Internal Medicine

A 48-year-old man is hospitalized for severe acute pancreatitis. On admission, he was resuscitated with intravenous lactated Ringer solution and provided with adequate analgesia. On day 5 of his hospitalization, he reports persistent abdominal pain. His temperature is $38.3^\circ\text{C}$ ($100.9^\circ\text{F}$), blood pressure is $122/78\text{ mmHg}$, and pulse is $105/\text{min}$. Physical examination reveals epigastric tenderness without rebound. Laboratory studies show a leukocyte count of $15,200/\text{mm}^3$. A contrast-enhanced computed tomography scan of the abdomen demonstrates an enlarged pancreas with $>30\%$ non-enhancing necrotic tissue and surrounding peripancreatic fluid. No gas bubbles are visualized within the necrotic collections. Which of the following is the most appropriate next step in management?

A $72$-year-old man is evaluated in the intensive care unit for sudden, severe abdominal pain and bilious vomiting that began $4$ hours ago. He was admitted $2$ days ago for a chronic obstructive pulmonary disease (COPD) exacerbation. His past medical history is significant for COPD, heart failure with preserved ejection fraction, and a laparotomy for a perforated appendix $15$ years ago. Since the pain started, he has not passed flatus or stool. His temperature is $38.9^\circ\text{C}$ ($102.0^\circ\text{F}$), blood pressure is $82/50\text{ mmHg}$, pulse is $130/\text{min}$, and respiratory rate is $26/\text{min}$. The jugular venous pressure is $6\text{ cm H}_2\text{O}$. Physical examination reveals a markedly distended, rigid abdomen with diffuse tenderness, involuntary guarding, and rebound tenderness. Bowel sounds are absent. Laboratory studies show a leukocyte count of $23,000/\text{mm}^3$ and a serum lactate of $6.8\text{ mmol/L}$. Arterial blood gas analysis on room air reveals a pH of $7.28$, $\text{PaCO}_2$ of $30\text{ mmHg}$, and $\text{HCO}_3^-$ of $14\text{ mEq/L}$. An upright plain radiograph of the abdomen demonstrates multiple dilated loops of small bowel with air-fluid levels and no free intraperitoneal air. Which of the following is the most appropriate next step in management?

Match each clinical exposure scenario with the most appropriate post-exposure prophylaxis (PEP) regimen.

A $62$-year-old woman is brought to the emergency department by her family due to confusion, severe right upper quadrant abdominal pain, and subjective fevers over the past $24$ hours. Her temperature is $39.4^\circ\text{C}$ ($102.9^\circ\text{F}$), blood pressure is $88/54\text{ mmHg}$, heart rate is $118/\text{min}$, and respiratory rate is $22/\text{min}$. Physical examination reveals marked scleral icterus and severe tenderness to palpation in the right upper quadrant with guarding. She is disoriented to time and place. Laboratory studies are notable for a leukocyte count of $18,500/\mu\text{L}$, total bilirubin of $6.8\text{ mg/dL}$, alkaline phosphatase of $450\text{ U/L}$, and aspartate aminotransferase of $112\text{ U/L}$.

Arrange the following interventions in the most appropriate chronological sequence for the optimal management of this patient.

A 24-year-old woman with a history of type 1 diabetes mellitus presents to the emergency department with nausea, vomiting, and profound weakness for the past 24 hours. She has been unable to tolerate oral intake. Her blood pressure is 90/60 mm Hg, pulse is 122/min, and respirations are 28/min and deep. Laboratory studies show:

- Serum glucose: 580 mg/dL
- Arterial blood gas pH: 7.12
- Serum bicarbonate: 11 mEq/L
- Serum potassium: 3.1 mEq/L
- Serum sodium: 132 mEq/L
- Serum creatinine: 1.4 mg/dL

Arrange the following management steps in the most appropriate chronological order of execution.

Emergency medical services bring a 68-year-old woman to the emergency department after she collapsed in an airport terminal. She had just disembarked from a 12-hour international flight. On presentation, she is lethargic, diaphoretic, and in severe respiratory distress. Vital signs are temperature 36.8°C (98.2°F), blood pressure 76/44 mmHg, pulse 134/min, and respirations 32/min. Pulse oximetry shows 83% on room air. Physical examination reveals marked jugular venous distention when the head of the bed is elevated. The lungs are clear to auscultation bilaterally. Cardiac examination demonstrates a rapid, regular rhythm, a parasternal heave, and a loud pulmonic component of the second heart sound. The right lower extremity is edematous, warm, and tender from the calf to the mid-thigh. A bedside echocardiogram shows a dilated and hypokinetic right ventricle with bowing of the interventricular septum into the left ventricle. Arterial blood gas analysis on room air reveals a $pH$ of 7.22, $pCO_2$ of 28 mmHg, $pO_2$ of 54 mmHg, and $HCO_3^-$ of 11 mEq/L. Which of the following is the most appropriate next step in management?

During a routine follow-up appointment, a 38-year-old female reports a one-month history of progressive muscle weakness and fatigue. Her past medical history is significant for Sjögren syndrome and multiple episodes of calcium phosphate nephrolithiasis. Vital signs show a blood pressure of 118/76 mm Hg and a heart rate of 84/min. Physical examination reveals dry oral mucosa and 4/5 motor strength in the proximal muscles of the upper and lower extremities.

Laboratory evaluation reveals the following:

Based on these findings, what is this patient's calculated urine anion gap in mEq/L?

A $36$-year-old male software engineer visits the clinic complaining of a $3$-month history of constant sweating, a $5$-kg ($11$-lb) unintended weight loss, and frequent bowel movements. He also mentions a new onset of dull, constant headaches and occasionally bumping into doorframes on his sides over the past few weeks. His temperature is $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), blood pressure is $145/85 \text{ mmHg}$, and pulse is $105/\text{min}$. Physical examination reveals a mild resting tremor, moist skin, and a diffusely enlarged, non-tender thyroid gland without palpable nodules. Extraocular movements are intact, and there is no proptosis.

Laboratory studies are obtained and reveal the following:

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

A $76$-year-old woman is brought to the emergency department by her family due to severe, sudden-onset abdominal pain that started $3$ hours ago. She describes the pain as generalized, constant, and $10/10$ in intensity. She has had one episode of nonbilious emesis. Her medical history is significant for permanent atrial fibrillation, diet-controlled type 2 diabetes mellitus, and hypothyroidism. She admits to running out of her apixaban medication three weeks ago and has not taken it since. She takes levothyroxine daily.

Vital signs:
- Temperature: $37.4^\circ\text{C}$ ($99.3^\circ\text{F}$)
- Blood pressure: $105/65\text{ mm Hg}$
- Heart rate: $118/\text{min}$ and irregularly irregular
- Respiratory rate: $26/\text{min}$

Physical examination reveals a soft, non-distended abdomen. There is mild, diffuse tenderness to deep palpation, but no guarding, rigidity, or rebound tenderness. Bowel sounds are diminished.

Laboratory results:
- Leukocytes: $18,500/\text{mm}^3$
- Serum sodium: $138\text{ mEq/L}$
- Serum potassium: $4.2\text{ mEq/L}$
- Serum bicarbonate: $14\text{ mEq/L}$
- Blood urea nitrogen: $28\text{ mg/dL}$
- Serum creatinine: $1.2\text{ mg/dL}$
- Lactic acid: $5.8\text{ mmol/L}$ (normal: $0.5-2.2\text{ mmol/L}$)
- Thyroid-stimulating hormone (TSH): $0.1\text{ }\mu\text{U/mL}$ (normal: $0.4-4.0\text{ }\mu\text{U/mL}$)
- Free T4: $1.3\text{ ng/dL}$ (normal: $0.9-1.7\text{ ng/dL}$)

Arterial blood gas (room air):
- pH: $7.28$
- pCO2: $32\text{ mm Hg}$
- pO2: $88\text{ mm Hg}$

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

A 42-year-old man is evaluated in the hospital on day 3 of admission for community-acquired pneumonia. He initially presented with a productive cough, high fever, and shortness of breath. Chest radiography on admission showed a right lower lobe infiltrate. He was empirically started on intravenous ceftriaxone and azithromycin. Blood and sputum cultures obtained on admission have now grown Streptococcus pneumoniae. Susceptibility testing reveals the isolate is highly susceptible to penicillin (minimum inhibitory concentration < 0.06 mcg/mL), amoxicillin, ceftriaxone, and levofloxacin. Today, his temperature is 37.0 C (98.6 F), blood pressure is 120/78 mm Hg, pulse is 78/min, and respiratory rate is 14/min. His oxygen saturation is 97% on ambient air. He is tolerating a regular diet and reports feeling much better. Which of the following is the most appropriate next step in management?

A 65-year-old man with a history of chronic obstructive pulmonary disease (COPD) and ischemic cardiomyopathy (ejection fraction 40%) is evaluated in the intensive care unit. He was admitted 3 days ago for severe community-acquired pneumonia and was started on empiric intravenous vancomycin and cefepime. Today, his admission sputum cultures finalized, growing *Haemophilus influenzae* that is susceptible to ceftriaxone and ampicillin. Blood cultures remain negative.

Over the last 2 hours, the patient has developed increasing dyspnea, orthopnea, and severe anxiety.
Vital signs are temperature $37.1^\circ C$ ($98.8^\circ F$), blood pressure 165/95 mm Hg, heart rate 115/min, and respiratory rate 28/min.
Physical examination reveals elevated jugular venous pressure, an $S_3$ gallop, and coarse crackles up to the mid-lung fields bilaterally. Mild expiratory wheezes are also audible. There is 2+ pitting edema in both lower extremities.

Arterial blood gas analysis on a 4 L/min nasal cannula reveals:
pH: 7.29
$PaCO_2$: 30 mm Hg
$PaO_2$: 64 mm Hg
$HCO_3^-$: 14 mEq/L

Serum chemistry shows a lactate level of 4.0 mmol/L.

Which of the following are appropriate next steps in the management of this patient? (Select all that apply)

Paramedics transport a 69-year-old female to the acute care clinic due to a three-day history of escalating respiratory distress. The patient describes a persistent cough yielding frothy white sputum and states she has been sleeping in her recliner to avoid a choking sensation. She has a documented background of essential hypertension, hyperlipidemia, and a 45-pack-year smoking habit. She takes lisinopril and atorvastatin.

Upon initial triage, her core body temperature is 37.0°C (98.6°F), arterial blood pressure measures 168/96 mm Hg, heart rate is 115/min, and respiratory rate is 28/min. Oxygen saturation reads 86% while breathing ambient air.

Clinical assessment reveals elevated jugular venous pressure. Pulmonary auscultation identifies a markedly prolonged expiratory phase accompanied by diffuse, high-pitched wheezing throughout all lung fields; no localized crackles are evident. Cardiac auscultation reveals tachycardia with a distinct protodiastolic gallop (S3). Examination of the lower extremities shows bilateral pitting edema up to the mid-calf.

A bedside chest radiograph displays enlargement of the upper lobe pulmonary veins, indistinct vascular margins, and blunting of both costophrenic angles. No lobar opacities are present.

Which of the following is the most appropriate initial pharmacologic intervention for this patient?

A clinical investigator is reviewing the laboratory records of four distinct patients evaluated for abnormalities in bone and mineral metabolism. Match each patient's serum and urine laboratory profile to the most likely underlying pathophysiologic diagnosis.

A 68-year-old renal transplant recipient is brought to the emergency department by his family due to profound confusion and high fever for the past 24 hours. Vital signs show a temperature of 39.2°C (102.6°F), blood pressure of 110/70 mmHg, and heart rate of 115/min. Neurologic examination reveals marked nuchal rigidity, somnolence, and a new left-sided pronator drift. Arrange the following steps in the most appropriate sequential order for the initial management of this patient.

An $58$-year-old male with a history of poorly controlled hypertension is evaluated in the emergency department for severe, abrupt-onset chest pain radiating to his upper back. He describes the pain as "tearing" and rates it a $10$ out of $10$. He appears diaphoretic and in severe distress. Blood pressure is $215/115$ mm Hg in the right arm and $175/90$ mm Hg in the left arm. Heart rate is $115$/min. Neurologic examination is unremarkable. An electrocardiogram shows sinus tachycardia and voltage criteria for left ventricular hypertrophy. A portable chest radiograph reveals a widened mediastinum.

Arrange the following next steps in patient management in the optimal chronological sequence.

A $45$-year-old woman is evaluated in the clinic for an $8$-month history of worsening lethargy, unexplained weight gain, and generalized weakness. She also reports that her menstrual periods have been completely absent for the past year. Her blood pressure is $95/60$ mm Hg and her pulse is $55$/min. Physical examination reveals pale, dry skin and a noticeable delay in the relaxation phase of her deep tendon reflexes.

Laboratory studies reveal the following:

Based on these findings, which of the following is the most appropriate next step in management prior to initiating thyroid replacement therapy?

A 62-year-old man is brought to the emergency department by ambulance after experiencing sudden-onset, severe epigastric and lower chest pain for the past 90 minutes. He describes the pain as a "heavy weight" and reports associated nausea and profuse sweating. His medical history includes type 2 diabetes mellitus, peripheral arterial disease, and a 40-pack-year smoking history. Current medications include metformin and atorvastatin. On arrival, his temperature is 36.8 °C (98.2 °F), blood pressure is 82/50 mmHg, pulse is 112/min, and respiratory rate is 18/min. Pulse oximetry is 97% on room air. Physical examination reveals clear lungs to auscultation bilaterally. Jugular venous pulsations are visible 10 cm above the sternal angle while the patient is seated at a 45-degree angle. Cardiac auscultation reveals a regular rhythm without murmurs or gallops. The extremities are cool and clammy. An electrocardiogram reveals sinus tachycardia with 3-mm ST-segment elevations in leads II, III, and aVF, as well as 2-mm ST-segment depressions in leads I and aVL. The patient is administered chewable aspirin and ticagrelor. Which of the following is the most appropriate initial step to stabilize this patient's hemodynamics?

Match each patient's clinical presentation with the most likely corresponding arterial blood gas and basic metabolic panel profile.

A 65-year-old man with end-stage renal disease secondary to diabetic nephropathy is brought to the emergency department due to progressive generalized weakness and lethargy. He missed his last two scheduled hemodialysis sessions. His current heart rate is 54/min and blood pressure is 105/60 mm Hg. A stat basic metabolic panel is drawn, and the physician orders continuous cardiac monitoring. Assuming his serum potassium continues to rise untreated, arrange the following electrocardiographic (ECG) changes in the chronological order they are expected to appear.

Match each chronic liver disease to its classic serologic marker, genetic association, or histopathologic finding.