Internal Medicine

A 68-year-old woman is evaluated in the hospital for new-onset diarrhea. She was admitted seven days ago for the management of community-acquired pneumonia and has been receiving intravenous ceftriaxone and azithromycin. Over the past two days, she has developed frequent, profuse, watery bowel movements accompanied by diffuse abdominal cramping. Her temperature is $38.2^{\circ}\mathrm{C}$ ($100.8^{\circ}\mathrm{F}$), blood pressure is $112/74\;\mathrm{mmHg}$, and pulse is $98/\mathrm{min}$. Physical examination reveals mild lower abdominal tenderness without guarding or rebound. Laboratory studies show a leukocyte count of $15,500/\mathrm{mm}^3$. A stool enzyme immunoassay is positive for *Clostridioides difficile* glutamate dehydrogenase antigen and toxin A/B. Which of the following is the most appropriate targeted pharmacotherapy for this patient's gastrointestinal infection?

Match the following valvular pathologies with their classic auscultatory findings on physical examination.

A 28-year-old woman presents to the clinic with an 8-month history of progressive exertional dyspnea, fatigue, and one episode of syncope while climbing stairs. She has no significant past medical history and takes no medications. Her blood pressure is 110/70 mm Hg, pulse is 88/min, and respirations are 16/min. Pulse oximetry shows 97% on room air. Physical examination reveals clear lungs, a prominent right ventricular heave, and a loud pulmonic component of the second heart sound. There is trace lower extremity edema. A transthoracic echocardiogram demonstrates right ventricular dilation, septal flattening during systole, and an estimated right ventricular systolic pressure of 55 mm Hg. The left ventricular size and systolic function are normal, with no significant valvular abnormalities. Pulmonary function testing and high-resolution computed tomography (HRCT) of the chest are unremarkable.

Arrange the following steps in the most appropriate sequential order for the continued diagnostic evaluation and management of this patient's condition.

A $70$-year-old woman presents to the emergency department with severe shortness of breath and wheezing that began $2$ hours ago. She has a history of poorly controlled hypertension and a $30$-pack-year smoking history. Her temperature is $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure is $170/95\text{ mmHg}$, pulse is $112/\text{min}$, and oxygen saturation is $88\%$ on room air. Physical examination reveals distended jugular veins, a third heart sound (S3) on cardiac auscultation, and bilateral diffuse wheezing intermixed with bibasilar crackles. Which of the following is the most appropriate initial pharmacologic therapy for this patient?

Match the following clinical presentations and auscultatory findings with their most likely underlying structural or valvular pathology.

Match the following characteristic arterial pulse abnormalities identified on physical examination with their most likely underlying cardiovascular pathology.

Match each patient's clinical presentation with the most accurate description of the underlying pathophysiologic mechanism responsible for their condition.

A 58-year-old man was intubated and mechanically ventilated 5 days ago for severe community-acquired pneumonia. Today, his clinical condition has significantly improved. He is afebrile, his oxygen saturation is 96% on a fraction of inspired oxygen (FiO2) of 0.35, and he requires no vasopressor support. The critical care team decides to initiate the process of liberating the patient from mechanical ventilation.

Arrange the following steps in the correct chronological sequence for standard mechanical ventilation liberation.

A $52$-year-old man comes to the clinic reporting a $5$-month history of worsening fatigue, generalized weakness, and decreased libido. He has also been experiencing intermittent, dull headaches and occasional blurry vision, especially when driving. He does not take any medications. Vital signs are within normal limits. Physical examination reveals delayed relaxation phase of the deep tendon reflexes. Visual field testing by confrontation demonstrates decreased peripheral vision bilaterally.

Laboratory results are as follows:

Thyroid-stimulating hormone (TSH): $1.8$ $\mu$ U/mL (Normal: $0.4-4.2$ $\mu$ U/mL)
Free thyroxine (T4): $0.5$ ng/dL (Normal: $0.9-1.7$ ng/dL)
Testosterone, total: $140$ ng/dL (Normal: $300-1000$ ng/dL)
Luteinizing hormone (LH): $1.2$ mIU/mL (Normal: $1.5-9.3$ mIU/mL)

Which of the following is the most likely underlying mechanism for this patient's thyroid laboratory findings?

A 54-year-old male is currently hospitalized for a right lower lobe community-acquired pneumonia. On hospital day 4, he develops worsening pleuritic chest pain and a persistent fever of $38.9^\circ\text{C}$ ($102.0^\circ\text{F}$). A repeat chest radiograph demonstrates a new, moderate-sized right pleural effusion. Over the subsequent two weeks, his pleural disease becomes increasingly complex, requiring a step-wise escalation of therapy. Arrange the following interventions in the correct chronological order of standard management for an evolving parapneumonic effusion, from initial evaluation to the definitive treatment of refractory multi-loculated empyema.

A $62$-year-old woman who has been mechanically ventilated for $6$ days due to severe acute respiratory distress syndrome (ARDS) following a viral infection develops a new fever of $39.1^\circ\text{C}$ ($102.4^\circ\text{F}$), leukocytosis, and increased purulent endotracheal secretions. A portable chest radiograph reveals a new right lower lobe alveolar infiltrate. The patient is hemodynamically stable. Arrange the following steps in the correct chronological order for the standard diagnostic and therapeutic management of suspected ventilator-associated pneumonia (VAP) in this patient.

A $29$-year-old primigravida at $30$ weeks gestation is brought to the emergency department due to rapidly progressive shortness of breath, palpitations, and hemoptysis that began $24$ hours ago. She reports a sense of overwhelming anxiety and impending doom. She has a history of bipolar I disorder, currently well-controlled on lamotrigine, and mild intermittent asthma since childhood. Her temperature is $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure is $112/68$ mmHg, pulse is $135$ /min and irregularly irregular, and respiratory rate is $28$ /min. Oxygen saturation is $88\%$ on room air and improves to $94\%$ on supplemental oxygen.

Physical examination reveals prominent jugular venous pulsations with absent 'a' waves. Pulmonary auscultation reveals bilateral crackles up to the mid-scapulae with scattered expiratory wheezes. Cardiac auscultation reveals a loud first heart sound, a high-frequency sound in early diastole, and a low-pitched mid-diastolic sound best heard at the apex in the left lateral decubitus position.

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

Match each patient's clinical presentation of chronic diarrhea and malabsorption with the most likely corresponding diagnostic finding or histologic feature.

A 72-year-old retired teacher presents to the urgent care clinic with progressively worsening breathing difficulty over the past three days. He reports a sensation of chest tightness and a new cough that produces clear, frothy sputum. His medical history includes hypertension, coronary artery disease, and a 35-pack-year smoking history, though he quit five years ago. Over the last two nights, he has frequently awakened gasping for air and has resorted to sleeping upright in a recliner chair. His current home medications are aspirin, metoprolol, and lisinopril. Vital signs are temperature 36.8°C (98.2°F), blood pressure 168/94 mm Hg, pulse 110/min, and respiratory rate 24/min. Pulse oximetry is 88% on room air. Physical examination reveals prominent jugular venous distention. Lung auscultation demonstrates widespread expiratory wheezing and fine crackles extending to the mid-lung fields bilaterally. Cardiac examination reveals tachycardia with a regular rhythm and an extra low-frequency heart sound occurring just after S2. There is 2+ bilateral pitting edema extending to the mid-calf. Which of the following is the most appropriate initial pharmacologic management for this patient?

A 35-year-old man comes to the clinic due to a 3-week history of right upper quadrant abdominal pain, low-grade fevers, and a 4-kg (8.8-lb) weight loss. He returned from a 6-week backpacking trip across Southeast Asia one month ago. During his trip, he had a self-limited episode of bloody diarrhea that resolved after a few days without medical intervention. His temperature is 38.3°C (100.9°F), blood pressure is 120/80 mmHg, and pulse is 95/min. Physical examination reveals tenderness to palpation in the right upper quadrant and moderate hepatomegaly. Laboratory studies show a leukocyte count of 14,500/mm³ and an alkaline phosphatase level of 340 U/L. An abdominal ultrasound demonstrates a solitary, 6-cm, well-demarcated, hypoechoic mass in the right lobe of the liver. Enzyme-linked immunosorbent assay (ELISA) is positive for Entamoeba histolytica antibodies. Which of the following is the most appropriate next step in management?

Calcium and phosphorus homeostasis is tightly regulated by parathyroid hormone (PTH), vitamin D, and renal function. Disruptions in this balance yield distinct laboratory patterns. Match each of the following serum laboratory profiles to its most likely underlying pathophysiologic diagnosis.

A 27-year-old man visits the emergency department complaining of sudden, intense shortness of breath and chest tightness that began one hour ago. He has a known history of mild persistent asthma but has not used his maintenance inhaler for the past month. His temperature is $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), blood pressure is $138/82\text{ mmHg}$, pulse is $115/\text{min}$, and respiratory rate is $26/\text{min}$. Pulse oximetry shows an oxygen saturation of $93\%$ on room air. Physical examination reveals an anxious patient sitting upright. Diffuse expiratory wheezes are heard bilaterally with a prolonged expiratory phase. There is no lower extremity edema or jugular venous distention. A point-of-care arterial blood gas analysis on room air shows a pH of $7.50$, $\text{PaCO}_2$ of $27\text{ mmHg}$, and $\text{PaO}_2$ of $68\text{ mmHg}$. A portable chest radiograph displays hyperinflation of both lungs but no focal opacities. Which of the following is the most appropriate next step in the management of this patient?

A 65-year-old man presents to the emergency department with sudden-onset, severe, tearing chest pain that radiates to his back. His blood pressure is 190/110 mmHg in the right arm and 140/80 mmHg in the left arm. His heart rate is 112/min. A bedside chest radiograph shows a widened mediastinum. Suspecting an acute aortic dissection, arrange the following management steps in the most appropriate chronological order.

A 39-year-old woman is evaluated for progressive weight gain, proximal muscle weakness, and new-onset facial hair growth over the past year. Physical examination reveals central adiposity, facial plethora, a dorsocervical fat pad, and wide violaceous abdominal striae. Her blood pressure is 158/96 mm Hg. Initial screening with two separate 24-hour urine free cortisol measurements and an overnight low-dose dexamethasone suppression test confirm the diagnosis of endogenous hypercortisolism.

Arrange the following diagnostic steps in the most appropriate chronological sequence to determine the specific etiology of her condition. Assume each test is performed sequentially and its result dictates the necessity of the immediate next step in this patient's diagnostic pathway.

A 58-year-old man with a history of type 2 diabetes mellitus is evaluated in the inpatient ward. He was admitted two days ago with a three-day history of high fever, chills, and severe right upper quadrant abdominal pain. At admission, his temperature was 39.4°C (102.9°F). A contrast-enhanced abdominal CT scan revealed a 6.5-cm fluid-filled collection with peripheral enhancement in the right hepatic lobe.

The patient underwent prompt ultrasound-guided percutaneous drain placement. Empiric antimicrobial therapy with intravenous piperacillin-tazobactam was initiated.

Currently, on hospital day 3, the patient reports significant symptomatic improvement. His temperature is 37.2°C (99.0°F), and his vital signs are stable. The percutaneous drain is producing minimal serosanguinous output.

Microbiology results for both blood and abscess fluid cultures have returned, as shown below:

Based on these results, which of the following is the most appropriate next step in the pharmacologic management of this patient?