Internal Medicine

During a routine postnatal follow-up visit, a $31$-year-old female reports severe, persistent fatigue, feeling continuously cold, and experiencing dizziness upon standing. She delivered a healthy infant $5$ months ago via emergency cesarean delivery that was complicated by a severe hemorrhage requiring the transfusion of $4$ units of packed red blood cells. Since the delivery, she has been unable to produce breast milk and her menstrual cycles have not returned. Her blood pressure is $92/58$ mm Hg while seated and $80/50$ mm Hg upon standing. Pulse is $62$/min. Laboratory evaluation reveals the following:

Hemoglobin: $11.2$ g/dL
Sodium: $132$ mEq/L
Thyroid-stimulating hormone (TSH): $0.8$ $\mu$ U/mL (Normal: $0.4-4.0$ $\mu$ U/mL)
Free thyroxine (T4): $0.3$ ng/dL (Normal: $0.7-1.9$ ng/dL)

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

A 65-year-old man presents to the clinic with a 3-month history of progressive difficulty swallowing. Initially, he had trouble only with solid foods like meat and bread, but now he struggles to swallow liquids. He also reports a 9-kg (20-lb) unintentional weight loss over the same period. He has a 40-pack-year smoking history and consumes 2 to 3 alcoholic beverages daily. Physical examination is unremarkable. Routine laboratory tests show a new-onset microcytic anemia. Arrange the following diagnostic and management steps in the most appropriate chronological sequence for this patient.

A 68-year-old man with a history of severe chronic obstructive pulmonary disease (COPD) (FEV1 $35\%$ of predicted) and ischemic cardiomyopathy (left ventricular ejection fraction $30\%$) is brought to the emergency department due to severe shortness of breath that acutely worsened over the past 6 hours. He reports waking up from sleep gasping for air and has a cough productive of pink, frothy sputum. On arrival, his temperature is $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure is $178/102\text{ mmHg}$, pulse is $118\text{/min}$, and respiratory rate is $32\text{/min}$. Oxygen saturation is $84\%$ on room air. Physical examination reveals the use of accessory muscles of respiration, jugular venous distention to $12\text{ cm H}_2\text{O}$, and a third heart sound (S3). Lung auscultation reveals diffuse expiratory wheezing and bibasilar crackles. Arterial blood gas analysis on room air shows:

pH: $7.19$
PaCO2: $60\text{ mmHg}$
PaO2: $50\text{ mmHg}$
HCO3-: $22\text{ mEq/L}$

Which of the following are the most appropriate immediate interventions for this patient? (Select all that apply)

A 23-year-old woman with a history of asthma presents to the emergency department due to severe shortness of breath that began 6 hours ago. She has used her albuterol inhaler multiple times at home without relief. On physical examination, she appears highly anxious and is using accessory muscles to breathe. Her temperature is 37.0 °C (98.6 °F), blood pressure is 135/85 mmHg, pulse is 128/min, and respiratory rate is 32/min. Pulse oximetry shows an oxygen saturation of 90% on room air. Auscultation reveals markedly decreased breath sounds bilaterally with faint, diffuse expiratory wheezing.

An arterial blood gas analysis on room air demonstrates:
pH: 7.34
$PaCO_2$: 46 mm Hg
$PaO_2$: 58 mm Hg
$HCO_3^-$: 24 mEq/L

Which of the following is the most accurate interpretation of this patient's clinical presentation and laboratory findings?

A 68-year-old man is evaluated in the cardiac intensive care unit on day 4 of an admission for an anterior ST-segment elevation myocardial infarction. He initially presented 14 hours after symptom onset and underwent primary percutaneous coronary intervention of the left anterior descending artery. Over the past hour, he has developed severe dyspnea, agitation, and diaphoresis. His medical history includes hypertension, type 2 diabetes mellitus, and a 45-pack-year smoking history with known chronic obstructive pulmonary disease.

Vital signs:
Temperature: 37.2°C (99.0°F)
Blood pressure: 82/54 mm Hg
Pulse: 124/min
Respirations: 28/min
Oxygen saturation: 87% on room air

Physical examination reveals cool, clammy extremities with 1+ bilateral pitting edema. Jugular venous pressure is estimated at 12 cm $H_2O$. Lung auscultation reveals bilateral basilar crackles and diffuse expiratory wheezing. Cardiac auscultation reveals a regular tachycardia and a new, harsh, grade 4/6 holosystolic murmur with a palpable thrill at the left lower sternal border.

Arterial blood gas analysis on room air:
pH: 7.27
$PaO_2$: 55 mm Hg
$PaCO_2$: 32 mm Hg
$HCO_3^-$: 14 mEq/L

A pulmonary artery catheter is placed, yielding the following oxygen saturation ($S_vO_2$) data:

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

A 59-year-old male is brought to the emergency department by his spouse due to the sudden onset of crushing substernal chest pain that began 1 hour ago. He also reports profound weakness and diaphoresis. His medical history is significant for type 2 diabetes mellitus and hypertension. His current temperature is 37.1°C (98.8°F), blood pressure is 80/50 mmHg, heart rate is 110/min, and respiratory rate is 20/min. Pulse oximetry shows 95% on room air. On physical examination, the patient appears pale and diaphoretic. Jugular venous pulsation is visible 8 cm above the sternal angle. The lungs are clear to auscultation bilaterally with no wheezes or crackles. Cardiac auscultation reveals a regular tachycardia with no murmurs, rubs, or gallops. The extremities are cool and clammy with delayed capillary refill. Laboratory studies show a serum bicarbonate of 18 mEq/L and a lactate level of 4.5 mmol/L. An ECG reveals 3-mm ST-segment elevations in leads II, III, and aVF, as well as reciprocal ST-segment depressions in leads I and aVL. Which of the following is the most appropriate next step in the management of this patient's hemodynamic instability?

During a routine follow-up appointment, a $69$-year-old man is evaluated in the outpatient clinic for a $1$-month history of steadily increasing abdominal girth and swelling in both legs. He has a known history of severe chronic obstructive pulmonary disease (COPD) and is adherent to an inhaled corticosteroid, a long-acting beta-agonist, and a long-acting muscarinic antagonist. He quit smoking $3$ years ago after a $45$-pack-year history. The patient reports worsening exertional fatigue but explicitly denies waking up gasping for air at night or having trouble breathing when lying flat. Vital signs reveal a blood pressure of $126/80$ mm Hg, a heart rate of $92$/min, and a respiratory rate of $18$/min. Pulse oximetry shows an oxygen saturation of $87\%$ on room air. Physical examination demonstrates distended neck veins. Lung auscultation reveals globally decreased breath sounds and a prolonged expiratory phase, with no crackles appreciated. Cardiac examination shows a prominent parasternal impulse and a holosystolic murmur at the left lower sternal border that augments in intensity during inspiration. Abdominal exam is notable for a tender, palpable liver edge $4$ cm below the right costal margin. Bilateral $3+$ pitting edema is present up to the knees. Which of the following interventions is most likely to slow the progression of this patient's underlying cardiac condition and improve long-term survival?

A rapid response team is called to evaluate a 45-year-old woman on the general medical ward due to acute-onset lethargy. The patient was admitted 24 hours ago for a severe exacerbation of ulcerative colitis, presenting with numerous large-volume, watery bowel movements per day. Over the past 12 hours, she has received three doses of intravenous hydromorphone to manage severe abdominal cramping. On physical examination, her temperature is 37.1°C (98.8°F), blood pressure is 105/65 mmHg, pulse is 112/min, and respiratory rate is 8/min with shallow breathing. She is difficult to arouse but withdraws appropriately to painful stimuli.

Stat laboratory studies reveal the following:
Serum sodium: 135 mEq/L
Serum potassium: 3.1 mEq/L
Serum chloride: 115 mEq/L
Serum bicarbonate: 10 mEq/L
Blood urea nitrogen: 42 mg/dL
Serum creatinine: 1.8 mg/dL

Arterial blood gas analysis on room air shows:
pH: 7.10
PaO2: 68 mmHg
PaCO2: 36 mmHg

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

A $54$-year-old man with a history of hepatitis C virus infection and compensated cirrhosis is brought to the emergency department after vomiting bright red blood twice in the past hour. On presentation, his blood pressure is $88/56$ mm Hg, and his heart rate is $115$/min. He is lethargic but protecting his airway. Physical examination reveals scleral icterus, spider angiomata, and a distended abdomen with a positive fluid wave. Arrange the following interventions in the most appropriate chronological order for managing this patient's acute presentation.

Evaluate the following clinical presentations and pair each patient with the most likely predominant morphologic abnormality expected on their peripheral blood smear.

A $59$-year-old male is admitted to the hospital due to progressive fatigue, abdominal distension, and reduced urine output over the past five days. He has a history of cirrhosis secondary to nonalcoholic steatohepatitis. One week ago, his outpatient diuretic regimen of spironolactone and furosemide was increased to manage worsening ascites. Vital signs on admission show a temperature of $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure of $98/58\text{ mm Hg}$, and pulse of $88/\text{min}$. Physical examination reveals shifting dullness and trace bilateral pedal edema, but no signs of asterixis or hepatic encephalopathy.

Laboratory studies on admission reveal:
- Serum sodium: $131\text{ mEq/L}$
- Serum creatinine: $2.6\text{ mg/dL}$ (baseline $1.0\text{ mg/dL}$ one month ago)
- Blood urea nitrogen: $54\text{ mg/dL}$
- Urinalysis: normal, with a fractional excretion of sodium (FENa) less than $1\%$
- Ascitic fluid analysis: $150\text{ neutrophils/mm}^3$

All diuretics are immediately discontinued, and he is treated with an intravenous infusion of albumin ($1\text{ g/kg/day}$) for $48$ hours. Re-evaluation today shows a serum creatinine of $2.7\text{ mg/dL}$. Renal ultrasound shows normal-sized kidneys with no hydronephrosis. Which of the following is the most appropriate next step in management?

A 45-year-old man develops severe hypoxemia and bilateral pulmonary infiltrates 48 hours after being admitted for severe acute pancreatitis. He is diagnosed with acute respiratory distress syndrome (ARDS) and requires mechanical ventilation. The pathogenesis of this condition follows a well-described sequence of inflammatory and structural changes in the lungs. Arrange the following pathophysiological events of acute respiratory distress syndrome in the correct chronological order from the initial insult to the late stages.

Match each dynamic auscultation or hemodynamic finding to the most likely underlying cardiovascular pathology.

A 55-year-old standardized patient is being utilized for a bedside physical examination OSCE. Examinees are required to evaluate jugular venous pulse (JVP) waveforms. Match each detailed description of a JVP waveform abnormality with the cardiovascular pathology that best explains its pathogenesis.

Match each structural heart pathology with its most characteristic physical examination findings.

A $74$-year-old woman presents to the emergency department with severe, sudden-onset shortness of breath that began $2$ hours ago. She has a history of type 2 diabetes mellitus, essential hypertension, and a $40$-pack-year smoking history. Current medications include amlodipine, metformin, and atorvastatin. Her temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $185/105\text{ mmHg}$, pulse is $112\text{/min}$, and respirations are $28\text{/min}$. Pulse oximetry shows $88\%$ on room air. The patient appears anxious, diaphoretic, and is sitting upright. Physical examination reveals prominent jugular venous distention. Lung auscultation demonstrates diffuse expiratory wheezing bilaterally with crackles at the lung bases. Cardiac auscultation reveals a regular tachycardia with a prominent third heart sound ($S_3$). Lower extremities show trace pitting edema. Which of the following is the most appropriate next step in management?

A 68-year-old male arrives at the emergency department reporting a two-day history of progressively worsening shortness of breath. He also notes a significant increase in his baseline daily cough and reports that his sputum has changed from clear to thick and yellow-green. He has a 45-pack-year smoking history and was diagnosed with chronic obstructive pulmonary disease (COPD) three years ago. Vital signs show a temperature of 37.5°C (99.5°F), blood pressure of 140/90 mmHg, heart rate of 108/min, and respiratory rate of 24/min. Pulse oximetry demonstrates an oxygen saturation of 89% on room air. Physical examination reveals a barrel-shaped chest, use of accessory muscles of respiration, and a prolonged expiratory phase with diffuse bilateral wheezing. Jugular venous pressure is normal, and there is no peripheral edema. An arterial blood gas analysis on room air reveals the following:

In addition to supplemental oxygen, which of the following is the most appropriate initial combination of pharmacotherapy for this patient?

An unresponsive 52-year-old male is transported to the triage area by paramedics after being found in a mechanic's garage. According to bystanders, he had been drinking an unidentified liquid from a jug. His temperature is 36.5°C (97.7°F), blood pressure is 150/92 mm Hg, pulse is 108/min, and respirations are 24/min and deep. He responds only to painful stimuli.

Laboratory studies show the following:
Sodium: $139$ mEq/L
Potassium: $4.8$ mEq/L
Chloride: $104$ mEq/L
Bicarbonate: $10$ mEq/L
Blood urea nitrogen (BUN): $14$ mg/dL
Creatinine: $1.8$ mg/dL
Glucose: $90$ mg/dL
Measured serum osmolality: $318$ mOsm/kg $H_2O$

Arterial blood gas (room air):
pH: $7.22$
$PCO_2$: $23$ mm Hg
$PO_2$: $98$ mm Hg

Based on the provided laboratory data, what is the patient's serum osmolar gap?

Brought to the emergency department by his wife, a 41-year-old man has exhibited worsening fatigue, severe headache, and episodic confusion over the past four days. His wife mentions that his behavior has been highly uncharacteristic. His past medical history includes major depressive disorder, for which he was recently prescribed fluoxetine. His temperature is 38.1°C (100.6°F), blood pressure is 145/88 mm Hg, and pulse is 102/min. Physical examination reveals scattered petechiae over his bilateral lower extremities and mild scleral icterus. Neurologic examination shows no focal deficits, but the patient is disoriented to time and place. Cardiopulmonary examination is unremarkable.

Laboratory studies show:
Hemoglobin: 7.8 g/dL
Platelet count: 18,000/µL
Leukocyte count: 8,400/µL
Creatinine: 2.1 mg/dL
Total bilirubin: 3.8 mg/dL
Indirect bilirubin: 3.2 mg/dL
Lactate dehydrogenase: 1,100 U/L

A peripheral blood smear demonstrates numerous fragmented red blood cells. Which of the following is the most appropriate next step in management for this patient?

Match each of the following Hepatitis B serologic profiles with the most accurate clinical interpretation. Assume all patients have normal liver enzymes and no clinical signs of acute liver failure.