Internal Medicine

A 42-year-old man presents to the emergency department with a 6-week history of chronic cough productive of blood-tinged sputum, drenching night sweats, fatigue, and an unintentional 6-kg (13-lb) weight loss. He recently immigrated to the United States from a country with a high incidence of tuberculosis. His temperature is 38.2°C (100.8°F), blood pressure is 118/76 mm Hg, pulse is 98/min, and respirations are 18/min. A portable chest radiograph performed in the triage area reveals a 3-cm cavitary lesion in the apical segment of the right upper lobe.

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

A 45-year-old man is hospitalized for the treatment of severe cellulitis of the right lower extremity. On admission, blood cultures were drawn, and he was started on empiric intravenous vancomycin and ceftriaxone. On hospital day 3, the patient is afebrile, and the erythema has significantly decreased. The blood cultures return positive for Staphylococcus aureus. Susceptibility testing shows the organism is resistant to penicillin but susceptible to oxacillin, cefazolin, and vancomycin. Which of the following is the most appropriate next step in antibiotic therapy?

A 65-year-old man develops severe right knee pain, swelling, and a temperature of 38.2°C (100.8°F) on postoperative day 3 following an uncomplicated inguinal hernia repair. His medical history is significant for hypertension and stage 3 chronic kidney disease. Examination reveals a markedly swollen, erythematous, and exquisitely tender right knee. Arthrocentesis yields cloudy yellow synovial fluid. Analysis shows a leukocyte count of 35,000/mm³ with 85% neutrophils. Polarized light microscopy reveals needle-shaped, negatively birefringent crystals. Gram stain shows no organisms. Which of the following is the most appropriate next step in management?

A 62-year-old man is brought to the emergency department by his daughter due to progressive lethargy, confusion, and generalized swelling over the past week. He has a history of hypertension, chronic obstructive pulmonary disease (COPD), and a pituitary macroadenoma treated with transsphenoidal resection two years ago. His medications include amlodipine and a fluticasone-vilanterol inhaler. On arrival, he is difficult to arouse. Temperature is 35.1°C (95.2°F), pulse is 48/min, respirations are 10/min, and blood pressure is 95/60 mm Hg. Pulse oximetry shows 92% on room air. Physical examination reveals periorbital puffiness, non-pitting edema of the lower extremities, and delayed relaxation phase of deep tendon reflexes. Pulmonary auscultation reveals diminished breath sounds bilaterally but no crackles. Laboratory results are as follows:

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

A 54-year-old man is hospitalized for a 3-day history of high fever, severe back pain, and chills. He has a history of type 2 diabetes mellitus and intravenous drug use. Temperature is 39.2°C (102.6°F), blood pressure is 110/70 mm Hg, and pulse is 112/min. Physical examination reveals point tenderness over the L3-L4 vertebrae and a new soft systolic murmur heard at the left lower sternal border. Blood cultures are drawn, and he is started empirically on intravenous vancomycin and piperacillin-tazobactam. Magnetic resonance imaging of the spine reveals L3-L4 osteomyelitis with an associated anterior epidural abscess. On day 3 of hospitalization, blood cultures grow Staphylococcus aureus. Susceptibility testing shows the organism is resistant to penicillin and susceptible to oxacillin, cefazolin, and vancomycin. Which of the following is the most appropriate next step in the patient's pharmacotherapy?

A 42-year-old woman is brought to the emergency department by her husband due to progressive confusion and lethargy over the past 2 days. She has also reported generalized weakness and dark urine. Her temperature is 38.1°C (100.6°F), blood pressure is 142/88 mmHg, pulse is 112/min, and respirations are 18/min. Physical examination reveals scleral icterus and scattered petechiae over her bilateral lower extremities. Neurologic examination shows a lethargic patient who is oriented to person only, with no focal motor or sensory deficits. Laboratory studies show the following:

A peripheral blood smear demonstrates numerous fragmented red blood cells (schistocytes). Which of the following is the most appropriate next step in management?

A 55-year-old man is evaluated in the hospital for a new-onset headache. He was admitted 5 days ago for a deep venous thrombosis of the right lower extremity and was started on intravenous unfractionated heparin. His temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $128/82\text{ mm Hg}$, pulse is $88/\text{min}$, and respirations are $16/\text{min}$. Physical examination is unremarkable, with no signs of active bleeding. Laboratory studies on admission showed a platelet count of $240,000/\mu\text{L}$. Today, his laboratory studies show a hemoglobin of $13.5\text{ g/dL}$, a leukocyte count of $7,500/\mu\text{L}$, and a platelet count of $105,000/\mu\text{L}$. Which of the following is the most appropriate next step in management?

Match each common respiratory pathogen causing community-acquired pneumonia with its classic clinical presentation, laboratory finding, or associated risk factor.

Match each clinical vignette describing a patient's presentation to the most likely systemic vasculitis diagnosis.

An 81-year-old woman is urgently evaluated on the medical-surgical unit for acute respiratory distress. She was admitted two days prior for treatment of pyelonephritis and bacteremia, initially receiving 3.5 liters of crystalloid resuscitation along with empiric intravenous piperacillin-tazobactam and vancomycin. Her past medical history includes heart failure with preserved ejection fraction, severe chronic obstructive pulmonary disease (COPD), and hypertension. Today, her blood cultures from admission are finalized, showing growth of Escherichia coli that is susceptible to ceftriaxone but resistant to ampicillin. Currently, she appears anxious and is breathing rapidly. Vital signs are temperature 37.0°C (98.6°F), blood pressure 152/88 mm Hg, heart rate 106/min, and respiratory rate 26/min. Oxygen saturation is 89% on room air. Examination shows jugular venous distention to 12 cm H2O. Auscultation reveals dullness to percussion at the bases with crackles extending halfway up the lung fields. Trace wheezing is also noted. Bilateral lower extremities exhibit 2+ pitting edema.

Laboratory studies drawn an hour ago show:
Leukocyte count: 11,200/mm³
Thyroid-stimulating hormone (TSH): 7.2 mU/L (normal: 0.5–5.0 mU/L)
Free thyroxine (T4): 1.1 ng/dL (normal: 0.9–1.7 ng/dL)

Arterial blood gas (room air):
pH: 7.22
PaCO2: 42 mm Hg
PaO2: 58 mm Hg
HCO3−: 17 mEq/L

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

An 82-year-old woman with a history of vascular dementia is evaluated on the surgical ward for acute confusion. She underwent a right total hip arthroplasty $24$ hours ago. Over the past $6$ hours, she has become highly agitated, disoriented, and reports seeing insects on the ceiling. She is currently receiving intravenous morphine as needed for postoperative pain. Her temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $132/78$ mmHg, pulse is $82$/min, and respirations are $14$/min. Physical examination reveals no suprapubic or costovertebral angle tenderness. The surgical incision is clean and intact. Laboratory studies show a leukocyte count of $8,400/\text{mm}^3$. A routine urinalysis obtained in the emergency department prior to surgery showed $25$ leukocytes/hpf, positive leukocyte esterase, and positive nitrites. The admission urine culture now grows $>10^5 \text{ CFU/mL}$ of *Escherichia coli* susceptible to ceftriaxone, ciprofloxacin, and trimethoprim-sulfamethoxazole. Which of the following is the most appropriate management of this patient's bacteriuria?

A 66-year-old man is brought to the emergency department by his family due to a severe, generalized headache, high fever, and progressive confusion over the past 24 hours. His medical history is significant for multiple myeloma, for which he is currently receiving maintenance chemotherapy. On arrival, his temperature is 39.4°C (102.9°F), blood pressure is 88/54 mmHg, pulse is 122/min, and respirations are 22/min. Physical examination reveals prominent nuchal rigidity and a new-onset right pronator drift. He is oriented only to his name. Arrange the following management steps in the most appropriate chronological order for this patient.

A $26$-year-old female patient is evaluated in the intensive care unit on postoperative day $4$ following a right total hip arthroplasty. Her past medical history is significant for Adult-Onset Still's disease, for which she is chronically managed with methotrexate and tocilizumab. She has developed acute lethargy, confusion, and a temperature of $39.9^\circ\text{C}$ ($103.8^\circ\text{F}$).

Physical examination reveals a blood pressure of $90/55 \text{ mmHg}$, heart rate of $132/\text{min}$, and respiratory rate of $26/\text{min}$. The surgical incision is clean, dry, and without erythema or fluctuance. Pulmonary and cardiac examinations are unremarkable. Abdominal examination reveals hepatosplenomegaly.

Laboratory studies are as follows:

Arterial blood gas (room air) shows $\text{pH}$ $7.52$, $\text{pCO}_2$ $26 \text{ mmHg}$, $\text{pO}_2$ $88 \text{ mmHg}$, and $\text{HCO}_3^-$ $21 \text{ mEq/L}$.

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

A 75-year-old man is brought to the emergency department for severe shortness of breath and worsening confusion over the past 24 hours. He has a history of severe chronic obstructive pulmonary disease, heart failure with preserved ejection fraction, and hypothyroidism. His medications include tiotropium, salmeterol, levothyroxine, and low-dose furosemide.

Temperature is 38.6°C (101.5°F), blood pressure is 92/58 mm Hg, pulse is 118/min, and respiratory rate is 26/min. Pulse oximetry shows 86% on room air. On examination, the patient is lethargic and oriented only to person. Jugular venous pressure is 5 cm H₂O. Chest auscultation reveals crackles in the left lower lung field and diffuse expiratory wheezing. Heart sounds are tachycardic but regular. The extremities are warm with brisk capillary refill, and there is no peripheral edema.

Laboratory results:
Sodium: 135 mEq/L
Potassium: 4.5 mEq/L
Chloride: 98 mEq/L
Bicarbonate: 12 mEq/L
Blood urea nitrogen: 48 mg/dL
Serum creatinine: 2.3 mg/dL
Serum lactate: 6.2 mmol/L
Leukocyte count: 18,500/mm³
TSH: 0.1 µU/mL (Normal: 0.4-4.0 µU/mL)
Free T4: 1.1 ng/dL (Normal: 0.9-1.7 ng/dL)

Arterial blood gas on room air:
pH: 7.18
PaCO₂: 33 mm Hg
PaO₂: 58 mm Hg

Chest radiograph shows a left lower lobe consolidation. A rapid multiplex PCR panel of a tracheal aspirate is positive for *Streptococcus pneumoniae* and negative for all common resistance genes.

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

Match each of the following patient vignettes, representing complex hemostatic disruptions, to the most accurate underlying pathophysiologic mechanism or diagnosis.

Match each clinical scenario describing a recent infectious exposure or early clinical presentation with the most appropriate targeted empiric therapy or post-exposure prophylaxis.

During multidisciplinary rounds in the intensive care unit, a clinical pharmacist raises a concern regarding a patient being treated for infective endocarditis. The patient was admitted 8 days ago after presenting with a one-month history of fatigue, low-grade fevers, and painful, erythematous nodules on the distal fingers. Initial blood cultures grew *Enterococcus faecalis* that was widely susceptible, including to ampicillin, vancomycin, and high-level gentamicin. Echocardiography confirmed a 1.2-cm vegetation on the native mitral valve. The patient was promptly started on intravenous ampicillin and scheduled doses of intravenous gentamicin. Today, the patient is afebrile and hemodynamically stable. However, routine laboratory studies reveal a serum creatinine level of 2.6 mg/dL, an increase from 0.8 mg/dL on admission. Urinalysis demonstrates muddy brown casts. Which of the following is the most appropriate modification to this patient's pharmacotherapy?

A $28$-year-old woman presents to the clinic complaining of worsening fatigue, exertional dyspnea, and yellowing of her eyes over the past two weeks. Her past medical history is significant for systemic lupus erythematosus (SLE), which has been well-controlled on hydroxychloroquine. Vital signs are within normal limits except for a heart rate of $112$/min. Physical examination reveals scleral icterus and pale conjunctivae. The spleen is palpable $3$ cm below the left costal margin. Laboratory studies reveal the following:

A peripheral blood smear demonstrates normochromic red blood cells, marked polychromasia, and numerous spherocytes. No schistocytes are seen. Which of the following is the most appropriate next step to establish the diagnosis?

A $22$-year-old man with type $1$ diabetes mellitus is brought to the emergency department with a $2$-day history of nausea, vomiting, and abdominal pain. He recently had a respiratory infection and missed his last several doses of insulin. On presentation, he is lethargic. Vital signs show a heart rate of $122/\text{min}$, blood pressure of $90/60 \text{ mm Hg}$, and respiratory rate of $28/\text{min}$ with deep, rapid breaths. Laboratory studies reveal:

- Serum glucose: $480 \text{ mg/dL}$
- Serum sodium: $132 \text{ mEq/L}$
- Serum bicarbonate: $12 \text{ mEq/L}$
- Arterial pH: $7.15$
- Urinalysis: $+++$ ketones

A complete metabolic panel has been drawn, but the serum potassium result is currently pending.

Arrange the following critical steps in the management of this patient's diabetic ketoacidosis in the correct sequential order.

A 34-year-old woman is evaluated in the outpatient clinic for progressive fatigue, a $4.5\text{ kg}$ ($10\text{ lb}$) weight gain, and feeling persistently cold over the past 8 months. She also reports that she has not resumed menstruating since giving birth to her third child 14 months ago. The delivery was complicated by severe postpartum hemorrhage requiring emergent blood transfusions. Her blood pressure is $92/58\text{ mm Hg}$, and her pulse is $54/\text{min}$. Physical examination reveals pale, dry skin and a delayed relaxation phase of the deep tendon reflexes.

Laboratory studies:
- Sodium: $132\text{ mEq/L}$
- Potassium: $4.2\text{ mEq/L}$
- Thyroid-stimulating hormone (TSH): $1.6\ \mu\text{U/mL}$ (normal: $0.5-5.0\ \mu\text{U/mL}$)
- Free thyroxine (T4): $0.3\text{ ng/dL}$ (normal: $0.9-1.7\text{ ng/dL}$)

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