Internal Medicine

A 58-year-old man with advanced cirrhosis due to nonalcoholic steatohepatitis is evaluated in the hospital on day 3 of his admission. He originally presented from a skilled nursing facility with fever, worsening ascites, and hepatic encephalopathy. On admission, diagnostic paracentesis revealed cloudy fluid with an absolute neutrophil count of 850/mm³. Due to his recent healthcare exposure and a history of urinary tract infections caused by extended-spectrum beta-lactamase (ESBL)-producing organisms, he was empirically started on intravenous meropenem and received appropriate albumin infusions.

Today, the patient is afebrile, alert, and fully oriented. His abdominal pain has resolved. Blood and ascitic fluid cultures obtained on admission have grown *Escherichia coli*. Antimicrobial susceptibility testing demonstrates that the isolate is resistant to ampicillin but susceptible to ceftriaxone, ciprofloxacin, trimethoprim-sulfamethoxazole, and meropenem.

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

During multidisciplinary rounds in the medical intensive care unit, the team evaluates a patient who repeatedly fails spontaneous breathing trials. The patient, a $69$-year-old woman with a history of severe chronic obstructive pulmonary disease (COPD) and ischemic cardiomyopathy (ejection fraction $25\%$), was admitted $5$ days ago for acute hypercapnic respiratory failure and cardiogenic pulmonary edema.

On admission, she was intubated and placed on mechanical ventilation. She has since received treatment with inhaled bronchodilators, systemic glucocorticoids, and continuous intravenous furosemide, resulting in a net fluid loss of $6.5$ L and complete resolution of pulmonary crackles.

Today, her sedation is paused, and she is alert and following commands. A spontaneous breathing trial is initiated with continuous positive airway pressure (CPAP) of $5$ cm $H_2O$. However, within $10$ minutes, her respiratory rate drops to $6$/min with shallow tidal volumes, triggering an apnea alarm, and she is placed back on full ventilatory support.

Vital signs are temperature $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure $112/68$ mm Hg, and heart rate $84$/min. Jugular venous pressure is $7$ cm $H_2O$.

Arterial blood gas (on assist-control ventilation, rate $12$/min, tidal volume $400$ mL, $FiO_2$ $0.30$):
pH: $7.54$
$PaCO_2$: $53$ mm Hg
$PaO_2$: $82$ mm Hg
$HCO_3^-$: $44$ mEq/L

Which of the following is the most appropriate next step in management to facilitate weaning from mechanical ventilation?

A $67$-year-old man presents to the primary care clinic reporting progressively worsening fatigue and dyspnea on exertion over the past $3$ months. He denies any chest pain, orthopnea, or recent cough. He has a past medical history of hypertension and hyperlipidemia. His medications include lisinopril and atorvastatin. Vital signs show a blood pressure of $135/82$ mmHg, pulse of $92$/min, and respiratory rate of $16$/min. Physical examination reveals pale conjunctivae but no jaundice, cyanosis, or peripheral edema. Cardiopulmonary examination is unremarkable. Digital rectal examination reveals brown stool; no palpable masses are present.

Laboratory studies:
Hemoglobin: $8.4$ g/dL
Hematocrit: $26\%$
Mean corpuscular volume: $72$ fL
Leukocyte count: $6,500$/mm $^3$
Platelet count: $410,000$/mm $^3$

Serum iron: $30$ $\mu$ g/dL
Total iron-binding capacity (TIBC): $450$ $\mu$ g/dL
Serum ferritin: $12$ ng/mL

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

Evaluate the following clinical scenarios describing patients with varied presentations of renal dysfunction. Correlate each patient's presentation with the most characteristic predominant finding expected on their urine microscopy.

A 42-year-old man comes to the clinic for evaluation of sudden, severe headaches associated with profuse sweating and heart palpitations. These episodes occur 2 to 3 times a week, typically lasting for 15 to 20 minutes. He has no significant past medical history and takes no medications. His blood pressure during the visit is 172/105 mm Hg, and his pulse is 105/min. The rest of his physical examination is unremarkable. Arrange the following steps in the most appropriate chronological order for the evaluation and management of this patient's suspected condition.

A 68-year-old woman is brought to the emergency department from a skilled nursing facility due to altered mental status, fever, and right upper quadrant abdominal pain for the past 24 hours. Her temperature is 39.2°C (102.6°F), blood pressure is 86/52 mm Hg, pulse is 118/min, and respirations are 22/min. Physical examination demonstrates scleral icterus, dry mucous membranes, and significant tenderness to palpation in the right upper quadrant with involuntary guarding. Laboratory studies reveal a leukocyte count of 18,500/mm³, total bilirubin of 5.8 mg/dL, direct bilirubin of 4.2 mg/dL, and alkaline phosphatase of 450 U/L.

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

A $54$-year-old man is admitted to the hospital with a $5$-day history of fever, productive cough, and right-sided pleuritic chest pain. His temperature is $39.0^\circ\text{C}$ ($102.2^\circ\text{F}$), pulse is $112/\text{min}$, and respiratory rate is $24/\text{min}$. A portable chest radiograph demonstrates a right lower lobe consolidation and a moderate, free-flowing right-sided pleural effusion. He is initiated on empiric intravenous ceftriaxone and azithromycin. Over the next $48$ hours, he remains persistently febrile and tachycardic, and his oxygen requirement increases.

Assume that the patient's clinical condition requires sequential escalation of interventions due to the failure of each preceding step. Arrange the following management steps in the most appropriate chronological order according to standard treatment guidelines.

A $72$-year-old female with a medical history of severe chronic obstructive pulmonary disease and heart failure with reduced ejection fraction ($35\%$) is evaluated in the intensive care unit for worsening hemodynamic instability. She was admitted to the hospital three days ago with a left lower lobe community-acquired pneumonia. Following progressive hypoxemia and increased work of breathing, she was intubated yesterday. She is currently sedated and paralyzed.

Over the past $4$ hours, her blood pressure has steadily declined despite receiving $30$ mL/kg of lactated Ringer solution.

Vital signs:
* Temperature: $38.9^\circ \text{C}$ ($102.0^\circ \text{F}$)
* Heart rate: $118$/min
* Blood pressure: $76/40$ mmHg
* $\text{SpO}_2$: $92\%$

Physical examination reveals a mottled appearance of the lower extremities. Jugular venous pressure is $8$ cm $\text{H}_2\text{O}$. Auscultation demonstrates left basilar crackles and bilateral expiratory wheezing. Bedside echocardiography shows an ejection fraction of $35\%$ without right ventricular enlargement or pericardial effusion.

Sputum cultures obtained on admission are now growing *Streptococcus pneumoniae* susceptible to ceftriaxone, levofloxacin, and vancomycin. The patient is currently receiving empiric therapy with intravenous vancomycin, cefepime, and azithromycin.

Ventilator settings (Volume Control):
* Tidal volume: $380$ mL ($6$ mL/kg predicted body weight)
* Respiratory rate: $12$/min
* $\text{FiO}_2$: $0.60$
* PEEP: $12$ cm $\text{H}_2\text{O}$

Arterial blood gas (drawn $15$ minutes ago):
* pH: $7.18$
* $\text{PaCO}_2$: $44$ mmHg
* $\text{PaO}_2$: $65$ mmHg
* $\text{HCO}_3^-$: $16$ mEq/L

Which of the following are the most appropriate immediate steps in management? (Select all that apply)

A 32-year-old man is brought to the emergency department by paramedics after being found unresponsive in his apartment. Bystanders report that he may have used heroin and had been lying in the same position for an unknown duration. On arrival, his temperature is 36.8°C (98.2°F), blood pressure is 105/65 mm Hg, pulse is 88/min, and respiratory rate is 10/min. Physical examination reveals pinpoint pupils and marked swelling and induration of the right lower extremity.

Laboratory studies show the following:

Arterial blood gas analysis on room air reveals:

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

Match each patient's clinical presentation with the most likely predominant finding on a peripheral blood smear.

During a winter clinic visit, a 34-year-old female with known limited cutaneous systemic sclerosis reports increasingly painful episodes where her fingers turn stark white, then blue, when exposed to the cold. Physical examination reveals taut skin over the digits but no active ulceration. She is currently not taking any medications for this specific symptom. Arrange the following management steps in the standard escalating sequence for this condition, starting from initial baseline interventions and progressing to therapies reserved for severe, refractory digital ischemia.

A 42-year-old man presents to a gastroenterology clinic with a 1-year history of severe, burning epigastric pain and chronic high-volume watery diarrhea. The abdominal pain frequently awakens him at night and is only minimally relieved by high-dose pantoprazole, which he has taken reliably for the past 6 months. He has no personal or family history of nephrolithiasis, hypercalcemia, or pituitary disease. An upper endoscopy performed prior to referral revealed remarkably prominent gastric folds and multiple deep ulcerations in the duodenal bulb and the descending duodenum. The physician highly suspects Zollinger-Ellison syndrome (ZES) and plans to initiate a comprehensive diagnostic and management algorithm.

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

A 29-year-old woman is brought to the emergency department by her husband due to progressive lethargy and profound weakness. For the past 4 days, she has had severe, voluminous watery diarrhea and poor oral intake following a sick contact. Her medical history is significant for idiopathic intracranial hypertension, for which she takes acetazolamide. Her temperature is 37.2°C (99.0°F), blood pressure is 98/60 mmHg, pulse is 112/min, and respiratory rate is 16/min. Physical examination shows dry mucous membranes, decreased skin turgor, and generalized diminished muscle strength in all extremities.

Laboratory studies show the following:
Serum sodium: 136 mEq/L
Serum potassium: 2.2 mEq/L
Serum chloride: 116 mEq/L
Serum bicarbonate: 10 mEq/L
Blood urea nitrogen: 42 mg/dL
Serum creatinine: 1.6 mg/dL

Arterial blood gas (room air):
pH: 7.11
$pCO_2$: 32 mmHg
$pO_2$: 88 mmHg

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

A 68-year-old man is admitted to the hospital with acute decompensated heart failure. He is started on an intravenous bumetanide infusion. On hospital day 3, his urine output decreases to 300 mL over the last 24 hours. Physical examination shows jugular venous distention, bibasilar crackles, and bilateral lower extremity pitting edema.

Laboratory studies are obtained:
Serum sodium: $140 \text{ mEq/L}$
Serum potassium: $3.5 \text{ mEq/L}$
Serum chloride: $98 \text{ mEq/L}$
Serum bicarbonate: $26 \text{ mEq/L}$
Serum blood urea nitrogen (BUN): $60 \text{ mg/dL}$
Serum creatinine: $2.0 \text{ mg/dL}$

A spot urine sample is analyzed:
Urine sodium: $105 \text{ mEq/L}$
Urine blood urea nitrogen (BUN): $600 \text{ mg/dL}$
Urine creatinine: $100 \text{ mg/dL}$

Based on these findings, what is the patient's fractional excretion of urea nitrogen (expressed as a percentage)?

A $52$-year-old man comes to the physician due to progressive fatigue, unintentional weight loss, and a feeling of early satiety over the past $3$ months. He has no other medical conditions and takes no medications. His temperature is $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), blood pressure is $128/78\text{ mmHg}$, and pulse is $82/\text{min}$. Physical examination reveals a palpable spleen edge $8\text{ cm}$ below the left costal margin. There is no palpable cervical, axillary, or inguinal lymphadenopathy. Laboratory studies show the following:

A peripheral blood smear demonstrates a full spectrum of granulocytic cells, including $5\%$ myeloblasts, $10\%$ promyelocytes, $15\%$ myelocytes, $10\%$ metamyelocytes, $15\%$ bands, $35\%$ neutrophils, $6\%$ eosinophils, and $4\%$ basophils. The leukocyte alkaline phosphatase score is markedly decreased. Which of the following is the most appropriate next step in the evaluation or management of this patient?

A 42-year-old man with a history of poorly controlled HIV infection presents to the emergency department with a 2-day history of worsening headache, severe photophobia, and confusion. On presentation, his temperature is 39.4°C (102.9°F), blood pressure is 115/75 mm Hg, pulse is 118/min, and respirations are 18/min. Physical examination reveals marked nuchal rigidity. He is oriented only to his name. Funduscopic examination shows blurring of the optic disc margins bilaterally.

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

A 68-year-old man is evaluated in the hospital on the third day of admission for acute ascending cholangitis. He initially presented with a 2-day history of right upper quadrant abdominal pain, fever, and jaundice. On admission, his temperature was 39.2°C (102.6°F) and blood pressure was 98/60 mm Hg. Laboratory studies showed a leukocyte count of 16,500/mm³, total bilirubin of 4.2 mg/dL, and alkaline phosphatase of 450 U/L.

He was empirically started on intravenous piperacillin-tazobactam and received aggressive fluid resuscitation. Within 12 hours of admission, he underwent urgent endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy and extraction of a common bile duct stone.

Today, the patient feels much better. His temperature is 37.1°C (98.8°F), blood pressure is 122/78 mm Hg, and pulse is 78/min. His abdominal examination shows mild right upper quadrant tenderness without rebound or guarding.

Blood cultures drawn on admission are now growing *Escherichia coli*. The susceptibility report is as follows:

Based on these results, which of the following is the most appropriate next step in the management of this patient's antibiotic therapy?

A 26-year-old female medical student presents to the student health clinic reporting a two-day history of frequent, watery bowel movements. She notes having four to five loose stools daily, accompanied by mild, diffuse abdominal cramping. She has not noticed any visible blood or mucus in the toilet. The patient denies any recent international travel, new medications, or known exposure to sick individuals. Her only regular medication is a daily oral contraceptive. Her temperature is 37.1°C (98.8°F), blood pressure is 116/74 mm Hg, and pulse is 80/min. Abdominal examination reveals a soft, non-distended abdomen with hyperactive bowel sounds. There is mild, generalized tenderness to deep palpation, but no guarding, rigidity, or rebound tenderness.

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

A 28-year-old woman is brought to the emergency department by her family due to severe agitation, confusion, and palpitations that have progressively worsened over the past 24 hours. She has a history of Graves disease but stopped taking her medications three months ago. On physical examination, her temperature is 39.8°C (103.6°F), blood pressure is 160/90 mm Hg, heart rate is 148/min and irregular, and respiratory rate is 24/min. She is delirious, diaphoretic, and has a noticeable fine tremor. Neck examination reveals a diffusely enlarged, non-tender thyroid gland with a bruit. ECG shows atrial fibrillation with rapid ventricular response. Laboratory studies confirm a TSH level of < 0.01 µU/mL and a free T4 of 5.8 ng/dL. Arrange the following interventions in the most appropriate chronological order for the comprehensive management of this patient, from initial acute stabilization to long-term definitive care.

A 52-year-old woman presents to the emergency department with severe, sudden-onset epigastric pain radiating to her back, accompanied by intractable nausea. Her heart rate is 112/min and blood pressure is 105/65 mm Hg. Laboratory studies reveal a serum lipase level of 1,250 U/L and an alanine aminotransferase (ALT) level of 185 U/L. She is diagnosed with acute gallstone pancreatitis. Assuming her clinical course is complicated by new-onset fever and worsening jaundice on hospital day 2, arrange the following interventions in the most appropriate chronological sequence for her overall management.