Internal Medicine

Match each clinical and laboratory presentation with the most likely underlying nephrological etiology.

A $71$-year-old woman is evaluated in the hospital for new-onset diarrhea. She was admitted $8$ days ago for a severe chronic obstructive pulmonary disease exacerbation, for which she was treated with intravenous methylprednisolone, nebulized bronchodilators, and a $5$-day course of oral levofloxacin. Over the past $48$ hours, she has developed crampy abdominal pain and $6$ to $8$ watery bowel movements daily. Her temperature is $38.1^\circ\text{C}$ ($100.6^\circ\text{F}$), blood pressure is $112/74\text{ mmHg}$, and pulse is $98/\text{min}$. Physical examination shows mild, diffuse abdominal tenderness without guarding or rebound. Laboratory studies reveal a leukocyte count of $18,500/\text{mm}^3$ and a serum creatinine of $1.4\text{ mg/dL}$ (baseline $0.9\text{ mg/dL}$). Stool enzyme immunoassay is positive for *Clostridioides difficile* glutamate dehydrogenase antigen and toxins A and B. Which of the following is the most appropriate targeted pharmacotherapy for this patient?

A 21-year-old female university student is evaluated in the urgent care clinic after her roommates noticed her acting increasingly confused and breathing rapidly over the past $4\text{ hours}$. She has a history of major depressive disorder and recently failed an important exam. She complains of a constant "buzzing" sound in her ears. Her temperature is $37.9^\circ\text{C}$ ($100.2^\circ\text{F}$), pulse is $118\text{/min}$, respirations are $30\text{/min}$, and blood pressure is $112/68\text{ mm Hg}$. Physical examination reveals an agitated, tachypneic patient with clear lung fields and no focal neurologic deficits.

Laboratory studies reveal the following:

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

Match each clinical presentation of a nephrologic or urologic emergency with its most appropriate targeted intervention.

A 45-year-old woman is admitted for severe symptomatic anemia secondary to abnormal uterine bleeding. Her hemoglobin is 6.2 g/dL. A transfusion of packed red blood cells is initiated. Fifteen minutes into the infusion, she complains of sudden-onset chills, severe lower back pain, and nausea. Her temperature is 38.9°C (102°F), blood pressure is 88/50 mmHg, pulse is 118/min, and respirations are 22/min. The Foley catheter bag shows a sudden change in urine color to dark reddish-brown. Arrange the following steps in the most appropriate chronological order for managing this patient's acute complication.

A 54-year-old man undergoes an upper gastrointestinal endoscopy for the evaluation of persistent dyspepsia and early satiety. The procedure reveals abnormal, thickened gastric folds in the antrum. Biopsies of the affected area show a dense infiltrate of atypical small lymphocytes in the lamina propria with characteristic lymphoepithelial lesions. Immunohistochemical staining confirms gastric extranodal marginal zone B-cell (MALT) lymphoma. Histologic examination of the non-neoplastic mucosa demonstrates the presence of curved, flagellated, gram-negative bacilli.

Arrange the following steps in the most appropriate chronological order for the definitive evaluation and management of this patient's condition.

A 74-year-old man is evaluated in the outpatient clinic due to a 24-hour history of exquisite right knee pain, swelling, and difficulty bearing weight. His medical history is significant for ischemic cardiomyopathy with a left ventricular ejection fraction of 30%, chronic kidney disease with a baseline serum creatinine of 2.1 mg/dL, and bilateral knee osteoarthritis. Current medications include carvedilol, lisinopril, furosemide, and low-dose aspirin. Vital signs are temperature 37.5°C (99.5°F), blood pressure 110/70 mmHg, heart rate 82/min, and respiratory rate 14/min. Physical examination reveals a markedly swollen, erythematous, and warm right knee with a palpable effusion. Arthrocentesis is performed, yielding turbid synovial fluid. Synovial fluid analysis shows a leukocyte count of 22,000/mm³ (75% neutrophils). Gram stain of the fluid shows no organisms. Polarized light microscopy demonstrates rhomboid-shaped crystals with weak positive birefringence. Which of the following is the most appropriate next step in management?

Match each patient's clinical presentation with the most appropriate targeted antimicrobial therapy.

A 74-year-old woman is brought to the emergency department due to the sudden onset of severe, unremitting pain in her right leg that began 3 hours ago. She states the pain started abruptly while she was sitting in a chair. Her medical history includes hypertension, hyperlipidemia, and atrial fibrillation. Her medications include lisinopril and metoprolol; however, she admits that she has not taken her apixaban for the past two weeks due to financial constraints. Her vital signs include a blood pressure of 142/88 mmHg, a pulse of 115/min and irregularly irregular, and a respiratory rate of 18/min. On physical examination, the right lower extremity is pale and cold to the touch from the mid-calf distally. The right dorsalis pedis and posterior tibial pulses are absent to palpation and cannot be detected by hand-held Doppler. Sensation is decreased over the dorsum of the right foot, and she has mild weakness during dorsiflexion of the toes. Which of the following is the most appropriate initial step in the management of this patient?

A 72-year-old woman presents to an urgent care clinic with a 3-day history of progressively worsening shortness of breath. She reports waking up in the middle of the night feeling as though she is suffocating and has started using three pillows to sleep comfortably. Her medical history is significant for long-standing, poorly controlled hypertension and osteoarthritis. Her temperature is 37.0°C (98.6°F), blood pressure is 170/100 mm Hg, pulse is 110/min, and respiratory rate is 24/min. Pulse oximetry shows 92% on room air. Physical examination reveals distended neck veins 5 cm above the sternal angle. Cardiac auscultation demonstrates a third heart sound (S3). Lung auscultation reveals bilateral basilar crackles and diffuse expiratory wheezing. Bilateral 2+ pitting edema is present in the lower extremities. Which of the following is the most appropriate next step in management?

A 68-year-old woman is brought to the emergency department by emergency medical services for severe, worsening shortness of breath over the last 24 hours. She has a history of ischemic cardiomyopathy with an ejection fraction of $30\%$, chronic obstructive pulmonary disease (COPD), and chronic kidney disease. Upon arrival, she is lethargic and confused. Her son is at the bedside and demands that she receive "only breathing treatments and no life support," despite the patient having a recently updated, legally valid advance directive explicitly requesting full interventions, including intubation and cardiopulmonary resuscitation, for acute reversible conditions.

Her temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $76/48$ mmHg, heart rate is $128$/min and irregular, and respiratory rate is $32$/min. Oxygen saturation is $82\%$ on room air.

Physical examination reveals jugular venous distention up to the angle of the mandible. Lung auscultation demonstrates diffuse bilateral expiratory wheezing with a significantly prolonged expiratory phase; no crackles are present. Heart sounds are rapid and irregular. The extremities are cold, clammy, and display mottled skin up to the knees.

An electrocardiogram shows atrial fibrillation with a rapid ventricular response.

Arterial blood gas analysis on room air reveals:
pH: $7.15$
$PaO_2$: $52$ mmHg
$PaCO_2$: $68$ mmHg
$HCO_3^-$: $23$ mEq/L
Lactate: $5.4$ mmol/L

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

A 62-year-old man is brought to the emergency department due to sudden-onset, severe chest pain that he describes as "tearing" and radiating to his upper back. He has a 20-year history of poorly controlled hypertension. His temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $215/115\text{ mm Hg}$ in the right arm and $178/92\text{ mm Hg}$ in the left arm, pulse is $112/\text{min}$, and respirations are $22/\text{min}$. Oxygen saturation is $97\%$ on room air. Physical examination reveals a bounding pulse and an early diastolic decrescendo murmur at the right upper sternal border. Electrocardiogram demonstrates sinus tachycardia and voltage criteria for left ventricular hypertrophy, but no acute ST-segment changes. A portable chest radiograph reveals a widened mediastinum. Arrange the following management steps in the most appropriate chronological order.

A $55$-year-old woman is brought to the emergency department by her husband due to severe, diffuse abdominal pain and repetitive vomiting that began $24$ hours ago. She reports that she has not passed gas or had a bowel movement for the past $2$ days. Her medical history is significant for a total abdominal hysterectomy $6$ years ago. Upon arrival, she appears lethargic and is in acute distress. Her temperature is $39.2^{\circ}\text{C}$ ($102.6^{\circ}\text{F}$), pulse is $130/\text{min}$, respirations are $24/\text{min}$, and blood pressure is $84/50\text{ mmHg}$. Physical examination reveals a markedly distended abdomen. Palpation demonstrates diffuse rigidity, involuntary guarding, and severe rebound tenderness. Bowel sounds are absent. Laboratory studies show a leukocyte count of $18,500/\text{mm}^3$ with $85\%$ neutrophils. An upright abdominal radiograph shows multiple dilated loops of small bowel with air-fluid levels and a paucity of gas in the colon. Which of the following is the most appropriate next step in the management of this patient?

Match each esophageal disorder to its classic clinical or diagnostic hallmark.

A 76-year-old man is evaluated in the emergency department for a sudden onset of severe lightheadedness and confusion that began one hour ago. His wife reports that he briefly lost consciousness before arrival. He has a history of hypertension and osteoarthritis. Current medications include lisinopril and acetaminophen. His temperature is 36.8°C (98.2°F), blood pressure is 82/50 mm Hg, and pulse is 32/min. Physical examination reveals delayed capillary refill and cool extremities. A 12-lead electrocardiogram demonstrates marked sinus bradycardia with no ischemic changes. He remains hypotensive despite an initial rapid infusion of intravenous fluids. Arrange the following management steps in the correct chronological sequence, from the most appropriate immediate intervention to the definitive long-term treatment assuming the underlying etiology is irreversible.

A $54$-year-old woman with a history of metastatic lung cancer is brought to the emergency department with severe shortness of breath, lightheadedness, and confusion. Her blood pressure is $80/52$ mmHg, heart rate is $124$/min, and respiratory rate is $26$/min. Pulse oximetry is $94\%$ on ambient air. Physical examination demonstrates visibly distended jugular veins, clear lung fields bilaterally, and distant, muffled heart sounds. Her systolic blood pressure drops by $18$ mmHg during inspiration. Arrange the following management steps in the most appropriate chronological sequence for this patient's acute cardiovascular emergency.

A $72$-year-old man visits the urgent care clinic complaining of progressive difficulty breathing and a non-productive cough over the past $3$ days. He states his "asthma" is acting up again and requests a refill of his inhalers. His past medical history includes severe chronic obstructive pulmonary disease (COPD) requiring $2$ L/min of home oxygen, ischemic heart disease with a prior myocardial infarction, and type $2$ diabetes mellitus. His current medications include inhaled tiotropium, inhaled fluticasone-salmeterol, and metformin. Vital signs reveal a temperature of $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure of $162/94$ mm Hg, heart rate of $115$/min, and respiratory rate of $26$/min. Oxygen saturation is $89\%$ on his baseline $2$ L/min oxygen. The patient is sitting upright and using accessory muscles to breathe. Examination of the neck demonstrates distended external jugular veins up to the angle of the mandible while sitting at a $45^\circ$ incline. Lung auscultation reveals diffuse expiratory wheezing and scattered fine crackles at the bilateral lung bases. Cardiac examination reveals a regular tachycardia with a low-frequency diastolic sound heard just after S2 at the cardiac apex. Abdominal exam reveals mild hepatomegaly. Bilateral pitting edema is noted up to the mid-calves. Bedside ultrasound of the lungs demonstrates diffuse, vertically oriented, laser-like artifacts extending from the pleural line to the bottom of the screen (B-lines) in all lung fields. Which of the following is the most appropriate initial pharmacological intervention for this patient's current condition?

Match each distinct electrocardiographic (ECG) finding with its most characteristic underlying structural or anatomical pathology.

A 72-year-old man visits the outpatient clinic reporting a four-week history of progressively worsening shortness of breath and a persistent, dry cough. His medical history includes coronary artery disease, ischemic cardiomyopathy with a left ventricular ejection fraction of 35%, paroxysmal atrial fibrillation, and mild chronic obstructive pulmonary disease. He smoked cigarettes for 30 years but quit a decade ago. Current medications include lisinopril, metoprolol succinate, spironolactone, apixaban, and an antiarrhythmic agent initiated six months ago to maintain normal sinus rhythm. Vital signs show a blood pressure of 128/78 mm Hg, a pulse of 68/min, and a respiratory rate of 20/min. Pulse oximetry is 91% on room air. Jugular venous pressure is normal at 6 cm $H_2O$. Lung auscultation reveals bilateral fine, "Velcro-like" inspiratory crackles, but no wheezing or rhonchi. Cardiac examination shows a regular rate and rhythm with no murmurs or gallops. There is no lower extremity edema. A high-resolution computed tomography scan of the chest demonstrates bilateral ground-glass opacities and reticular interstitial thickening. Which of the following is the most appropriate next step in the management of this patient?

Emergency medical services bring a 72-year-old woman to the acute care unit due to rapid clinical deterioration over the past $24$ hours. She initially complained of severe right-sided abdominal discomfort before becoming acutely confused. Her temperature is $39.2^\circ\text{C}$ ($102.6^\circ\text{F}$), blood pressure is $80/50\text{ mm Hg}$, pulse is $120/\text{min}$, and respiratory rate is $22/\text{min}$. Physical examination reveals distinct yellowing of the sclerae and profound tenderness upon palpation of the right upper quadrant, with no peritoneal signs. She is lethargic and disoriented to time and place. Laboratory studies show:

Right upper quadrant ultrasound demonstrates a dilated common bile duct measuring $12\text{ mm}$ (normal $< 8\text{ mm}$) with an echogenic focus casting a distal acoustic shadow. The gallbladder contains multiple gallstones but no pericholecystic fluid. Intravenous fluids and broad-spectrum antibiotics are initiated.

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