Internal Medicine

During a routine prenatal visit at 27 weeks gestation, a 29-year-old gravida 1, para 0 reports increasing fatigue, swelling in her lower extremities, and intermittent pain in her wrists and metacarpophalangeal joints over the past two weeks. She was diagnosed with systemic lupus erythematosus four years ago, which has been quiescent on a regimen of hydroxychloroquine. Her home blood pressure readings have trended upward to approximately 145/90 mm Hg over the last several days. Vital signs today include a temperature of 37.1 C (98.8 F), blood pressure of 152/96 mm Hg, and pulse of 84/min. Physical examination confirms 2+ pitting edema extending to the mid-calves and mild synovitis in the hands. Urinalysis demonstrates 3+ proteinuria but is negative for leukocyte esterase and nitrites. The medical team is debating whether her presentation represents a primary hypertensive disorder of pregnancy or an exacerbation of her underlying autoimmune diathesis. Which of the following laboratory findings would most strongly point toward an autoimmune exacerbation?

A 58-year-old woman with a 10-year history of severe rheumatoid arthritis presents to the clinic with worsening fatigue over the past few months. Her joint pain has also been poorly controlled recently despite her current medication regimen. Vital signs are within normal limits. Physical examination reveals swollen, tender metacarpophalangeal and proximal interphalangeal joints bilaterally.

Laboratory studies show the following:

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

A 72-year-old man is brought to the emergency department by his daughter due to progressive lethargy, severe constipation, and deep lower back pain over the past week. He has a history of chronic obstructive pulmonary disease (COPD) and heart failure with preserved ejection fraction. The patient's brother is his legally appointed healthcare proxy, but the daughter is currently present and demands immediate aggressive interventions.

Upon arrival, a triage nurse accidentally administers 1 liter of 5% Dextrose in water (D5W) instead of the ordered isotonic saline. The daughter becomes furious upon realizing this and demands the nurse be fired immediately.

Temperature is 37.1°C (98.8°F), blood pressure is 115/75 mmHg, pulse is 105/min, and respirations are 16/min. Mucous membranes are dry, and he has diminished skin turgor. Neurologic examination reveals confusion and disorientation. Chest X-ray shows hyperinflated lungs. Lung auscultation reveals mild bilateral basilar crackles, which are unchanged from his baseline exams.

Laboratory studies are as follows:

A urine culture obtained two days ago at an outpatient clinic has just resulted, growing >100,000 CFU/mL of *Escherichia coli* that is sensitive to nitrofurantoin and cephalexin, but resistant to ampicillin.

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

A 68-year-old man with a history of benign prostatic hyperplasia is admitted to the hospital with fever, severe left flank pain, and dysuria. His temperature is $39.4^\circ\text{C}$ ($102.9^\circ\text{F}$), blood pressure is $100/60\text{ mmHg}$, and heart rate is $110\text{/min}$. Laboratory studies show a leukocyte count of $18,000\text{/mm}^3$. He is empirically started on intravenous piperacillin-tazobactam and intravenous fluids.

On hospital day 3, the patient is clinically improved and afebrile. Blood and urine cultures drawn at admission both grow *Enterobacter cloacae*.

Antimicrobial susceptibility testing of the isolate reveals the following:
- Ampicillin: Resistant
- Cefazolin: Resistant
- Ceftriaxone: Sensitive (MIC $\leq 1\text{ }\mu\text{g/mL}$)
- Cefepime: Sensitive (MIC $\leq 1\text{ }\mu\text{g/mL}$)
- Piperacillin-tazobactam: Sensitive (MIC $4\text{ }\mu\text{g/mL}$)
- Meropenem: Sensitive (MIC $\leq 0.25\text{ }\mu\text{g/mL}$)

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

A 76-year-old woman is evaluated in the hospital on day 5 of her admission due to an episode of hypotension and altered mental status. She was initially admitted for a severe COPD exacerbation and has been receiving systemic glucocorticoids, nebulized bronchodilators, and prophylactic enoxaparin. An indwelling Foley catheter was placed on admission due to urinary retention and has remained in place.

Today (Day 5), her temperature is $38.3^\circ\text{C}$ ($100.9^\circ\text{F}$), blood pressure is $88/56\text{ mmHg}$, heart rate is $112\text{/min}$, and respiratory rate is $22\text{/min}$. Physical examination reveals a lethargic patient. The abdomen is soft and non-tender, and there is no costovertebral angle tenderness. Laboratory findings show a leukocyte count of $16,500\text{/mm}^3$. A urinalysis obtained from the Foley catheter port shows $25\text{ WBCs/hpf}$ and positive leukocyte esterase, but negative nitrites.

Blood and urine cultures are drawn. The patient receives intravenous fluid resuscitation, and empiric intravenous vancomycin and cefepime are initiated.

Two days later (Day 7), the patient is clinically improved, her mental status has returned to baseline, she is hemodynamically stable off fluids, and she is afebrile. Blood cultures show no growth at 48 hours. The urine culture grows $>10^5\text{ CFU/mL}$ of *Enterococcus faecalis*.

Antimicrobial susceptibility testing for the *E. faecalis* isolate demonstrates the following:
- Ampicillin: Susceptible
- Cefepime: Resistant
- Ciprofloxacin: Resistant
- Linezolid: Susceptible
- Vancomycin: Susceptible

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

An emergency department physician evaluates a 62-year-old female patient reporting severe, progressively worsening mid-back pain over the past week. The pain is particularly severe in the supine position and frequently awakens her from sleep. Today, she developed bilateral lower extremity weakness and has been unable to urinate for the past 12 hours. Her medical history includes estrogen receptor-positive breast cancer, for which she underwent lumpectomy, radiation, and hormonal therapy five years ago.

Vital signs are within normal limits. Neurologic examination demonstrates $3/5$ motor strength in both legs, decreased pain and temperature sensation below the umbilicus, and hyperreflexia at the patellar and Achilles tendons. Anal sphincter tone is diminished. Bladder ultrasound reveals a post-void residual volume of $600\text{ mL}$.

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

A female patient with a longstanding history of erosive polyarthritis and frequent episodes of podagra is brought to the emergency department by her family due to mucosal bleeding, diffuse bruising, and profound weakness. Three weeks prior, her rheumatologist discontinued her tumor necrosis factor inhibitor due to loss of efficacy and initiated a new oral disease-modifying antirheumatic drug. Her home medications also include a daily prophylactic agent to prevent her foot flares. Vital signs are within normal limits, though she appears pale and fatigued. Laboratory analysis reveals:

Pharmacologic inhibition of which of the following enzymes most directly caused this patient's hematologic abnormalities?

A 68-year-old man with a history of chronic obstructive pulmonary disease (COPD) is hospitalized for induction chemotherapy for newly diagnosed acute myeloid leukemia. On day 8 of his admission, his absolute neutrophil count is $200/\text{mm}^3$ and his hemoglobin is $6.2\text{ g/dL}$. He is afebrile and hemodynamically stable. He is prescribed a transfusion of two units of packed red blood cells.

Two hours into the transfusion, he develops acute-onset severe dyspnea, tachypnea, and a dry cough.

Vital signs are as follows:
- Temperature: $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$)
- Blood pressure: $178/92\text{ mmHg}$
- Heart rate: $112/\text{min}$
- Respiratory rate: $26/\text{min}$
- $\text{SpO}_2$: $86\%$ on room air

Physical examination reveals a frail man in moderate respiratory distress using accessory muscles of respiration. Jugular venous pressure is $12\text{ cm H}_2\text{O}$. Chest auscultation reveals diffuse, prolonged expiratory wheezing with faint bibasilar crackles.

Arterial blood gas analysis on room air shows:
- pH: $7.28$
- $\text{pCO}_2$: $56\text{ mmHg}$
- $\text{pO}_2$: $54\text{ mmHg}$
- $\text{HCO}_3^-$: $25\text{ mEq/L}$

Routine morning laboratory results (drawn prior to the transfusion) show:
- Sodium: $138\text{ mEq/L}$
- Potassium: $4.2\text{ mEq/L}$
- Chloride: $102\text{ mEq/L}$
- Bicarbonate: $24\text{ mEq/L}$
- Blood urea nitrogen: $18\text{ mg/dL}$
- Creatinine: $0.9\text{ mg/dL}$
- TSH: $0.2\text{ }\mu\text{U/mL}$ (Normal: $0.4–4.0$)
- Free T4: $0.7\text{ ng/dL}$ (Normal: $0.9–1.7$)

The transfusion is immediately halted, and the patient is placed on supplemental oxygen via a non-rebreather mask. Which of the following is the most appropriate next step in the management of this patient?

An 82-year-old woman who resides in a skilled nursing facility is brought to the clinic for a routine wellness visit. She has a history of mild vascular dementia and type 2 diabetes mellitus. The patient is at her baseline cognitive function and reports no fever, chills, dysuria, increased urinary urgency, or abdominal pain. Vital signs are temperature 37.0°C (98.6°F), blood pressure 138/82 mmHg, and pulse 78/min. The abdomen is non-tender and there is no costovertebral angle tenderness. As part of a general protocol by the nursing facility, a urinalysis and urine culture were obtained prior to the visit. The urinalysis shows moderate leukocyte esterase and positive nitrites. The urine culture grows >100,000 CFU/mL of Escherichia coli. Which of the following is the most appropriate next step in management?

A $78$-year-old man who resides in a skilled nursing facility is evaluated for acute-onset severe pain and swelling in his right knee that began $24$ hours ago. He has a history of hypertension, diet-controlled type 2 diabetes mellitus, and advanced chronic kidney disease with a baseline serum creatinine of $2.6 \text{ mg/dL}$. Vital signs are within normal limits except for a temperature of $37.7^\circ\text{C}$ ($99.9^\circ\text{F}$). Physical examination reveals a warm, erythematous, and swollen right knee with a moderate effusion. Range of motion is severely limited by pain. Arthrocentesis yields $4 \text{ mL}$ of cloudy, yellow synovial fluid. Analysis shows a leukocyte count of $32,000/\mu\text{L}$ with $90\%$ neutrophils. Polarized light microscopy demonstrates rhomboid-shaped crystals with weak positive birefringence. Gram stain reveals no organisms. Which of the following is the most appropriate next step in management?

A 68-year-old man with a history of metastatic prostate cancer presents to the emergency department with 2 days of progressively worsening lower back pain and new-onset bilateral leg weakness. He also reports difficulty initiating urination for the past 12 hours. Vital signs are within normal limits. Physical examination reveals reduced motor strength (3/5) in both lower extremities, hyperreflexia at the knees and ankles, and decreased sensation to pinprick below the umbilicus. Arrange the following management steps in the most appropriate chronological sequence for this patient.

A 68-year-old man is evaluated in the hospital on day 3 of admission for community-acquired pneumonia. His medical history is significant for hypertension and osteoarthritis. On admission, he presented with a temperature of 38.9°C (102.0°F), a productive cough, and a right lower lobe consolidation on chest radiography. He was started on empiric therapy with intravenous ceftriaxone and oral azithromycin.

Sputum and blood cultures obtained on admission have now finalized, both growing *Streptococcus pneumoniae*. Susceptibility testing of the isolate demonstrates the following:

Today, the patient reports feeling much better. He has been afebrile for the past 28 hours. His heart rate is 78/min, blood pressure is 128/82 mmHg, and respiratory rate is 16/min. Oxygen saturation is 96% on room air. He is tolerating a regular diet without difficulty. Which of the following is the most appropriate next step in his antimicrobial management?

A 24-year-old man presents to the clinic evaluating a 10-month history of insidious-onset lower back pain. He notes that the pain is worst upon awakening, is accompanied by profound stiffness lasting up to two hours, and significantly improves after physical activity. He has no other medical conditions and takes no medications. His vital signs are within normal limits. Physical examination reveals tenderness to palpation over the sacroiliac joints and reduced forward flexion of the lumbar spine (abnormal modified Schober test).

Arrange the following interventions in the correct chronological sequence for the standard diagnostic workup and stepwise medical management of this patient's suspected condition. Assume that initial diagnostic imaging is inconclusive (necessitating a more sensitive modality to confirm the diagnosis) and that the patient later requires escalation of maintenance therapy due to an inadequate clinical response to first-line pharmacotherapy.

An adult female patient is evaluated in the acute care clinic approximately $1$ hour following the intentional ingestion of a large, unknown quantity of acetaminophen. On initial assessment, she is fully alert, cooperative, and reports no symptoms. Hemodynamic parameters are stable. Arrange the following clinical interventions in the most appropriate chronological sequence for the evaluation and treatment of this patient.

Match each patient's clinical presentation with the most appropriate first-line pharmacotherapy.

A 61-year-old man is brought to the emergency department due to a three-day history of progressively worsening breathlessness, orthopnea, and a cough productive of clear sputum. His past medical history is significant for severe chronic obstructive pulmonary disease (COPD), ischemic cardiomyopathy with a left ventricular ejection fraction of $35\%$, and diet-controlled type 2 diabetes mellitus. Vital signs show a temperature of $37.1^\circ$ C ($98.8^\circ$ F), pulse of 112/min, blood pressure of 155/92 mm Hg, and respiratory rate of 26/min. Pulse oximetry demonstrates an oxygen saturation of $86\%$ on room air. Physical examination reveals neck veins distended to 11 cm $H_2O$ while the patient is seated at a 45-degree angle. Auscultation of the lungs demonstrates prominent bibasilar crackles without any wheezing. Cardiac examination reveals a regular tachycardia and an $S_3$ gallop. The lower extremities exhibit $2+$ pitting edema bilaterally.

Laboratory results are as follows:

An arterial blood gas on room air shows a pH of 7.26, a $PaCO_2$ of 65 mm Hg, and a $PaO_2$ of 52 mm Hg.

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

A 62-year-old woman is evaluated for progressively worsening fatigue and dyspnea on exertion over the past 3 months. She has followed a strict vegan diet for the past 5 years and does not take any nutritional supplements. Physical examination reveals pale conjunctivae, a smooth and red tongue, and decreased vibratory sensation in the lower extremities bilaterally. Laboratory studies show:

Which of the following additional laboratory findings is most likely to be present in this patient?

Match each clinical presentation involving the hands and joints to the most likely rheumatologic diagnosis.

A 54-year-old man comes to the office due to worsening redness and swelling of his left lower leg over the past 48 hours. He reports no fever, chills, or systemic symptoms. His medical history includes hypertension and diet-controlled type 2 diabetes mellitus. Vital signs show a temperature of 37.2°C (99.0°F), blood pressure of 130/80 mm Hg, and heart rate of 78/min. Physical examination of the left lower extremity reveals a 10-cm area of poorly demarcated erythema, warmth, and tenderness over the anterior shin. There is no fluctuance, purulent drainage, or palpable fluid collection. Which of the following is the most appropriate antibiotic therapy?

A 34-year-old unhoused man is brought to the emergency department by paramedics after being found in severe distress in an alleyway. He sustained a deep puncture wound to his right sole from a rusty metal fence approximately 8 days ago. He has no known medical history, and his childhood vaccination status is unknown. On arrival, he is diaphoretic, tachycardic to 122/min, and tachypneic to 26/min. Physical examination reveals profound trismus, a sustained grimace of the facial muscles, and episodic, painful spasms of the paraspinal musculature that are immediately triggered by the noise of a dropping tray in the trauma bay. The right foot shows a 3-cm deep, purulent puncture wound surrounded by necrotic tissue.

Arrange the following therapeutic interventions in the most appropriate chronological sequence for the management of this patient's condition.