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Difficulty: MediumCardiovascular System

A 6666-year-old man is evaluated in the emergency department for sudden, severe difficulty breathing that awoke him from sleep. The patient states he felt as though he were suffocating and developed a cough producing frothy sputum. His past medical history is notable for a 4545-pack-year smoking habit and an anterior ST-segment elevation myocardial infarction three years prior, for which he underwent percutaneous coronary intervention. His daily medications include low-dose aspirin, carvedilol, and rosuvastatin, but he admits to running out of these medications two weeks ago.

Vital signs reveal a temperature of 37.0∘C37.0^\circ\text{C} (98.6∘F98.6^\circ\text{F}), blood pressure of 172/96 mmHg172/96\text{ mmHg}, heart rate of 112/min112/\text{min}, and respiratory rate of 26/min26/\text{min}. Pulse oximetry shows an oxygen saturation of 87%87\% on room air.

On physical examination, the patient is in severe respiratory distress and utilizing accessory muscles. Jugular venous distention is prominent up to the angle of the mandible while the patient is sitting upright. Pulmonary auscultation demonstrates prolonged expiratory phases with loud, diffuse wheezing in all lung fields, alongside bilateral crackles at the lung bases. Cardiac auscultation reveals a regular, rapid rhythm with a distinct low-frequency diastolic sound heard just after S2. There is 2+2+ pitting edema extending to the mid-calves bilaterally.

An arterial blood gas analysis on room air shows:
pH: 7.287.28
PaCO 2_2: 56 mmHg56\text{ mmHg}
PaO 2_2: 58 mmHg58\text{ mmHg}
HCO 3−_3^-: 25 mEq/L25\text{ mEq/L}

Which of the following is the most appropriate initial pharmacologic step in managing this patient's condition?

  1. Administer intravenous torsemideAnswer
  2. B
    Administer nebulized levalbuterol
  3. C
    Administer intravenous methylprednisolone
  4. D
    Administer intravenous sodium bicarbonate
  5. E
    Administer oral azithromycin

Answer

Administer intravenous torsemide
This patient's presentation of severe sudden-onset dyspnea, orthopnea, profound hypoxemia, jugular venous distention, an S3 gallop, and bilateral pitting edema is highly indicative of acute decompensated heart failure (ADHF) leading to cardiogenic pulmonary edema. His recent medication nonadherence (specifically missing his beta-blocker) likely precipitated this event. The presence of diffuse wheezing in this context is known as 'cardiac asthma,' which occurs due to peribronchial edema compressing the small airways, rather than primary bronchospasm. The most appropriate initial pharmacologic management is an intravenous loop diuretic (e.g., torsemide, furosemide), which decreases intravascular volume, reduces ventricular preload, and rapidly alleviates pulmonary congestion.

Step-by-Step Solution

1
Identify the primary clinical syndrome based on the patient's history and physical examination findings.
The patient exhibits signs of severe volume overload (jugular venous distention, S3 gallop, peripheral edema) and pulmonary congestion (crackles, frothy sputum, severe hypoxemia) strongly indicating acute decompensated heart failure (ADHF).
A history of prior myocardial infarction and medication nonadherence are classic triggers for ADHF. The wheezing represents 'cardiac asthma' resulting from peribronchial edema compressing the airways, rather than primary bronchospasm from COPD.
2
Interpret the arterial blood gas (ABG) results to evaluate respiratory status.
The ABG demonstrates a pH of 7.28, PaCO2 of 56 mmHg, and a normal HCO3- of 25 mEq/L, which indicates an uncompensated acute respiratory acidosis.
Severe pulmonary edema impairs gas exchange and dramatically increases the work of breathing, leading to alveolar hypoventilation and acute CO2 retention.
3
Determine the most appropriate initial pharmacologic intervention for the identified condition.
An intravenous loop diuretic (such as torsemide or furosemide) should be administered immediately.
Loop diuretics rapidly reduce ventricular preload through venodilation and subsequent diuresis, which is the definitive initial management for cardiogenic pulmonary edema.

Key Concept

Differentiating acute decompensated heart failure presenting with 'cardiac asthma' from a primary COPD exacerbation, and initiating appropriate preload-reducing therapy.
Estimated Time:1m 30s
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Topics

Cardiovascular System

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