Internal Medicine

A critical care physician is reviewing the microbiological data for a patient admitted with a severe burn injury. One week into the hospitalization, the patient developed a new-onset fever of $39.4^\circ\text{C}$ ($102.9^\circ\text{F}$) and hypotension requiring vasopressor support. Blood cultures were obtained from a central venous catheter and a peripheral vein, and empiric antimicrobial therapy with intravenous vancomycin, cefepime, and gentamicin was instituted.

Today, both sets of blood cultures are positive for *Klebsiella pneumoniae*. The microbiology laboratory reports that the isolate is susceptible to ceftriaxone, cefepime, piperacillin-tazobactam, and meropenem, but resistant to ampicillin. The patient's clinical status has stabilized significantly; the fever has resolved, and vasopressor support was discontinued yesterday. Based on the principles of antimicrobial stewardship, which of the following is the most appropriate modification to this patient's pharmacologic regimen?

Match each gastrointestinal or hepatobiliary clinical scenario with the most appropriate antimicrobial stewardship strategy or treatment plan.

A 46-year-old man is evaluated in the intensive care unit on hospital day 3 for persistent fever and abdominal pain. He was admitted 3 days ago with severe acute pancreatitis secondary to alcohol use disorder. Since admission, he has been receiving aggressive intravenous fluid resuscitation and intravenous hydromorphone. Today, his temperature is 38.9°C (102.0°F), blood pressure is 112/70 mm Hg, pulse is 118/min, and respirations are 22/min. Physical examination reveals a distended abdomen with marked epigastric tenderness and diminished bowel sounds. Laboratory studies show a leukocyte count of 18,500/mm³ with 12% bands. A repeat CT scan of the abdomen with intravenous contrast demonstrates nonenhancement of approximately 40% of the pancreatic parenchyma and several large peripancreatic fluid collections. There is no evidence of gas within the fluid collections or the pancreatic bed. Which of the following is the most appropriate next step in management?

A $58$-year-old man comes to the physician due to a $2$-week history of worsening fatigue, generalized weakness, nausea, and decreased libido. He was diagnosed with metastatic melanoma $12$ weeks ago and has been receiving treatment with nivolumab and ipilimumab. Temperature is $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure is $102/64$ mm Hg, and pulse is $68$/min. Physical examination shows a mildly delayed relaxation phase of the deep tendon reflexes. There is no abnormal skin hyperpigmentation. Laboratory studies show:

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

A 68-year-old man is admitted to the hospital with a 2-day history of progressively worsening, crampy abdominal pain, abdominal distension, and multiple episodes of bilious vomiting. He reports not having passed flatus or stool for the past 24 hours. His past medical history is significant for hypertension and an open appendectomy 15 years ago.

Vital signs are:
Temperature: $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$)
Blood pressure: $105/65\text{ mmHg}$
Heart rate: $110/\text{min}$
Respiratory rate: $18/\text{min}$

Physical examination reveals a markedly distended and tympanitic abdomen. Bowel sounds are high-pitched and hyperactive. There is diffuse, mild tenderness to palpation, but no rebound tenderness or abdominal wall rigidity.

Laboratory results show:
Leukocyte count: $9,500/\text{mm}^3$
Serum sodium: $138\text{ mEq/L}$
Serum potassium: $3.2\text{ mEq/L}$
Serum chloride: $96\text{ mEq/L}$
Serum bicarbonate: $29\text{ mEq/L}$
Blood urea nitrogen: $48\text{ mg/dL}$
Serum creatinine: $1.9\text{ mg/dL}$ (Baseline: $1.0\text{ mg/dL}$)
Lactic acid: $1.1\text{ mmol/L}$ (Normal: $0.5 - 2.2\text{ mmol/L}$)

Upright abdominal radiography reveals multiple dilated loops of small intestine with prominent air-fluid levels and an absence of colonic gas.

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

A 59-year-old woman arrives at the emergency department via ambulance with acute, severe respiratory distress. She awoke from sleep two hours ago gasping for air. Her medical history includes hypertension, diet-controlled type 2 diabetes mellitus, and a 35-pack-year smoking history. She has not seen a physician in three years and does not take any daily medications. On arrival, the patient is diaphoretic, sitting bolt upright, and using accessory muscles of respiration. She is unable to speak in full sentences. Vital signs show a temperature of $37.1^\circ\text{C}$, blood pressure of $220/115$ mm Hg, pulse of $128$/min, and respiratory rate of $34$/min. Pulse oximetry shows an oxygen saturation of $83\%$ on room air. Physical examination reveals an estimated jugular venous pressure of $12$ cm H $_2$ O. Chest auscultation demonstrates loud, diffuse expiratory wheezing bilaterally with a prolonged expiratory phase; no crackles are appreciated. Cardiac examination reveals a regular tachycardia with a prominent S4 gallop. There is no peripheral edema. A portable chest radiograph shows prominent pulmonary vasculature and peribronchial cuffing, without focal consolidation. Arterial blood gas analysis on room air reveals:

pH: $7.14$
PaCO $_2$: $65$ mm Hg
PaO $_2$: $52$ mm Hg
HCO $_3^-$: $21$ mEq/L

The patient is immediately placed on noninvasive positive-pressure ventilation (NIPPV). Which of the following is the most appropriate next step in pharmacologic management?

A 32-year-old woman is brought to the emergency department by her husband due to confusion, severe agitation, and palpitations. She has a history of hyperthyroidism but stopped taking her medications three months ago. On presentation, her temperature is $39.4^\circ\text{C}$ ($103^\circ\text{F}$), blood pressure is $150/70\text{ mm Hg}$, and heart rate is $148/\text{min}$ and irregular. Physical examination reveals a staring gaze, a diffusely enlarged and non-tender thyroid gland, and a fine tremor in both hands. An electrocardiogram shows atrial fibrillation with a rapid ventricular response. A clinical diagnosis of thyroid storm is made. Arrange the following interventions in the most appropriate chronological sequence for the management of this patient, from initial acute stabilization to definitive long-term therapy.

A $28$-year-old man comes to the physician for a new patient evaluation. He has no physical complaints. When asked about medication use, he admits to self-administering intramuscular testosterone for the past $2$ years to assist with bodybuilding. He denies fatigue, heat or cold intolerance, or changes in bowel habits. Vital signs are within normal limits. Physical examination reveals a heavily muscled physique, scattered cystic acne on the shoulders, and bilateral testicular atrophy. The thyroid gland is palpably normal in size without nodules.

Routine laboratory screening is performed, and results show:

Based on the laboratory findings, which of the following is the most appropriate next step in management?

An evaluating physician assesses a 31-year-old female in the urgent care clinic. She reports a two-week duration of severe joint pain affecting her wrists and knees, accompanied by daily fevers. She states her temperature consistently spikes to $39.5^{\circ}\text{C}$ ($103.1^{\circ}\text{F}$) in the late afternoon and returns to normal by the following morning. During these febrile episodes, she notices a faint, salmon-colored rash on her trunk that completely resolves once the fever breaks. Her medical history is notable for bipolar disorder, which is currently managed with lithium and a recently added selective serotonin reuptake inhibitor.

Vital signs are temperature $39.4^{\circ}\text{C}$ ($102.9^{\circ}\text{F}$), blood pressure $118/76\text{ mm Hg}$, pulse $112/\text{min}$, and respirations $18/\text{min}$. Physical examination confirms a macular, salmon-colored rash on the chest and abdomen. The wrists and knees exhibit mild effusions and tenderness to palpation bilaterally.

Laboratory studies show:

Blood and urine cultures obtained 48 hours ago demonstrate no growth.

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

A $75$-year-old man is evaluated in the intensive care unit due to a sudden deterioration in his clinical status. He was admitted $14$ days ago for an open repair of a ruptured abdominal aortic aneurysm. His recovery has been complicated by prolonged mechanical ventilation and reliance on total parenteral nutrition. Over the past $3$ days, he developed progressive abdominal distension and high-volume bilious drainage from a nasogastric tube. He has not had a bowel movement for a week.

This morning, his temperature spiked to $39.4^\circ\text{C}$ ($102.9^\circ\text{F}$). His blood pressure dropped to $82/50 \text{ mmHg}$, and his heart rate is $122/\text{min}$. He is receiving a continuous infusion of norepinephrine, and broad-spectrum intravenous antibiotics (piperacillin-tazobactam) have been initiated.

Physical examination demonstrates a markedly distended and tympanitic abdomen with absent bowel sounds. There is focal tenderness to deep palpation in the right upper quadrant.

Laboratory studies:
Leukocyte count: $25,500/\text{mm}^3$ (with $15\%$ bands)
Hemoglobin: $9.8 \text{ g/dL}$
Total bilirubin: $3.1 \text{ mg/dL}$
Alkaline phosphatase: $340 \text{ U/L}$
Aspartate aminotransferase (AST): $92 \text{ U/L}$
Lactate: $4.8 \text{ mmol/L}$

A portable abdominal radiograph shows diffuse dilation of both the small and large intestines without a discrete transition point. No pneumoperitoneum is present. A bedside right upper quadrant ultrasound reveals a distended gallbladder with a wall thickness of $7 \text{ mm}$, pericholecystic fluid, and no intraluminal echogenic shadowing. The common bile duct diameter is $4 \text{ mm}$.

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

A 48-year-old man is evaluated in the hospital for new-onset chest discomfort and lightheadedness. He was admitted 5 days ago for methicillin-susceptible *Staphylococcus aureus* (MSSA) bacteremia and suspected infective endocarditis. He has a history of intravenous drug use. A transthoracic echocardiogram on admission showed a 1.2-cm vegetation on the right coronary cusp of the aortic valve with mild aortic regurgitation. He was started on targeted therapy with intravenous oxacillin. Today, he reports feeling weak and dizzy when sitting up in bed, along with a vague, substernal tightness. His temperature is 38.4°C (101.1°F), blood pressure is 102/60 mm Hg, and pulse is 58/min. Physical examination reveals an early diastolic decrescendo murmur at the left sternal border. The lungs have fine bibasilar crackles. An electrocardiogram is obtained which shows a sinus rhythm with a PR interval of 0.28 seconds and a new left bundle branch block. Which of the following is the most appropriate next step in management?

A 72-year-old man is evaluated on hospital day 3 for discharge planning. He was initially admitted with fever, productive cough, and left-sided pleuritic chest pain. Chest radiography on admission demonstrated a dense left lower lobe consolidation. He was started on empiric intravenous ceftriaxone and azithromycin. Two sets of blood cultures drawn upon presentation have grown *Streptococcus pneumoniae*. Antimicrobial susceptibility testing is reported as follows:

The patient's clinical status has markedly improved. He has been afebrile for 24 hours, maintains an oxygen saturation of 96% on room air, and is tolerating an oral diet. His medical history includes hypertension and benign prostatic hyperplasia. He has no known drug allergies. The plan is to discharge the patient to complete a total 7-day course of antibiotics at home. Which of the following is the most appropriate oral antibiotic to prescribe for discharge?

A 54-year-old man is evaluated in the hospital on the third day of his admission for community-acquired pneumonia. He was initially started on empiric therapy with intravenous ceftriaxone and azithromycin. Today, the patient reports feeling much better and has a good appetite. His temperature is 37.1°C (98.8°F), blood pressure is 124/78 mm Hg, pulse is 76/min, and respiratory rate is 16/min. He is tolerating a regular diet. Blood cultures drawn on admission are negative. Sputum cultures have grown *Streptococcus pneumoniae*. Susceptibility testing indicates the isolate is sensitive to penicillin, amoxicillin, levofloxacin, and vancomycin. Which of the following is the most appropriate next step in this patient's management?

A 74-year-old man is evaluated in the hospital for severe, sudden-onset abdominal pain. He was admitted 3 days ago for shortness of breath and lower extremity edema, for which he has been receiving intravenous furosemide. His medical history is significant for ischemic cardiomyopathy, persistent atrial fibrillation, and chronic obstructive pulmonary disease (COPD). On examination today, he appears in acute distress. His temperature is 37.8°C (100°F), blood pressure is 105/65 mm Hg, pulse is 118/min and irregularly irregular, and respirations are 24/min. The abdomen is moderately distended but remarkably soft and non-tender to deep palpation; bowel sounds are hypoactive.

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

A 68-year-old man with a history of metastatic castrate-resistant prostate cancer is evaluated in the emergency department for progressive weakness in his legs over the past 3 days. He reports a 'tight band' sensation around his mid-abdomen and states he has been unable to urinate for the last 14 hours. On physical examination, temperature is 36.9°C (98.4°F), blood pressure is 155/90 mmHg, heart rate is 88/min, and respiratory rate is 14/min. Neurologic examination reveals 2/5 motor strength in the bilateral lower extremities, absent patellar and Achilles reflexes, and decreased sensation to pinprick below the umbilicus. Palpation of the lower abdomen reveals a distended, firm bladder.

Arrange the following management steps in the most appropriate chronological order for this patient.

A 71-year-old woman is evaluated on the medical ward due to acute-onset confusion and progressively worsening shortness of breath. She was admitted 3 days ago for a severe exacerbation of chronic obstructive pulmonary disease (COPD). She has a history of ischemic cardiomyopathy (ejection fraction 40%). Sputum cultures collected on admission have just returned positive for *Moraxella catarrhalis*, which is sensitive to amoxicillin. She is currently receiving intravenous ceftriaxone, nebulized bronchodilators, and systemic glucocorticoids.

Current vital signs include a temperature of $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), blood pressure of $138/85\text{ mm Hg}$, pulse of $108/\text{min}$, and respiratory rate of $26/\text{min}$. On physical examination, the patient is somnolent but arousable to verbal stimuli. Lung auscultation reveals prolonged expiration with bilateral wheezing. The jugular venous pressure is $7\text{ cm H}_2\text{O}$ (normal $<8\text{ cm H}_2\text{O}$). Heart sounds are normal. There is no peripheral edema.

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

A 71-year-old retired teacher with a significant smoking history and essential hypertension is evaluated in the emergency department for worsening respiratory distress over the past 48 hours. She describes a sensation of 'drowning' when she tries to sleep and has resorted to sitting upright in a chair overnight. She has a cough producing frothy sputum. Current medications include lisinopril and hydrochlorothiazide. Her temperature is 37.0°C (98.6°F), blood pressure is 172/98 mmHg, pulse is 112/min, and respiratory rate is 26/min. Oxygen saturation is 88% on room air. Physical examination reveals prominent jugular veins when sitting at a 45-degree angle. Lung auscultation yields diffuse expiratory wheezing and prominent crackles in the lower lung fields bilaterally. Cardiac examination reveals a regular tachycardia with a distinct third heart sound (S3). A chest radiograph demonstrates bilateral interstitial infiltrates, prominent superior pulmonary vessels, and an enlarged cardiac silhouette. Which of the following is the most appropriate initial pharmacotherapy for this patient?

Match each classic auscultatory finding with its most likely underlying valvular pathology.

Match each patient's adrenal and pituitary laboratory profile with the most likely underlying pathophysiologic diagnosis.

A retired 62-year-old teacher visits an urgent care clinic reporting a one-week history of progressively worsening difficulty breathing. She notes a new, persistent cough and states she has been forced to sleep in her living room recliner for the past three nights to avoid feeling suffocated when lying flat. Her medical background is significant for well-controlled type 2 diabetes mellitus and long-standing hypertension. She smoked cigarettes briefly in her twenties but quit over 30 years ago.

Current vital signs include a temperature of 37.0°C (98.6°F), blood pressure of 162/94 mmHg, heart rate of 92/min, and respiratory rate of 22/min. Pulse oximetry displays 94% on ambient air.

During the physical examination, the physician observes distended jugular veins when the patient is seated at a 45-degree angle. Auscultation of the posterior lung fields reveals prominent bilateral basilar crackles. Symmetrical, pitting edema is present in both ankles.

A point-of-care chest radiograph demonstrates an enlarged cardiac silhouette and bilateral pulmonary vascular congestion. Laboratory studies, including a complete blood count, basic metabolic panel, and a thyroid-stimulating hormone (TSH) level of 1.8 mU/L, are within normal limits.

What is the most appropriate initial pharmacologic therapy for this patient?