures drawn on admission are now positive for Streptococcus pneumoniae. Susceptibility testing of the isolate demonstrates the following:

Which of the following is the most appropriate next step in pharmacotherapy?

A 62-year-old man is brought to the emergency department via ambulance due to the sudden onset of severe, excruciating chest pain that radiates to his interscapular region. Shortly after the pain began, he developed severe shortness of breath. His medical history is significant for poorly controlled hypertension, tobacco use, and chronic obstructive pulmonary disease. On arrival, his blood pressure is 185/105 mmHg in the right arm and 178/100 mmHg in the left arm. His pulse is 118/min, and his respiratory rate is 28/min with an oxygen saturation of 88% on room air. Physical examination reveals a diaphoretic man in severe respiratory distress. Lung auscultation demonstrates diffuse bilateral expiratory wheezing with crackles at the lung bases. Cardiovascular examination reveals a new decrescendo diastolic murmur loudest at the right upper sternal border. An electrocardiogram shows sinus tachycardia with left ventricular hypertrophy. Which of the following is the most appropriate initial pharmacological step in the management of this patient?

A rapid response team is called to the bedside of a $72$-year-old woman who was admitted two days ago for community-acquired pneumonia and a suspected exacerbation of chronic obstructive pulmonary disease (COPD). Her medical history includes tobacco use disorder, type 2 diabetes mellitus, and a prior anterior myocardial infarction. Initial management included intravenous ceftriaxone, azithromycin, inhaled bronchodilators, and systemic glucocorticoids. Sputum cultures obtained on admission are now growing *Streptococcus pneumoniae* that is susceptible to penicillin.

Over the past $4$ hours, the patient has developed sudden, severe respiratory distress. Her temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $182/104$ mm Hg, pulse is $115$/min, and respirations are $28$/min. Pulse oximetry shows $86\%$ on room air. Physical examination reveals jugular venous distention to $11$ cm H $_2$ O. Chest auscultation reveals prolonged expiration with diffuse bilateral wheezing. Cardiac auscultation shows a regular tachycardia without murmurs. Point-of-care ultrasound of the lungs demonstrates diffuse bilateral B-lines.

Laboratory studies show:
Serum sodium: $138$ mEq/L
Serum potassium: $4.2$ mEq/L
Serum chloride: $104$ mEq/L
Serum bicarbonate: $16$ mEq/L
Serum creatinine: $1.6$ mg/dL

Thyroid-stimulating hormone (TSH): $1.2$ mIU/L (N: $0.4 - 4.0$ mIU/L)
Free T4: $0.7$ ng/dL (N: $0.9 - 1.7$ ng/dL)

Arterial blood gas (room air):
pH: $7.30$
PaCO $_2$: $32$ mm Hg
PaO $_2$: $58$ mm Hg

Which of the following is the most appropriate next step in management?

A $62$-year-old woman with a history of type 2 diabetes mellitus is evaluated on hospital day $6$ for management of a pyogenic liver abscess. She originally presented with high fever, malaise, and severe right upper quadrant abdominal pain. Imaging on admission revealed a $5\text{-cm}$ thick-walled fluid collection in the right hepatic lobe. She was started on empiric intravenous piperacillin-tazobactam, and a percutaneous drain was placed by interventional radiology.

The patient's clinical status has significantly improved. She has been afebrile for $72$ hours, and her leukocyte count has decreased from $18,000/\mu\text{L}$ to $9,500/\mu\text{L}$. The percutaneous drain output has been less than $15\text{ mL}$ over the last $24$ hours. Abscess fluid cultures drawn during placement show pure growth of *Klebsiella pneumoniae*. Susceptibility testing demonstrates the organism is susceptible to ceftriaxone, ciprofloxacin, and piperacillin-tazobactam, but resistant to ampicillin.

Which of the following is the most appropriate next step in management?

An $81$-year-old male is transferred to the intensive care unit due to rapid clinical deterioration. He was initially admitted to the general medical ward six days ago for an acute exacerbation of chronic obstructive pulmonary disease and was appropriately treated with systemic glucocorticoids and levofloxacin. On his fourth day of hospitalization, he developed profuse, watery stools and diffuse abdominal cramping. Stool assays returned positive for *Clostridioides difficile* toxins A and B, prompting the initiation of oral vancomycin. Today, he is increasingly lethargic and minimally responsive. His temperature is $39.4^\circ\text{C}$ ($102.9^\circ\text{F}$), blood pressure is $82/50\text{ mmHg}$, pulse is $128/\text{min}$, and respiratory rate is $28/\text{min}$. Physical examination reveals a markedly distended, tympanitic abdomen with severe generalized tenderness, rebound guarding, and absent bowel sounds.

Laboratory analysis reveals:
* Leukocytes: $38,000/\text{mm}^3$
* Serum bicarbonate: $10\text{ mEq/L}$
* Arterial blood gas (room air): pH $7.22$, pCO2 $24\text{ mmHg}$, pO2 $68\text{ mmHg}$

A supine abdominal radiograph demonstrates a transverse colon diameter of $8.5\text{ cm}$ with distinct loss of haustral markings, thumbprinting, and no evidence of pneumoperitoneum. After initiating aggressive fluid resuscitation, which of the following is the most appropriate next step in the management of this patient?

A 28-year-old woman presents to the emergency department complaining of a sudden onset of rapid heart palpitations and mild chest fullness that began 30 minutes ago while she was watching television. She denies any chest pain, lightheadedness, or loss of consciousness. Her vital signs are temperature 37.0°C (98.6°F), blood pressure 118/76 mmHg, heart rate 175/min, and respiratory rate 16/min. Physical examination reveals a rapid, regular pulse and clear lungs. A 12-lead electrocardiogram (ECG) demonstrates a regular, narrow-complex tachycardia at a rate of 175/min with no discernible P waves.

Arrange the following therapeutic interventions in the most appropriate chronological sequence for the acute and definitive management of this condition, assuming each preceding step is ineffective.

Match each detailed clinical description of a cardiac murmur and its response to dynamic physiological maneuvers with the correct underlying structural pathology.

A 68-year-old man is evaluated in the intensive care unit for decreased urine output. He was admitted 4 days ago for septic shock secondary to severe community-acquired pneumonia and initially required norepinephrine for blood pressure support. He has been hemodynamically stable off vasopressors for the past 24 hours. His current blood pressure is 118/76 mm Hg and heart rate is 82/min. Laboratory studies show:

Serum sodium: 140 mEq/L
Serum blood urea nitrogen (BUN): 32 mg/dL
Serum creatinine: 2.0 mg/dL

Urine sodium: 63 mEq/L
Urine creatinine: 30 mg/dL

Urinalysis reveals muddy brown granular casts.

Calculate the patient's fractional excretion of sodium (FeNa). (Express the result as a percentage)

Match each classic peripheral arterial pulse abnormality with its most commonly associated cardiovascular pathology.

A 42-year-old man presents to the outpatient clinic reporting episodic severe headaches, profound diaphoresis, and a sensation of a racing heart over the past three months. His blood pressure is 175/105 mm Hg, and his pulse is 110/min. Laboratory evaluation reveals markedly elevated 24-hour urine fractionated metanephrines and catecholamines. An abdominal magnetic resonance imaging (MRI) scan demonstrates a 4.5-cm right adrenal mass. The patient is diagnosed with a pheochromocytoma and is scheduled for definitive surgical resection. Arrange the following preoperative management steps in the correct chronological order to prepare this patient safely for surgery.