Internal Medicine

A 24-year-old man is brought to the emergency department by his roommate due to confusion, rapid breathing, and ringing in his ears after intentionally ingesting an unknown quantity of pills. On physical examination, temperature is 37.8°C (100.0°F), blood pressure is 110/70 mm Hg, pulse is 112/min, and respiratory rate is 28/min. The lungs are clear to auscultation. Laboratory studies show the following:

Serum sodium: 142 mEq/L
Serum potassium: 4.1 mEq/L
Serum chloride: 104 mEq/L
Serum bicarbonate: 14 mEq/L

Arterial blood gas analysis on room air reveals:
pH: 7.43
pCO2: 21 mm Hg
pO2: 98 mm Hg

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

A 65-year-old woman with a history of severe chronic obstructive pulmonary disease (COPD) is brought to the emergency department due to worsening shortness of breath, productive cough, and confusion over the past 3 days. She has also had decreased oral intake. Her temperature is 38.6°C (101.5°F), blood pressure is 90/55 mm Hg, pulse is 120/min, and respiratory rate is 28/min. Physical examination reveals bilateral diffuse wheezing and coarse crackles at the right lung base.

Laboratory studies show:
Serum sodium: 140 mEq/L
Serum potassium: 4.2 mEq/L
Serum chloride: 102 mEq/L
Serum bicarbonate: 14 mEq/L
Blood urea nitrogen: 35 mg/dL
Serum creatinine: 1.8 mg/dL (baseline 0.9 mg/dL)
Serum lactate: 4.5 mmol/L (normal: 0.5-2.2 mmol/L)

Arterial blood gas analysis on room air reveals:
pH: 7.21
$pCO_2$: 36 mm Hg
$pO_2$: 58 mm Hg

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

A physician evaluates a 68-year-old woman who is currently on hospital day 3 for the treatment of urosepsis. Upon admission to the intensive care unit three days ago, the patient was hypotensive and febrile. She received aggressive fluid resuscitation and was empirically started on intravenous vancomycin and cefepime. She was transferred to the general medical ward yesterday. Today, her vital signs are stable, she has been afebrile for 24 hours, and she is comfortably eating a regular diet. Initial blood and urine cultures now show growth of *Escherichia coli*. Antimicrobial susceptibility testing reveals the isolate is sensitive to ceftriaxone, ciprofloxacin, and trimethoprim-sulfamethoxazole, but resistant to ampicillin. Which of the following is the most appropriate next step in antibiotic therapy?

A 32-year-old woman comes to the office due to profound fatigue, weight gain, and cold intolerance over the past 4 months. She also reports that she has not had a menstrual period since the birth of her first child 8 months ago. Her pregnancy was complicated by prolonged labor and severe postpartum hemorrhage that required emergency blood transfusions. She was unable to breastfeed her infant. Blood pressure is 92/58 mm Hg and pulse is 56/min. Physical examination shows delayed relaxation of deep tendon reflexes. Laboratory studies show:

Thyroid-stimulating hormone (TSH): 1.2 mU/L (Normal: 0.5–5.0 mU/L)
Free thyroxine (T4): 0.4 ng/dL (Normal: 0.9–1.7 ng/dL)

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

A 58-year-old man is evaluated in the hospital prior to discharge. He was admitted four days ago for right upper quadrant abdominal pain, fever, and malaise. On admission, abdominal ultrasound and computed tomography revealed a 5.5-cm solitary pyogenic liver abscess in the right lobe. A percutaneous drain was placed, and empirical intravenous piperacillin-tazobactam was initiated.

By hospital day 4, the patient's temperature is 37.1°C (98.8°F), blood pressure is 128/78 mmHg, and pulse is 76/min. His leukocyte count has normalized to 7,500/mm³. He is tolerating a regular diet well. The percutaneous drain has had minimal output over the last 24 hours and is removed.

The abscess fluid culture grows *Escherichia coli* and *Bacteroides fragilis*. The antimicrobial susceptibility report shows the following results:

The patient is being prepared for discharge to complete a 4-week course of antimicrobial therapy. Which of the following is the most appropriate next step in management?

A 72-year-old man is brought to the emergency department for severe, worsening shortness of breath that began 6 hours ago. The patient has a history of essential hypertension, type 2 diabetes mellitus, and a 40-pack-year smoking history. He reports that his breathing became significantly worse shortly after he laid down to sleep. Current medications include metformin, lisinopril, and amlodipine. His temperature is 37.1°C (98.8°F), blood pressure is 172/96 mmHg, pulse is 112/min and regular, and respiratory rate is 28/min. Pulse oximetry shows an oxygen saturation of 88% on room air.

Physical examination reveals a patient in moderate respiratory distress, using accessory muscles of respiration. Jugular venous pulsation is visible 9 cm above the sternal angle. Chest auscultation reveals diffuse expiratory wheezes and bibasilar crackles extending halfway up the lung fields. Cardiac examination reveals a regular tachycardia with a prominent third heart sound (S3). Bilateral 2+ pitting edema is present in the lower extremities.

Arterial blood gas on room air reveals:
pH: $7.28$
$pCO_2$: $56 \text{ mmHg}$
$pO_2$: $54 \text{ mmHg}$
$HCO_3^-$: $25 \text{ mEq/L}$

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

Match the classic auscultatory physical exam findings described below with the most likely underlying valvular pathology.

A 45-year-old man is diagnosed with a pheochromocytoma after presenting with episodic headaches, sweating, and tachycardia. 24-hour urine fractionated metanephrines are significantly elevated, and an abdominal MRI reveals a 4-cm right adrenal mass. He is being prepared for curative management. Arrange the following interventions in the correct chronological order for the proper preoperative and definitive management of this patient.

A $58$-year-old man with a history of alcohol use disorder and cirrhosis is brought to the emergency department by his family due to a $2$-day history of diffuse abdominal pain, subjective fever, and worsening confusion. He also complains of mild shortness of breath. His temperature is $38.3^\circ\text{C}$ ($100.9^\circ\text{F}$), pulse is $105/\text{min}$, blood pressure is $105/65\text{ mmHg}$, and respirations are $18/\text{min}$. Physical examination reveals scleral icterus and spider angiomas on the chest. The abdomen is prominently distended with shifting dullness and diffuse mild tenderness, but there is no rebound or guarding. Neurologic examination demonstrates a bilateral flapping tremor when the arms are extended. A diagnostic paracentesis yields cloudy fluid. Ascitic fluid analysis shows a leukocyte count of $650/\text{mm}^3$ with $85\%$ neutrophils, and a total protein of $0.8\text{ g/dL}$. Serum creatinine is $1.3\text{ mg/dL}$. Which of the following is the most appropriate next step in management?

Match each of the following Hepatitis B serologic profiles with the most appropriate clinical state.

Match the following classic auscultatory and physical exam findings with their most likely underlying structural heart disease.

A 55-year-old man with a history of cavitary tuberculosis is brought to the emergency department coughing up approximately 800 mL of bright red blood over the last 6 hours. He is in severe respiratory distress, and his oxygen saturation is dropping rapidly. Arrange the following management steps in the most appropriate sequential order, from immediate life-saving resuscitation to definitive intervention.

A 42-year-old man presents to the urgent care clinic with a 2-day history of increasing redness, swelling, and pain on his right lower leg. He denies fevers, chills, or recent trauma, though he reports chronic itching between his toes. He has no significant past medical history and takes no medications. His temperature is 37.0°C (98.6°F), blood pressure is 118/76 mmHg, pulse is 72/min, and respiratory rate is 14/min. Physical examination of the right lower extremity reveals a warm, tender, and erythematous plaque with indistinct borders extending from the ankle to the mid-calf. There is no purulent exudate, ulceration, or fluctuance. Examination of the feet shows fissuring and maceration between the fourth and fifth digits. Which of the following is the most appropriate empiric treatment for this patient?

A $48$-year-old man is in the intensive care unit receiving mechanical ventilation for severe acute respiratory distress syndrome (ARDS). The ventilator is set to volume-control mode with a positive end-expiratory pressure (PEEP) of $15$ cm $H_2O$. Suddenly, the high-pressure alarm sounds. His oxygen saturation rapidly drops from $94\%$ to $78\%$, blood pressure falls to $70/40$ mm Hg, and heart rate increases to $145$/min. Physical examination reveals absent breath sounds over the right hemithorax, hyperresonance to percussion, and deviation of the trachea to the left. The jugular veins are distended. Arrange the following management steps in the most appropriate sequential order of priority for this patient.

Review the clinical vignettes and laboratory profiles below. Match each patient's clinical presentation and laboratory pattern to the most likely underlying primary endocrine diagnosis.

A 62-year-old man is hospitalized for right lower lobe pneumococcal pneumonia. After 72 hours of targeted intravenous antibiotic therapy, he has persistent fevers, tachypnea, and pleuritic chest pain. A chest radiograph reveals a new, moderate-to-large, free-flowing right-sided pleural effusion.

Assuming each subsequent intervention indicates the need for further escalation due to inadequate clinical resolution or complex fluid characteristics, arrange the following management steps in the most appropriate chronological sequence.

A 72-year-old woman is evaluated in the outpatient clinic for a 4-day history of frequent, watery, foul-smelling diarrhea and mild lower abdominal cramping. She has a medical history of chronic obstructive pulmonary disease (COPD) and diet-controlled type 2 diabetes mellitus. Three weeks ago, she completed a course of oral clindamycin for a dental abscess. She currently feels fatigued but denies shortness of breath, cough, or weight loss. Her temperature is 38.0°C (100.4°F), blood pressure is 118/76 mm Hg, and pulse is 92/min. Physical examination reveals mild, diffuse lower abdominal tenderness with hyperactive bowel sounds; there is no guarding or rebound tenderness. Which of the following is the most appropriate next step in management?

A 72-year-old woman is admitted to the hospital with a 2-day history of fever, severe right upper quadrant abdominal pain, and dark urine. Her temperature is 39.2°C (102.6°F), blood pressure is 94/60 mmHg, and pulse is 112/min. Physical examination reveals scleral icterus and marked right upper quadrant tenderness without rebound or guarding. Laboratory studies show a leukocyte count of 18,500/mm³ and a total bilirubin of 6.2 mg/dL. Abdominal ultrasound demonstrates a dilated common bile duct with an echogenic focus and acoustic shadowing. She is resuscitated with intravenous fluids and empirically started on intravenous piperacillin-tazobactam. An urgent endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy is performed, successfully removing a common bile duct stone and establishing biliary drainage. Two sets of blood cultures drawn upon admission subsequently grow *Escherichia coli*. Susceptibility testing reveals the organism is sensitive to ceftriaxone, ciprofloxacin, and trimethoprim-sulfamethoxazole, but resistant to amoxicillin. On hospital day 3, the patient is afebrile, hemodynamically stable, and her leukocytosis has resolved. Which of the following is the most appropriate next step in management regarding her antibiotic therapy?

A 62-year-old woman is evaluated in the outpatient clinic for a 3-day history of worsening shortness of breath, increased cough, and a change in sputum color from clear to dark yellow. She has a history of chronic obstructive pulmonary disease (COPD) and typically uses an albuterol inhaler as needed. Her temperature is 37.4°C (99.3°F), blood pressure is 130/82 mm Hg, pulse is 96/min, and respirations are 20/min. Pulse oximetry is 93% on room air. Physical examination reveals a barrel-shaped chest and a prolonged expiratory phase with scattered bilateral wheezing. There is no jugular venous distention, and no lower extremity edema is present. In addition to optimizing her bronchodilator therapy and initiating a short course of oral corticosteroids, which of the following is the most appropriate next step in management?

Following $2$ days of fever, progressive confusion, and abdominal pain, a $55$-year-old man is brought to the emergency department. He has a known history of alcohol-associated cirrhosis and diuretic-refractory ascites, for which he takes furosemide and spironolactone. His temperature is $38.6^\circ\text{C}$ ($101.5^\circ\text{F}$), blood pressure is $88/54$ mm Hg, pulse is $112$/min, and respirations are $24$/min. Physical examination reveals scleral icterus, a distended abdomen with shifting dullness, and diffuse abdominal tenderness to palpation. Asterixis is present.

Laboratory studies show:
Sodium: $140$ mEq/L
Potassium: $2.9$ mEq/L
Chloride: $105$ mEq/L
Bicarbonate: $20$ mEq/L
Blood urea nitrogen: $42$ mg/dL
Creatinine: $1.9$ mg/dL
Albumin: $1.0$ g/dL
Lactate: $5.2$ mmol/L

Arterial blood gas on room air:
pH: $7.51$
PaCO $_2$: $26$ mm Hg
PaO $_2$: $85$ mm Hg

Which of the following best characterizes this patient's primary acid-base disturbances?