Internal Medicine

During an overnight shift in the emergency department, a $73$-year-old woman is evaluated for severe, acute-onset respiratory distress. She reports waking up abruptly with a choking sensation and an inability to catch her breath. Her medical history includes chronic obstructive pulmonary disease, hypertension, and type 2 diabetes mellitus. Her home medications include amlodipine, metformin, and a tiotropium inhaler. Her temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $182/104\text{ mm Hg}$, pulse is $115\text{/min}$ and regular, and respirations are $28\text{/min}$. Pulse oximetry shows an oxygen saturation of $86\%$ on room air. The patient is visibly anxious, diaphoretic, and speaking in short phrases. Jugular venous pressure is estimated at $10\text{ cm H}_2\text{O}$. Chest auscultation reveals diffuse, bilateral expiratory wheezes and prominent fine crackles in the lower lung fields. Cardiac examination demonstrates a normal $S_1$ and $S_2$ with an audible $S_3$ gallop. Trace bilateral pitting edema is present at the ankles. Which of the following is the most appropriate initial pharmacotherapy for this patient?

A $62$-year-old man is evaluated in the emergency department for severe abdominal pain and recurrent vomiting. Over the past $48$ hours, he experienced crampy, intermittent periumbilical pain, but it abruptly changed to a severe, unremitting ache $4$ hours ago. His last bowel movement was $3$ days ago, and he has not passed flatus since the symptoms began. His surgical history is notable for an appendectomy via a lower midline incision $20$ years ago. Temperature is $38.9^\circ\text{C}$ ($102.0^\circ\text{F}$), pulse is $124/\text{min}$, respirations are $22/\text{min}$, and blood pressure is $96/60\text{ mmHg}$. Physical examination reveals a markedly distended abdomen. Bowel sounds are absent. There is diffuse rigidity, and severe focal tenderness with involuntary guarding is elicited in the mid-abdomen. Laboratory studies reveal a leukocyte count of $18,500/\text{mm}^3$ with $12\%$ bands. Venous blood gas shows a pH of $7.28$ and a bicarbonate level of $15\text{ mEq/L}$. Which of the following is the most appropriate next step in management?

An obtunded $71$-year-old man is evaluated in the emergency department for acute, severe dyspnea and altered mental status. He has a past medical history of ischemic cardiomyopathy with a left ventricular ejection fraction of $35\%$, severe chronic obstructive pulmonary disease, and type 2 diabetes mellitus. He was evaluated at an outpatient clinic two days ago for a mild cough; a sputum culture from that visit is now resulting, showing *Haemophilus influenzae* susceptible to amoxicillin. The patient is accompanied by his estranged wife and his brother. The brother provides a legally binding document designating him as the patient's healthcare proxy. The wife demands that the patient be placed on a mechanical ventilator immediately, while the brother requests that medical therapies be optimized first before considering intubation.

Vital signs include a temperature of $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure of $82/55\text{ mm Hg}$, pulse of $118/\text{min}$, and respirations of $28/\text{min}$. Oxygen saturation is $88\%$ on room air. Physical examination reveals a somnolent but arousable patient. The extremities are cool and clammy with faint peripheral pulses. Jugular venous pressure is elevated to $13\text{ cm H}_2\text{O}$. Lung auscultation demonstrates diffuse, high-pitched expiratory wheezes bilaterally without crackles. Cardiac auscultation reveals distant heart sounds with a regular tachycardia.

Laboratory results are as follows:
Leukocyte count: $11,500/\mu\text{L}$
Lactic acid: $4.8\text{ mmol/L}$
Thyroid-stimulating hormone: $1.2\text{ }\mu\text{U/mL}$ (Normal: $0.4-4.0\text{ }\mu\text{U/mL}$)
Free T4: $0.6\text{ ng/dL}$ (Normal: $0.9-1.7\text{ ng/dL}$)

A chest radiograph reveals an enlarged cardiac silhouette with prominent upper lobe vasculature and no focal consolidations. Which of the following is the most appropriate next step in the management of this patient?

An adult male patient is evaluated during morning rounds on the surgical ward. He is currently on postoperative day 3 following an emergent partial colectomy for a perforated diverticulum. At the time of presentation, he met criteria for sepsis and was empirically started on intravenous meropenem. His clinical course has steadily improved following source control. Today, his temperature is 37.1°C (98.8°F), blood pressure is 122/78 mmHg, and pulse is 76/min. He is tolerating a soft diet, and his bowel function has returned. His white blood cell count has decreased from 18,000/mm³ on admission to 8,500/mm³. Intraoperative peritoneal fluid cultures now demonstrate heavy growth of Escherichia coli and Bacteroides fragilis. Susceptibility testing for the E. coli isolate shows resistance to ampicillin but susceptibility to ciprofloxacin, ceftriaxone, and trimethoprim-sulfamethoxazole. Admission blood cultures have remained sterile. Which of the following is the most appropriate next step in pharmacotherapy?

A $48$-year-old woman arrives at the emergency department reporting sudden-onset pleuritic chest pain and breathlessness that began two hours ago. She has a history of type 2 diabetes mellitus and chronic kidney disease. She underwent a hysterectomy for uterine fibroids three weeks ago. Her temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $130/85$ mm Hg, pulse is $118$/min, and respirations are $26$/min. Pulse oximetry shows $91\%$ on room air. Examination demonstrates a swollen, tender left calf. Lungs are clear to auscultation bilaterally. Cardiac examination reveals a regular tachycardia but no murmurs or gallops.

Laboratory results are as follows:

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

During morning rounds, the attending physician reviews the progress of a 71-year-old man who was admitted 4 days ago with shortness of breath, pleuritic chest pain, and a left-sided pulmonary consolidation. The patient was diagnosed with severe community-acquired pneumonia and started on an empiric regimen of intravenous ceftriaxone and azithromycin. Blood cultures collected in the emergency department have yielded *Streptococcus pneumoniae*. Susceptibility testing demonstrates that the organism is highly sensitive to penicillin, amoxicillin, and moxifloxacin, but exhibits resistance to macrolides. The patient has shown marked clinical improvement; he is currently breathing comfortably on ambient air, successfully eating solid meals, and has recorded no temperature elevations for the past 24 hours. His current vital signs show a temperature of 37.0 °C (98.6 °F), blood pressure of 132/82 mm Hg, heart rate of 74/min, and respiratory rate of 14/min. Based on the culture results and clinical status, which of the following is the most appropriate pharmacological management?

A 28-year-old female nurse is evaluated in the clinic for a 6-week history of palpitations, insomnia, irritability, and a $4$-kg ($8.8$-lb) weight loss. She denies any preceding viral illnesses, neck pain, or changes in vision. Her temperature is $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), blood pressure is $134/74\ \text{mmHg}$, and pulse is $112/\text{min}$. Physical examination reveals an anxious-appearing woman with a fine resting tremor of the outstretched hands. Her skin is warm and diaphoretic. The thyroid gland is nonpalpable and nontender. There is no proptosis or extraocular muscle weakness. Laboratory studies show the following:

Thyroid-stimulating hormone (TSH): $< 0.01\ \mu\text{U/mL}$ (Normal: $0.5$ - $5.0\ \mu\text{U/mL}$)
Free thyroxine (T4): $0.4\ \text{ng/dL}$ (Normal: $0.9$ - $1.7\ \text{ng/dL}$)
Total triiodothyronine (T3): $310\ \text{ng/dL}$ (Normal: $80$ - $200\ \text{ng/dL}$)

Which of the following is the most likely cause of this patient's symptoms?

A patient presents with treatment-resistant hypertension and is found to have unprovoked hypokalemia on routine laboratory testing. The physician suspects primary hyperaldosteronism. Arrange the following steps of the diagnostic evaluation in the correct chronological order.

A 45-year-old man presents to the clinic for chronic diarrhea and recurrent severe abdominal pain for the past 6 months. He states that he has been taking high-dose over-the-counter omeprazole with minimal relief. Vital signs are within normal limits. Physical examination reveals mild epigastric tenderness to deep palpation. An upper gastrointestinal endoscopy is performed, revealing prominent gastric folds and multiple ulcerations in the gastric body, duodenal bulb, and distal duodenum. A gastric aspirate obtained during the endoscopy shows a pH of 1.4. The physician suspects a neuroendocrine tumor as the underlying cause of the patient's presentation.

Arrange the following subsequent steps in the most appropriate chronological sequence for the definitive diagnosis and management of this patient's suspected condition.

A $45$-year-old woman is evaluated in the intensive care unit for worsening oxygenation. She was admitted $3$ days ago for severe acute pancreatitis. Yesterday, she developed progressive dyspnea and hypoxemia requiring endotracheal intubation. Her predicted body weight is $60$ kg. She is currently sedated and paralyzed. Temperature is $37.4^\circ$ C ($99.3^\circ$ F), blood pressure is $110/70$ mm Hg, and pulse is $98$/min.

Mechanical ventilator settings (volume assist-control mode) are as follows:
Tidal volume: $550$ mL
Respiratory rate: $18$/min
Positive end-expiratory pressure (PEEP): $5$ cm H $_2$ O
Fraction of inspired oxygen (FiO $_2$): $0.80$

Arterial blood gas analysis reveals:
pH: $7.31$
PaCO $_2$: $48$ mm Hg
PaO $_2$: $56$ mm Hg

Chest radiograph shows diffuse bilateral alveolar opacities. Echocardiogram shows a normal left ventricular ejection fraction and no valvular abnormalities. Which of the following are the most appropriate next steps in the management of this patient's respiratory failure? (Select all that apply)

Match each characteristic histological finding and clinical presentation to the corresponding malabsorption disorder.

A $54$-year-old man is brought to the emergency department via ambulance after his wife found him lethargic at home. She reports that he has a medical history of hypertension, major depressive disorder, and hyperlipidemia. Empty bottles of metoprolol and hydrochlorothiazide were found near his bed. On arrival, the patient is minimally responsive. His temperature is $36.5^\circ\text{C}$ ($97.7^\circ\text{F}$), blood pressure is $70/40$ mmHg, pulse is $34$/min, and respiratory rate is $14$/min. The $12$-lead electrocardiogram demonstrates sinus bradycardia with a first-degree atrioventricular block and no acute ST-segment changes. Intravenous access is established, and a $1$-liter bolus of normal saline is rapidly infused with no improvement in hemodynamics.

Arrange the following subsequent interventions in the most appropriate chronological sequence for the emergency management of this patient's condition.

A 24-year-old pregnant woman at 14 weeks gestation presents for her initial prenatal visit. Routine prenatal screening reveals a positive rapid plasma reagin (RPR) test at a titer of 1:32. The patient reports a history of severe generalized urticaria and wheezing immediately after taking amoxicillin during childhood. She currently has no genital lesions or neurological symptoms. Arrange the following management steps in the most appropriate sequential order for this patient.

While rounding in the intensive care unit, a physician evaluates an 82-year-old female resident of an assisted living facility who was recently admitted for severe right-sided abdominal pain and high fever. The patient's daughter reports that her mother developed a yellowish discoloration of her eyes yesterday and became increasingly lethargic this morning. Vital signs include a temperature of $39.4^\circ\text{C}$ ($102.9^\circ\text{F}$), blood pressure of $82/50 \text{ mmHg}$, and a pulse of $122/\text{min}$. Physical examination is notable for scleral icterus and significant guarding in the right upper quadrant. Laboratory results include a leukocyte count of $19,500/\text{mm}^3$, a total bilirubin of $5.8 \text{ mg/dL}$ (direct $4.5 \text{ mg/dL}$), and an alkaline phosphatase of $410 \text{ U/L}$. Despite receiving a $2\text{ L}$ intravenous bolus of lactated Ringer's solution and empiric broad-spectrum antibiotics over the past hour, the patient's blood pressure remains $84/52 \text{ mmHg}$.

Which of the following interventions should be prioritized next for this patient?

A 42-year-old man comes to the physician due to a 3-month history of palpitations, heat intolerance, and increased sweating. He has lost 5 kg (11 lb) during this period despite a normal appetite. He also mentions experiencing mild, dull headaches and occasional difficulty seeing vehicles in his peripheral vision while driving. Vital signs show a heart rate of 110/min and a blood pressure of 140/85 mm Hg. Physical examination reveals a fine hand tremor, hyperreflexia, and a diffusely enlarged, non-tender thyroid gland without palpable nodules. Extraocular movements are intact, and there is no proptosis.

Laboratory studies show:
Thyroid-stimulating hormone (TSH): 7.2 µU/mL (Normal: 0.4–4.0 µU/mL)
Free thyroxine (T4): 2.8 ng/dL (Normal: 0.9–1.7 ng/dL)

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

Progressive dyspnea and persistent chills over the past week prompt the hospitalization of a $34$-year-old woman with a well-documented history of injection drug use. Initial blood cultures are drawn, and she is started on empiric intravenous vancomycin and cefepime. On the second day of admission, the nursing staff calls for urgent evaluation due to a sudden decline in her mental status. Vital signs show a temperature of $38.8^\circ C$ ($101.8^\circ F$), blood pressure of $72/40$ mmHg, heart rate of $134$/min, and respiratory rate of $28$/min. Her extremities are cool with thread-like peripheral pulses. Cardiac auscultation reveals tachycardia with a soft first heart sound ($S_1$), a prominent third heart sound ($S_3$), and a short, early diastolic decrescendo murmur best heard along the left sternal border. Lung auscultation demonstrates bilateral crackles extending to the mid-lung fields along with scattered expiratory wheezes. A bedside echocardiogram reveals a $1.6$-cm highly mobile echodensity attached to the aortic valve, accompanied by severe leaflet destruction and massive retrograde flow into a normal-sized left ventricle. Which of the following is the most appropriate next step in the management of this patient?

A 68-year-old man is evaluated in the clinic for progressive fatigue and a 6-kg (13.2-lb) weight loss over the past four months. He reports occasional dark stools but denies abdominal pain, nausea, or vomiting. His past medical history is unremarkable, and he has not had a colonoscopy in the past 15 years. Vital signs are within normal limits. Laboratory results show a hemoglobin of 9.4 g/dL, mean corpuscular volume of 74 fL, and ferritin of 10 ng/mL. Based on his presentation, a lower gastrointestinal malignancy is highly suspected. Arrange the following diagnostic and therapeutic steps in the most appropriate chronological order for the evaluation and management of this patient.

During morning rounds in the intensive care unit, the medical team evaluates a $66$-year-old man who has become increasingly lethargic over the past $12$ hours. He was admitted four days prior for management of severe right-sided heart failure secondary to chronic cor pulmonale. His home medications, which include a long-acting muscarinic antagonist and a long-acting beta-agonist, were continued on admission. Over the past $72$ hours, he has been receiving aggressive intravenous bumetanide therapy, producing approximately $4.5\text{ L}$ of urine per day. Today, his temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $102/64\text{ mm Hg}$, pulse is $92/\text{min}$, and respiratory rate is $10/\text{min}$. Physical examination shows flat neck veins when supine. Lung auscultation reveals distant breath sounds bilaterally but no crackles or wheezes. Arterial blood gas analysis on room air reveals:

pH: $7.52$
$\text{PaCO}_2$: $54\text{ mm Hg}$
$\text{PaO}_2$: $62\text{ mm Hg}$
$\text{HCO}_3^-$: $43\text{ mEq/L}$

Which of the following mechanisms is the primary cause of this patient's current acid-base disturbance?

Review the distinct patterns of serum calcium, phosphorus, and parathyroid hormone (PTH) abnormalities described below. Match each clinical and laboratory profile with its corresponding endocrine or metabolic disorder.

A 52-year-old woman is evaluated in the emergency department for an 8-hour history of severe, steady right upper quadrant abdominal pain that radiates to her back, accompanied by nausea. Her temperature is 37.2°C (99.0°F), blood pressure is 130/80 mm Hg, and pulse is 88/min. Physical examination shows scleral icterus and right upper quadrant tenderness without guarding or rebound. Laboratory studies show:

- Leukocyte count: $8,500/\text{mm}^3$
- Total bilirubin: $2.4 \text{ mg/dL}$
- Alkaline phosphatase: $260 \text{ U/L}$
- Aspartate aminotransferase (AST): $115 \text{ U/L}$
- Alanine aminotransferase (ALT): $120 \text{ U/L}$
- Lipase: $40 \text{ U/L}$

Arrange the following clinical interventions in the most appropriate chronological sequence for the complete evaluation and management of this patient, starting from her immediate arrival. Assume that any diagnostic imaging performed reveals findings consistent with an intermediate probability for choledocholithiasis (e.g., a dilated common bile duct without a definitively visualized ductal stone).