Internal Medicine

A 55-year-old woman with a recent diagnosis of advanced non-small cell lung cancer is brought to the emergency department due to worsening shortness of breath, profound weakness, and lightheadedness over the past 48 hours. On physical examination, she is diaphoretic and in moderate respiratory distress. Her blood pressure is 82/60 mmHg, heart rate is 118/min, and respiratory rate is 24/min. Jugular venous pressure is estimated at 14 cm H₂O. Auscultation reveals distant heart sounds and clear lung fields bilaterally. Her systolic blood pressure decreases by 18 mmHg during inspiration.

Arrange the following diagnostic and management steps in the most appropriate chronological order for this patient.

A $47$-year-old man with a history of ulcerative colitis, chronic obstructive pulmonary disease (COPD), and hypothyroidism is evaluated in the intensive care unit. He was admitted $2$ days ago for a severe ulcerative colitis flare characterized by $>10$ bloody bowel movements per day and was started on intravenous methylprednisolone. Over the past $12$ hours, his diarrhea has abruptly ceased, but he has developed severe, diffuse abdominal pain and progressive distension.

Vital signs:
- Temperature: $39.3^\circ\text{C}$ ($102.7^\circ\text{F}$)
- Blood pressure: $84/52 \text{ mm Hg}$
- Heart rate: $136/\text{min}$
- Respiratory rate: $28/\text{min}$

Physical examination reveals a markedly distended abdomen with diffuse rebound tenderness and rigidity. Bowel sounds are absent. Lung auscultation reveals faint, scattered expiratory wheezes bilaterally.

Laboratory studies:
- Leukocytes: $25,500/\text{mm}^3$
- Bicarbonate: $13 \text{ mEq/L}$
- Arterial blood gas (on room air): pH $7.24$, $PaCO_2$ $30 \text{ mm Hg}$, $PaO_2$ $68 \text{ mm Hg}$
- TSH: $0.1 \mu\text{U/mL}$ (Normal: $0.4$-$4.0$)
- Free T4: $0.5 \text{ ng/dL}$ (Normal: $0.9$-$1.7$)
- Lactic acid: $7.2 \text{ mmol/L}$ (Normal: $0.5$-$2.2$)

An upright abdominal radiograph shows a continuous column of gas in the transverse colon measuring $8.5 \text{ cm}$ in diameter with a loss of normal haustral markings. No free air under the diaphragm is visualized.

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

A 34-year-old woman presents to the clinic with progressive weight gain, easy bruising, and new-onset facial hair growth over the past year. Examination reveals facial plethora, central adiposity, proximal muscle weakness, and wide purple striae on her abdomen. Her blood pressure is 155/95 mmHg. Arrange the following diagnostic steps in the correct sequential order for the evaluation of this patient's suspected hypercortisolism.

Match each physical examination finding describing a characteristic cardiac murmur to the most likely underlying cardiovascular condition or pathology.

A 60-year-old man is brought to the emergency department due to sudden-onset, severe, diffuse abdominal pain that began 2 hours ago. He has a history of severe osteoarthritis for which he takes high-dose ibuprofen daily. On physical examination, he appears in significant distress and lies completely still on the stretcher. Vital signs show a temperature of 38.2°C (100.8°F), heart rate of 115/min, and blood pressure of 98/60 mm Hg. Abdominal examination reveals a rigid, board-like abdomen with diffuse rebound tenderness and involuntary guarding. Arrange the following steps in the most appropriate chronological order for the management of this patient's condition.

A resident is evaluating four patients who all present with significant hypokalemia and metabolic alkalosis. Pair each patient's specific clinical and laboratory profile with the most likely underlying etiology.

A $29$-year-old woman is evaluated on the medical ward on hospital day $3$ for acute pyelonephritis. On admission, she reported a $2$-day history of high fever, dysuria, and severe right-sided back pain. She works as a nurse and has a history of recurrent urinary tract infections. Due to local antibiogram data showing high rates of fluoroquinolone resistance and her recent healthcare exposure, she was started empirically on intravenous piperacillin-tazobactam. The patient has improved significantly; she has been afebrile for $24$ hours, her flank pain is minimal, and she is tolerating oral intake perfectly. Her temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $112/70\text{ mm Hg}$, and pulse is $76/\text{min}$. Final urine culture results from admission demonstrate $>100,000$ colony-forming units/mL of *Klebsiella pneumoniae*. Susceptibility testing shows the isolate is resistant to ampicillin, but sensitive to ceftriaxone, cefazolin, ciprofloxacin, and piperacillin-tazobactam. Which of the following is the most appropriate next step in management?

A $65$-year-old man is evaluated in the emergency department for severe, unremitting abdominal pain that began abruptly $6$ hours ago. Earlier in the day, he experienced nausea, bilious vomiting, and abdominal bloating. He has not passed flatus or stool for the last $24$ hours. His medical history is significant for an open appendectomy $20$ years ago and essential hypertension. Vital signs are temperature $38.8^\circ\text{C}$ ($101.8^\circ\text{F}$), blood pressure $90/60 \text{ mmHg}$, heart rate $118/\text{min}$, and respiratory rate $22/\text{min}$. Physical examination reveals a distended abdomen with absent bowel sounds. There is significant tenderness to palpation in the right lower quadrant, accompanied by involuntary guarding and rebound tenderness. Laboratory studies show a leukocyte count of $18,500/\text{mm}^3$ and a serum bicarbonate of $14 \text{ mEq/L}$. An arterial blood gas analysis on room air reveals a pH of $7.28$ and a $\text{PaCO}_2$ of $30 \text{ mmHg}$. An upright abdominal radiograph demonstrates multiple dilated small bowel loops with air-fluid levels and a paucity of colonic gas. Which of the following is the most appropriate next step in the management of this patient?

A 62-year-old man is evaluated in the cardiac intensive care unit following an acute anterior myocardial infarction. On hospital day 2, the telemetry monitor suddenly alarms, demonstrating a chaotic, irregular rhythm with an undulating baseline and no discernible P waves, QRS complexes, or T waves. The patient is found unresponsive, apneic, and pulseless. The emergency response team arrives immediately with a defibrillator, and chest compressions are initiated. Arrange the following subsequent interventions in the most appropriate chronological sequence according to standard Advanced Cardiovascular Life Support (ACLS) guidelines for this presentation.

Match each patient presentation and history of infective endocarditis to the most likely causative organism.

Match each hepatobiliary disorder with its most characteristic histopathologic finding on liver biopsy.

A 69-year-old man comes to the emergency department reporting a two-week history of progressive abdominal bloating, right-sided abdominal pain, and swelling in both legs. He also reports worsening shortness of breath over the past six months, noting that he now has to stop and rest after walking just one block. He has a 50-pack-year smoking history and has not received routine medical care for over a decade. He does not take any medications.

Vital signs are temperature 37.0°C (98.6°F), blood pressure 110/70 mm Hg, pulse 95/min, and respirations 22/min. Pulse oximetry shows 85% on room air.

Physical examination shows central cyanosis. The jugular venous pressure is estimated at 14 cm H2O. The anteroposterior diameter of the chest is increased. Lung auscultation reveals globally diminished breath sounds and a prolonged expiratory phase, with no crackles or wheezes. Cardiac examination demonstrates a prominent parasternal lift and an accentuated pulmonic component of the second heart sound. A high-pitched, holosystolic murmur is heard at the left lower sternal border; the intensity of the murmur increases during inspiration. The abdomen is distended; the liver is palpable 5 cm below the right costal margin and is pulsatile. There is 3+ pitting edema of the lower extremities bilaterally.

Initial laboratory studies show:
Hemoglobin: $18.2 \text{ g/dL}$
Leukocyte count: $8,500/\text{mm}^3$
Platelet count: $210,000/\text{mm}^3$
Brain natriuretic peptide (BNP): $420 \text{ pg/mL}$

Arterial blood gas analysis on room air:
$\text{pH}$: $7.37$
$\text{PaCO}_2$: $54 \text{ mm Hg}$
$\text{PaO}_2$: $52 \text{ mm Hg}$
$\text{HCO}_3^-$: $30 \text{ mEq/L}$

A chest radiograph shows hyperlucent lung fields, flattened hemidiaphragms, and prominent central pulmonary arteries without pulmonary venous congestion or pleural effusions.

Which of the following therapies is most likely to improve long-term survival in this patient?

A 45-year-old man is evaluated in the emergency department for a 3-day history of intractable nausea, nonbilious vomiting, and diffuse abdominal pain. He has a known history of severe alcohol use disorder and reports his last alcoholic beverage was approximately 48 hours ago. On physical examination, he appears agitated, diaphoretic, and tremulous.

Vital signs are:
Temperature: $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$)
Blood pressure: $105/65\text{ mm Hg}$
Heart rate: $115/\text{min}$
Respiratory rate: $26/\text{min}$

Urinalysis is strongly positive for ketones.

Based on these findings, which of the following best describes this patient's acid-base disorder?

Evaluation for chronic palpitations and unintentional weight loss brings a 25-year-old female fitness instructor to the outpatient clinic. She reports feeling excessively warm even in air-conditioned environments and describes a $5$-kg ($11$-lb) weight loss over the past 2 months despite a notably increased appetite. Vital signs reveal a pulse of $112$/min and a blood pressure of $138/78$ mmHg. Physical examination shows a fine resting tremor of the outstretched hands, hyperreflexia, and warm, moist skin. The thyroid gland is non-palpable, and there is no evidence of exophthalmos or pretibial myxedema. A urine pregnancy test is negative.

Initial laboratory investigations demonstrate the following:
Thyroid-stimulating hormone (TSH): $0.02 \mu$ U/mL (Reference: $0.4–4.0 \mu$ U/mL)
Free thyroxine ($T_4$): $0.5$ ng/dL (Reference: $0.8–1.8$ ng/dL)

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

A 69-year-old man is brought to the emergency department at 3:00 AM due to severe shortness of breath that awoke him from sleep. The patient states he has been feeling increasingly fatigued over the past 3 days and has noticed swelling in both of his lower legs. His past medical history includes hypertension, hyperlipidemia, and a 45-pack-year smoking history. He admits to poor adherence to his prescribed daily medications. On arrival, his temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $172/96\text{ mmHg}$, pulse is $115/\text{min}$, and respiratory rate is $26/\text{min}$. Pulse oximetry shows $89\%$ on room air. Physical examination reveals a patient in moderate respiratory distress, sitting upright on the edge of the stretcher. The jugular venous pressure is visibly elevated to $11\text{ cm H}_2\text{O}$. Lung auscultation demonstrates diffuse expiratory wheezes and prominent bibasilar crackles. Cardiac examination reveals a tachycardic, regular rhythm with a third heart sound ($S_3$). There is 2+ pitting edema extending up to the knees bilaterally. Which of the following is the most appropriate initial pharmacologic therapy for this patient?

A 42-year-old man is brought to the emergency department by his friends due to unresponsiveness. They report that he consumed a large amount of alcohol at a party before becoming stuporous and vomiting profusely. On initial arrival, the patient is difficult to arouse but is protecting his airway. His vital signs are stable, and he is placed in a lateral decubitus position for observation. Two hours later, he develops sudden respiratory distress. Temperature is $37.9^\circ\text{C}$ ($100.2^\circ\text{F}$), blood pressure is $130/80\text{ mmHg}$, pulse is $110\text{/min}$, and respirations are $26\text{/min}$. Pulse oximetry shows an oxygen saturation of $88\%$ on room air. Physical examination reveals diminished breath sounds and crackles in the right lower lung field. Leukocyte count is $14,500/\mu\text{L}$. A chest radiograph demonstrates patchy alveolar opacities in the right lower lobe. Which of the following is the most appropriate next step in management?

Match each clinical vignette describing a patient with an endocrine or renal-related blood pressure/electrolyte abnormality to their expected pathophysiologic laboratory profile.

A 45-year-old man is evaluated in the surgical intensive care unit on postoperative day 1 following an exploratory laparotomy and necrosectomy for severe acute pancreatitis. Over the past 4 hours, he has developed worsening dyspnea and hypoxemia. His temperature is $38.5^\circ\text{C}$ ($101.3^\circ\text{F}$), blood pressure is 112/72 mm Hg, pulse is 118/min, and respirations are 32/min. Oxygen saturation is 84% despite receiving 100% oxygen via a non-rebreather mask. Physical examination reveals diffuse bilateral crackles on lung auscultation. Jugular venous pressure is 6 cm H $_2$ O. A portable chest radiograph demonstrates new bilateral alveolar opacities with a normal cardiac silhouette. A bedside echocardiogram shows a normal left ventricular ejection fraction and no significant valvular disease.

The patient is endotracheally intubated and placed on mechanical ventilation. Initial arterial blood gas analysis reveals:
pH: $7.36$
PaCO $_2$: $40 \text{ mm Hg}$
PaO $_2$: $54 \text{ mm Hg}$
HCO $_3^-$: $22 \text{ mEq/L}$

Current ventilator settings are:
Mode: Volume assist-control
Tidal volume: 8 mL/kg of predicted body weight
Respiratory rate: 14/min
Fraction of inspired oxygen (FiO $_2$): 0.80
Positive end-expiratory pressure (PEEP): 5 cm H $_2$ O

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

A $28$-year-old woman with a history of type 1 diabetes mellitus presents to the hospital after $4$ days of worsening abdominal pain, severe nausea, and frequent episodes of nonbilious vomiting. She has missed several doses of her basal insulin due to her inability to tolerate oral intake. On arrival, her blood pressure is $98/62 \text{ mm Hg}$, and her pulse is $115/\text{min}$. Physical examination reveals significantly dry mucous membranes, decreased skin turgor, and diffuse mild abdominal tenderness without rebound or guarding.

Laboratory values are as follows:

Serum sodium: $138 \text{ mEq/L}$
Serum potassium: $4.8 \text{ mEq/L}$
Serum chloride: $92 \text{ mEq/L}$
Serum bicarbonate: $14 \text{ mEq/L}$
Arterial pH: $7.28$
Arterial $PaCO_2$: $29 \text{ mm Hg}$

Assume a normal baseline anion gap of $12 \text{ mEq/L}$.

What is the patient's calculated corrected bicarbonate level in $\text{mEq/L}$?

A $68$-year-old woman with a history of poorly controlled type $2$ diabetes mellitus is evaluated on hospital day $3$. She originally presented to the emergency department with fever, right upper quadrant abdominal pain, and jaundice. On admission, her temperature was $39.2^{\circ}\text{C}$ ($102.6^{\circ}\text{F}$), blood pressure was $88/54\text{ mmHg}$, and heart rate was $118/\text{min}$. Laboratory studies showed a leukocyte count of $21,000/\mu\text{L}$, total bilirubin of $6.4\text{ mg/dL}$, and alkaline phosphatase of $450\text{ U/L}$. Blood cultures were drawn, and she was aggressively resuscitated with intravenous fluids and empiric intravenous piperacillin-tazobactam.

She subsequently underwent an emergent endoscopic retrograde cholangiopancreatography (ERCP), which revealed a common bile duct stone. A biliary sphincterotomy was performed, and the stone was successfully extracted, followed by the placement of a biliary stent.

Today, the patient is afebrile and hemodynamically stable. Her abdominal pain has resolved, and she is tolerating a regular diet. Her leukocyte count has decreased to $9,000/\mu\text{L}$. The admission blood cultures have grown *Escherichia coli*. The susceptibility report indicates the organism is sensitive to ampicillin, ceftriaxone, ciprofloxacin, and piperacillin-tazobactam.

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