Internal Medicine

A 72-year-old woman is brought to the emergency department due to severe dizziness, confusion, and near-syncope. Her heart rate is 32/min, and blood pressure is 75/40 mm Hg. The 12-lead electrocardiogram reveals third-degree atrioventricular block. Arrange the following interventions in the optimal chronological sequence for managing this patient's symptomatic bradycardia, from initial emergency stabilization to definitive treatment.

A 72-year-old man is brought to the emergency department by emergency medical services due to severe, rapidly progressive shortness of breath that awoke him from sleep 2 hours ago. He has a history of ischemic cardiomyopathy with a left ventricular ejection fraction of 30%, chronic obstructive pulmonary disease (COPD), and chronic kidney disease. His home medications include lisinopril, metoprolol succinate, tiotropium, and as-needed albuterol. On arrival, he is in marked respiratory distress, speaking in short phrases and using accessory muscles of respiration. Vital signs are temperature $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure $178/96\text{ mmHg}$, heart rate $112/\text{min}$, respiratory rate $30/\text{min}$, and oxygen saturation 85% on room air. Physical examination reveals an elevated jugular venous pressure at 12 cm $H_2O$. Lung auscultation demonstrates diffuse expiratory wheezing and bilateral crackles extending to the mid-lung fields. Cardiac auscultation reveals a normal $S_1$ and $S_2$ with a prominent $S_3$ gallop. Bilateral 2+ pitting lower extremity edema is present.

Laboratory results:
Leukocyte count: $9,500/\text{mm}^3$
Thyroid-stimulating hormone (TSH): $1.1\ \mu\text{U/mL}$ (normal: $0.4-4.0\ \mu\text{U/mL}$)
Free thyroxine ($T_4$): $0.5\ \text{ng/dL}$ (normal: $0.9-1.7\ \text{ng/dL}$)

Arterial blood gas (room air):
pH: $7.22$
$PaCO_2$: $35\text{ mmHg}$
$PaO_2$: $55\text{ mmHg}$
$HCO_3^-$: $14\text{ mEq/L}$

Chest radiography reveals an enlarged cardiac silhouette, bilateral perihilar alveolar opacities, and prominent interlobular septal lines. Which of the following is the most appropriate initial step in the management of this patient?

A 57-year-old man visits his primary care provider due to a 3-day history of progressively worsening shortness of breath and a change in his chronic cough. He states that his usual mild morning cough is now occurring throughout the day and is producing thick, dark yellow sputum. He also feels unusually fatigued. His past medical history is significant for essential hypertension and a 35-pack-year history of smoking; he successfully quit smoking two years ago. His temperature is 37.9°C (100.2°F), blood pressure is 128/82 mm Hg, pulse is 96/min, and respiratory rate is 22/min. Oxygen saturation is 92% on room air. Physical examination reveals an augmented anteroposterior chest diameter and bilateral prolonged expiratory phases with diffuse wheezing. Evaluation of the neck shows flat jugular veins, and there is no trace of lower extremity edema. Cardiac auscultation reveals a regular rate and rhythm with no murmurs or gallops. In addition to inhaled bronchodilators and oral corticosteroids, which of the following is the most appropriate next step in pharmacologic management?

A primary care physician is evaluating a 68-year-old man who presents to an urgent care clinic with progressively worsening shortness of breath over the past 48 hours. The patient states he has been waking up in the middle of the night feeling as though he is suffocating and has required sleeping in a recliner chair. His past medical history is notable for essential hypertension, ischemic heart disease, and a 40-pack-year history of cigarette smoking. Current medications include daily aspirin, lisinopril, and atorvastatin. Vital signs show a temperature of 37.1 C (98.8 F), blood pressure of 158/92 mm Hg, heart rate of 108/min, and respiratory rate of 24/min. Oxygen saturation is 91% on ambient air. Physical examination reveals distended jugular veins when sitting upright. Cardiac auscultation demonstrates a regular tachycardia with a distinct third heart sound (S3). Lung auscultation yields bilateral crackles at the posterior lung bases without any audible wheezing. Palpation of the lower extremities reveals bilateral pitting edema extending to the knees. Which of the following is the most appropriate next step in the management of this patient?

During the physical examination of patients with suspected cardiovascular disease, assessing the arterial pulse can provide critical clues to the underlying hemodynamics and pathology. Match each of the following characteristic arterial pulse examination findings with the specific cardiovascular condition it most strongly indicates.

A 64-year-old man is brought to the emergency department by his family due to progressive confusion and severe shortness of breath. The family reports that he has had fever, chills, and a cough producing rust-colored sputum for the past 4 days. His medical history is significant for heart failure with preserved ejection fraction (HFpEF) and hypertension. His temperature is $39.1^\circ\text{C}$ ($102.4^\circ\text{F}$), pulse is $128\text{/min}$, respirations are $34\text{/min}$, and blood pressure is $82/48\text{ mm Hg}$. Pulse oximetry shows an oxygen saturation of $85\%$ on $15\text{ L/min}$ of oxygen via a non-rebreather mask. On physical examination, the patient is lethargic and arouses only to painful stimuli. He has marked suprasternal retractions and uses accessory muscles of respiration. Chest auscultation reveals dense crackles and egophony over the left lower lung field. The cardiovascular examination shows a rapid, regular rhythm with no jugular venous distention. Laboratory studies show a leukocyte count of $22,000/\mu\text{L}$ and a serum lactate of $7.2\text{ mmol/L}$. An arterial blood gas analysis on $15\text{ L/min}$ of supplemental oxygen reveals the following:

$pH$: $7.12$
$pCO_2$: $35\text{ mm Hg}$
$pO_2$: $54\text{ mm Hg}$
$HCO_3^-$: $11\text{ mEq/L}$

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

A 62-year-old man is evaluated for sudden-onset shortness of breath and right-sided pleuritic chest pain. He was admitted 6 days ago for an emergent exploratory laparotomy due to a small bowel obstruction. Following the surgery, he was started on subcutaneous unfractionated heparin for deep vein thrombosis prophylaxis.

On physical examination, his temperature is $37.8^\circ\text{C}$ ($100.0^\circ\text{F}$), heart rate is $118/\text{min}$, blood pressure is $122/78\text{ mmHg}$, respiratory rate is $24/\text{min}$, and oxygen saturation is $91\%$ on room air. The lungs are clear to auscultation bilaterally. The right calf is edematous, erythematous, and tender to palpation. The abdominal incision is clean and intact.

Laboratory results are as follows:

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

A 45-year-old man is evaluated in the intensive care unit 48 hours after being admitted for severe acute gallstone pancreatitis. Since admission, he has been receiving aggressive intravenous hydration with lactated Ringer solution and parenteral hydromorphone. He has been kept nothing by mouth. His temperature is 38.6°C (101.5°F), pulse is 118/min, blood pressure is 105/65 mmHg, and respirations are 26/min. Pulse oximetry shows 92% on room air. Physical examination reveals decreased breath sounds at both lung bases. The abdomen is distended, tympanic, and diffusely tender, most prominently in the epigastrium. Bowel sounds are absent. Laboratory studies show:

Leukocyte count: 18,500/mm³
Hemoglobin: 16.2 g/dL
Blood urea nitrogen: 32 mg/dL (was 18 mg/dL on admission)
Creatinine: 1.4 mg/dL
Calcium: 8.1 mg/dL

Arterial blood gas analysis on room air shows:
pH: 7.31
pCO₂: 29 mmHg
pO₂: 65 mmHg
HCO₃⁻: 14 mEq/L

A CT scan of the abdomen with intravenous contrast on admission showed 30% necrosis of the pancreatic body with no free air. A chest radiograph today demonstrates small bilateral pleural effusions. Which of the following is the most appropriate next step in the management of this patient?

An internal medicine physician is called to evaluate a $68$-year-old female patient in the observation unit who is reporting progressive shortness of breath and profound fatigue that has worsened over the past three weeks. The patient has a background of rheumatoid arthritis, currently managed with daily naproxen, as well as hypothyroidism. Upon assessment, she appears pale and lethargic. Vital signs indicate a heart rate of $112/\text{min}$, respiratory rate of $22/\text{min}$, blood pressure of $105/65\text{ mmHg}$, and a temperature of $37.6^\circ\text{C}$ ($99.7^\circ\text{F}$).

A physical examination reveals prominent conjunctival pallor and trace pitting edema in both ankles, but pulmonary auscultation is unremarkable with clear breath sounds bilaterally.

Laboratory analysis is immediately obtained and returns the following results:

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

A 59-year-old male with chronic hepatitis C virus-induced cirrhosis is brought to the acute care clinic by his daughter due to an acute decline in his cognitive baseline over the last two days. The daughter reports that he has been sleeping extensively during the day and is increasingly disoriented. He has a history of ascites managed with spironolactone and furosemide. He has not had any hospitalizations or healthcare exposures in the past year.

On physical examination, temperature is 37.4°C (99.3°F), blood pressure is 105/65 mm Hg, and pulse is 92/min. The patient is lethargic and oriented only to person. Scleral icterus is present. The abdomen is tensely distended with a positive fluid wave and mild, diffuse tenderness to deep palpation. Rebound tenderness and guarding are absent. Asterixis is elicited upon wrist extension.

Laboratory studies reveal the following:

A diagnostic paracentesis yields cloudy fluid with a total protein of 0.8 g/dL and a leukocyte count of 650/mm³. The differential shows 60% neutrophils and 40% lymphocytes. Gram stain of the fluid is negative.

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

A 35-year-old woman presents to the clinic with a 3-day history of watery diarrhea, mild abdominal cramping, and nausea. She reports 4 to 5 loose bowel movements daily but denies fever, bloody stools, recent travel, or sick contacts. Her only medication is a daily oral contraceptive pill. Temperature is 37.0°C (98.6°F), blood pressure is 118/76 mmHg, and pulse is 82/min. The abdomen is soft and non-distended, with mild diffuse tenderness but no guarding or rebound. Bowel sounds are hyperactive. Which of the following is the most appropriate next step in management?

A 58-year-old male receives a hepatology consultation due to an insidious onset of dyspnea that has worsened over the past four months. His past medical history is significant for cryptogenic cirrhosis. The patient notes a peculiar pattern to his symptoms: his shortness of breath is most severe when he is standing upright and improves significantly shortly after he lies flat in bed. Physical examination is notable for palmar erythema, multiple spider angiomas on the upper chest, and pronounced digital clubbing. Lung fields are clear to auscultation bilaterally, and no cardiac murmurs are appreciated.

Arterial blood gas analysis obtained while the patient is standing on room air reveals:

Additional laboratory studies show:

Echocardiography with agitated saline contrast demonstrates the appearance of microbubbles in the left atrium five cardiac cycles after their initial visualization in the right atrium. Left ventricular ejection fraction is 65%.

Which of the following is the most appropriate definitive management for this patient's current condition?

Match each clinical presentation of an acid-base disturbance to its most corresponding arterial blood gas (ABG) profile. Assume normal reference ranges for ABG are pH $7.35-7.45$, $PaCO_2$ $35-45$ mm Hg, and $HCO_3^-$ $22-26$ mEq/L.

A $62$-year-old man is evaluated in the intensive care unit for worsening hypoxemia. He underwent an exploratory laparotomy for a perforated appendix $48$ hours ago. He was started on targeted antimicrobial therapy with piperacillin-tazobactam after peritoneal fluid cultures grew pan-sensitive *Escherichia coli* and *Bacteroides fragilis*. The patient is sedated and mechanically ventilated in assist-control volume mode. Current settings include a tidal volume of $400$ mL ($6$ mL/kg of predicted body weight), respiratory rate of $28$/min, positive end-expiratory pressure (PEEP) of $14$ cm H $_2$ O, and fraction of inspired oxygen (FiO $_2$) of $0.80$.

Vital signs show a temperature of $38.2^\circ$ C ($100.8^\circ$ F), pulse of $110$/min, and blood pressure of $105/60$ mmHg while receiving a continuous norepinephrine infusion at $0.1$ $\mu$ g/kg/min. Arterial blood gas analysis reveals:
pH: $7.18$
PaCO $_2$: $55$ mmHg
PaO $_2$: $58$ mmHg
HCO $_3^-$: $20$ mEq/L

Ventilator mechanics demonstrate a peak airway pressure of $40$ cm H $_2$ O and a plateau airway pressure of $36$ cm H $_2$ O. A bedside chest radiograph shows diffuse bilateral alveolar opacities.

Which of the following are the most appropriate next steps in the management of this patient? (Select exactly 2 options)

A 52-year-old woman is hospitalized for induction chemotherapy for acute myeloid leukemia. On hospital day 12, she develops a new-onset fever of $38.7^\circ\text{C}$ ($101.7^\circ\text{F}$). Her blood pressure is 118/74 mm Hg, pulse is 98/min, and respirations are 16/min. Physical examination reveals no focal source of infection, and the exit site of her right internal jugular central venous catheter is clean without erythema or induration. Laboratory studies show an absolute neutrophil count of $150/\text{mm}^3$. She is hemodynamically stable and appears fatigued.

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

A 65-year-old woman is evaluated in the intensive care unit for abnormal laboratory findings. She was admitted 4 days ago with severe community-acquired pneumonia complicated by septic shock. She was initially treated with broad-spectrum intravenous antibiotics and vasopressors, and her clinical condition has been steadily improving over the last 24 hours. She is currently extubated and her vasopressors were discontinued yesterday. Her temperature is $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), blood pressure is $112/70\text{ mm Hg}$, and pulse is $84\text{/min}$. Physical examination reveals resolving crackles in the right lower lung base. There is no thyromegaly or delayed relaxation of deep tendon reflexes. A thyroid panel was drawn by the covering clinical team to evaluate her fatigue. Results are as follows:

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

A 45-year-old man is evaluated for resistant hypertension and persistent muscle cramps. His blood pressure is $168/102$ mm Hg despite strict adherence to a three-drug antihypertensive regimen that includes a thiazide diuretic. Laboratory testing reveals a serum potassium of $2.9$ mEq/L and a normal serum sodium. The physician suspects an endocrine etiology for his secondary hypertension. Arrange the following diagnostic and therapeutic steps in the correct chronological sequence for establishing the diagnosis and managing this patient's condition.

A $48$-year-old woman comes to the emergency department due to a severe, throbbing headache, blurred vision, and worsening shortness of breath for the past $2$ days. She has a $3$-year history of diffuse cutaneous systemic sclerosis. Her current medications include mycophenolate mofetil and omeprazole. Her blood pressure is $220/120$ mm Hg, pulse is $98$/min, and respirations are $22$/min. Physical examination shows thickened, tight skin over the face, trunk, and upper extremities. Cardiopulmonary examination reveals bilateral basilar lung crackles. Laboratory studies show:

Hemoglobin: $9.2$ g/dL
Platelets: $95,000$/mm $^3$
Creatinine: $2.8$ mg/dL (baseline $0.9$ mg/dL)

Peripheral blood smear demonstrates multiple schistocytes. Which of the following is the most appropriate initial treatment for this patient's acute kidney injury and hypertension?

Match each patient's clinical presentation with the most appropriate specific diagnostic evaluation or characteristic finding used to establish the diagnosis.

Review the following distinct laboratory profiles regarding calcium and phosphorus metabolism. Match each patient's serum and urine laboratory findings to the most accurate underlying pathophysiologic mechanism.