Internal Medicine

A $56$-year-old male patient is evaluated in the clinic for a $6$-month history of progressive fatigue, cold intolerance, and erectile dysfunction. He also notes that he has recently scraped the side of his car twice while pulling out of his garage, which he attributes to increasing clumsiness. His medical history is unremarkable, and he takes no medications. Blood pressure is $110/70$ mmHg and pulse is $56$/min. Physical examination demonstrates a delayed relaxation phase of the deep tendon reflexes and bilateral loss of peripheral vision in the temporal fields. Laboratory studies show the following:

Sodium: $135$ mEq/L
Thyroid-stimulating hormone (TSH): $2.2$ $\mu$ U/mL (Normal: $0.4-4.2$ $\mu$ U/mL)
Free thyroxine (T4): $0.5$ ng/dL (Normal: $0.9-2.4$ ng/dL)
Total testosterone: $140$ ng/dL (Normal: $300-1000$ ng/dL)

Which of the following best describes the pathogenesis of this patient's thyroid laboratory abnormalities?

A $65$-year-old man with a history of alcohol-associated cirrhosis, chronic obstructive pulmonary disease (COPD), and a recent admission for an upper gastrointestinal bleed one month ago presents to the emergency department with a $2$-day history of progressively worsening shortness of breath, increased abdominal girth, and mild lethargy.

Physical examination reveals an alert but mildly lethargic patient who is oriented to person and place only. Scleral icterus is present. Jugular venous pulsation is $6 \text{ cm H}_2\text{O}$. Lung examination shows decreased breath sounds and dullness to percussion over the right lower two-thirds of the lung field, with scattered end-expiratory wheezes bilaterally. The abdomen is distended, non-tender, and has shifting dullness. Bilateral $2+$ pitting lower extremity edema and asterixis are present.

Laboratory studies reveal the following:

Chest radiograph demonstrates a large right-sided pleural effusion without mediastinal shift or focal consolidations. A diagnostic paracentesis yields clear, yellow fluid with a total protein of $1.1 \text{ g/dL}$ and a neutrophil count of $80/\text{mm}^3$. The patient is currently receiving intravenous piperacillin-tazobactam, which was started empirically by a transferring facility $24$ hours ago for presumed pneumonia.

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

A 22-year-old woman is brought to the emergency department by her roommate due to confusion, nausea, and ringing in her ears for the past several hours. The roommate found an empty bottle of over-the-counter pain relievers in her room. On physical examination, her temperature is 37.8°C (100.0°F), blood pressure is 110/70 mm Hg, pulse is 115/min, and respiratory rate is 28/min. She appears agitated and diaphoretic. Laboratory results are as follows:

Which of the following best describes this patient's acid-base status?

A 48-year-old woman presents to the outpatient clinic with a 5-month history of worsening fatigue, unintentional weight gain, and cold intolerance. She also reports bilateral milky nipple discharge and absence of menses for the past 6 months. She has no significant past medical history and takes no medications. Vital signs show a temperature of $36.2^{\circ}\text{C}$ ($97.2^{\circ}\text{F}$), blood pressure of $105/65\text{ mmHg}$, and pulse of $54\text{/min}$. Physical examination reveals dry skin and a delayed relaxation phase of the deep tendon reflexes. Visual field testing is unremarkable. Laboratory results are as follows:

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

Match each clinical exposure scenario with the most appropriate pharmacological prophylaxis or empiric antimicrobial regimen.

Match each high-resolution esophageal manometry (HRM) profile to its corresponding pathophysiologic diagnosis according to the Chicago Classification.

An elderly resident of a skilled nursing facility is transferred to the intensive care unit following the sudden onset of high-volume, painless hematochezia. Initial assessment reveals profound hypotension (blood pressure $78/48 \text{ mm Hg}$) and marked tachycardia (heart rate $128/\text{min}$). Following aggressive intravenous volume expansion with isotonic crystalloids and transfusion of uncrossmatched type O-negative packed red blood cells, the patient's hemodynamic status normalizes. However, the passage of copious maroon-colored stool continues.

Arrange the following diagnostic and therapeutic interventions in the correct algorithmic sequence according to current clinical guidelines for the management of severe hematochezia.

Assume that each successive diagnostic step fails to isolate the source, subsequent non-invasive imaging successfully localizes the lesion but endovascular techniques fail to achieve definitive hemostasis, and open surgical rescue is ultimately mandated.

A 48-year-old man is evaluated for resistant hypertension and muscle cramps. He currently takes maximum tolerated doses of amlodipine, lisinopril, and chlorthalidone. His blood pressure is 168/104 mmHg. Laboratory evaluation reveals a serum potassium of 2.8 mEq/L and a serum sodium of 145 mEq/L. A secondary cause of hypertension is suspected. Assuming the patient's condition is ultimately driven by a unilateral aldosterone-producing adenoma, arrange the following steps in the correct chronological sequence required for the definitive diagnosis and management of this condition.

An inpatient ward physician is paged regarding a $54$-year-old individual with a history of alcohol-related cirrhosis who has developed a new-onset fever. The patient was admitted the previous day for therapeutic drainage of large-volume ascites. Assessment reveals a temperature of $38.4^\circ\text{C}$ ($101.1^\circ\text{F}$). The abdomen is visibly distended, demonstrating shifting dullness and diffuse tenderness upon palpation, though no rebound guarding is present. A timely diagnostic paracentesis yields ascitic fluid with an absolute neutrophil count of $520/\text{mm}^3$. Ascitic fluid and blood cultures are pending. Which of the following is the most appropriate next step in management?

Match each patient's clinical presentation with the most likely corresponding finding on a peripheral blood smear.

An evaluation is requested for a $45$-year-old woman suffering from resistant hypertension. Her current daily medication regimen includes maximal tolerated doses of amlodipine, valsartan, and hydrochlorothiazide. In the clinic, her blood pressure is persistently elevated at $172/104\text{ mm Hg}$, with a heart rate of $78\text{ /min}$. A basic metabolic panel reveals a serum potassium concentration of $2.8\text{ mEq/L}$. The physician suspects primary hyperaldosteronism as the underlying etiology. Arrange the following clinical steps in the most appropriate chronological sequence for the definitive workup and management of this patient.

A 72-year-old man with a long-standing history of tobacco use disorder, emphysema, and ischemic cardiomyopathy presents to the emergency department complaining of acutely worsening shortness of breath for the past 24 hours. He appears visibly distressed and is leaning forward in the tripod position. Vital signs show a temperature of 37.2°C (99.0°F), blood pressure of 145/88 mm Hg, pulse of 105/min, and respiratory rate of 28/min. Pulse oximetry reveals an oxygen saturation of 88% on room air. Physical examination demonstrates diffuse expiratory wheezing bilaterally, but auscultation of the heart sounds is difficult due to the noisy lung fields. The patient has mild bilateral pitting edema at the ankles, which he states is chronic. Given the overlapping clinical features of his comorbidities, which of the following laboratory tests is most useful to rapidly determine whether his acute presentation is primarily driven by decompensated heart failure rather than a pulmonary exacerbation?

A 68-year-old man is brought to the emergency department due to acute-onset, severe shortness of breath. He reports a dry cough and diffuse wheezing that began 2 hours prior to arrival. His medical background includes severe chronic obstructive pulmonary disease (COPD), essential hypertension, and a previous anterior myocardial infarction. At home, he used his albuterol inhaler three times with no improvement. Vital signs include a temperature of $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure of $178/104\text{ mm Hg}$, heart rate of $114/\text{min}$, and respiratory rate of $28/\text{min}$. Pulse oximetry reveals an oxygen saturation of $86\%$ on room air. Physical examination shows a diaphoretic man in a tripod position, utilizing accessory muscles of respiration. The jugular venous pressure is visually elevated to $11\text{ cm H}_2\text{O}$. Cardiac auscultation reveals a regular tachycardia with a prominent early diastolic extra heart sound. Lung auscultation demonstrates bilateral expiratory wheezing; notably, no crackles are auscultated. A chest radiograph reveals hyperinflated lung fields, an enlarged cardiac silhouette, and cephalization of the pulmonary vasculature, without any focal consolidation. The patient is immediately initiated on noninvasive positive pressure ventilation (NIPPV). Over the next 15 minutes, his work of breathing and oxygen saturation improve significantly. Which of the following mechanisms best explains the primary physiological basis for this patient's rapid clinical improvement?

A 76-year-old woman is admitted to the intensive care unit with severe, poorly localized abdominal pain out of proportion to physical examination findings, accompanied by bloody diarrhea. Her medical history is significant for atrial fibrillation. She is hypotensive and tachycardic. Laboratory testing reveals a serum lactate of $8.5$ mmol/L. Arterial blood gas and basic metabolic panel results are as follows:

The physician determines that the patient has a primary high anion gap metabolic acidosis secondary to suspected acute mesenteric ischemia. According to Winter's formula, what is the exact calculated midpoint of the target expected arterial $pCO_2$ (in mmHg) representing appropriate respiratory compensation?

A 62-year-old postmenopausal woman is found to have an incidental elevated serum total calcium of 11.4 mg/dL during a routine health maintenance examination. She has no history of nephrolithiasis, bone pain, or abdominal discomfort. Assuming her clinical evaluation ultimately leads to a diagnosis of primary hyperparathyroidism requiring surgical intervention, arrange the following clinical steps in the most appropriate chronological sequence for her workup and management.

A 38-year-old man seeks evaluation at an outpatient clinic for a four-month history of unremitting, voluminous watery diarrhea accompanied by a $12 \text{ kg}$ weight loss, intermittent low-grade fevers, and diffuse abdominal cramping. He has a history of advanced human immunodeficiency virus (HIV) infection but discontinued his antiretroviral therapy two years ago due to medication fatigue. His last known CD4+ T-lymphocyte count was $35/\text{mm}^3$. Vital signs show a temperature of $37.9^\circ\text{C}$, blood pressure of $105/65 \text{ mm Hg}$, and heart rate of $98/\text{min}$. Physical examination is notable for temporal wasting and mild, diffuse abdominal tenderness without rebound or guarding. Laboratory studies reveal a mild normocytic anemia and an elevated serum alkaline phosphatase level. Stool studies are negative for ova, parasites, and *Clostridioides difficile* toxin. An esophagogastroduodenoscopy (EGD) is performed. Biopsy of the descending duodenum reveals blunted villi and a dense infiltration of the lamina propria with enlarged, foamy macrophages. These macrophages stain strongly positive with periodic acid-Schiff (PAS). An acid-fast bacillus (AFB) stain of the tissue is subsequently performed and is positive. Based on these findings, which of the following is the most appropriate targeted pharmacotherapy for this patient's gastrointestinal condition?

A 58-year-old man is evaluated in the hospital on the third day of his admission for acute pyelonephritis. He originally presented with right flank pain, chills, and dysuria. At the time of admission, his temperature was $39.2^\circ \text{C}$ ($102.6^\circ \text{F}$), heart rate was $110/\text{min}$, and blood pressure was $105/65 \text{ mmHg}$. He was empirically started on intravenous piperacillin-tazobactam.

Today, the patient reports significant improvement in his symptoms. His flank pain has resolved, and he has been afebrile for the past 24 hours. Current vital signs are temperature $37.1^\circ \text{C}$ ($98.8^\circ \text{F}$), heart rate $82/\text{min}$, and blood pressure $122/78 \text{ mmHg}$. He is tolerating a regular diet.

Blood cultures drawn on admission show no growth. Urine cultures from admission grow $>100,000 \text{ CFU/mL}$ of *Escherichia coli*. Antimicrobial susceptibility testing results are as follows:

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

Match each clinical and diagnostic presentation to the most likely hepatic or biliary disorder.

An emergency response team brings a 54-year-old male to the resuscitation bay after he experienced sudden, crushing central chest pain while working in his garden. The pain radiates to his jaw and is accompanied by profuse sweating. En route to the hospital, the transport personnel administered 325 mg of chewable aspirin and one dose of sublingual nitroglycerin. Shortly after receiving the nitroglycerin, the patient developed profound lightheadedness.

Currently, his blood pressure is 78/48 mmHg, and his pulse is 52/min. His respiratory rate is 16/min, and oxygen saturation is 96% on room air.

Physical examination reveals clear lung fields bilaterally. The jugular veins are markedly distended while the patient is positioned at a 45-degree angle.

A 12-lead electrocardiogram demonstrates 3-mm ST-segment elevations in leads II, III, and aVF, as well as ST-segment depressions in leads I and aVL.

Which of the following is the most appropriate initial step to manage this patient's hemodynamic instability?

Match the following Hepatitis B serologic profiles obtained during routine screening or acute evaluation to their most accurate clinical interpretation.