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Difficulty: MediumPediatric Cardiovascular Disorders

An 8-week-old girl is evaluated in the pediatric clinic for poor weight gain and respiratory difficulty. Her parents report that over the past three weeks, she has become increasingly irritable during feedings, sweats profusely, and frequently pauses to catch her breath. She has gained only 90 grams since her 1-month well-child visit. Her temperature is 37.0°C (98.6°F), heart rate is 166/min, respiratory rate is 65/min, and blood pressure is 85/50 mm Hg. Pulse oximetry shows 97% on room air. Physical examination reveals intercostal retractions and nasal flaring. Auscultation of the lungs demonstrates scattered bilateral wheezes and mild bibasilar crackles. Cardiac examination reveals a hyperdynamic precordium, a palpable thrill, and a harsh, 4/6 holosystolic murmur heard best at the left lower sternal border. The liver edge is palpated 3.5 cm below the right costal margin. Which of the following is the most appropriate next step in management?

  1. Administer intravenous furosemideAnswer
  2. B
    Administer inhaled albuterol
  3. C
    Administer intravenous ceftriaxone
  4. D
    Administer intravenous alprostadil
  5. E
    Provide reassurance and prescribe a high-calorie formula

Answer

Administer intravenous furosemide
Furosemide is a loop diuretic that rapidly decreases intravascular volume, which reduces pulmonary and hepatic congestion. This infant presents with classic signs of heart failure (diaphoresis during feeds, failure to thrive, tachypnea, hepatomegaly) secondary to a large left-to-right shunt from a ventricular septal defect (VSD), as indicated by the harsh holosystolic murmur and palpable thrill at the left lower sternal border. Diuretics are the initial pharmacologic treatment of choice to alleviate symptomatic volume overload in these patients.

Step-by-Step Solution

1
Analyze the clinical presentation and physical examination findings.
The infant exhibits failure to thrive, diaphoresis with feeds, tachypnea, hepatomegaly, and a harsh holosystolic murmur with a thrill at the left lower sternal border.
These are the classic signs of acute decompensated heart failure secondary to a large left-to-right shunt, specifically a Ventricular Septal Defect (VSD).
2
Identify the underlying pathophysiology causing the respiratory symptoms.
The left-to-right shunt causes pulmonary overcirculation, resulting in pulmonary edema (manifesting as crackles, wheezes, and retractions).
As pulmonary vascular resistance drops during the first few weeks of life, flow across the VSD increases, leading to symptomatic volume overload.
3
Determine the most appropriate initial medical intervention.
Administration of a diuretic, such as furosemide, is required.
Diuretics decrease intravascular volume and preload, which quickly alleviates the pulmonary congestion and improves respiratory mechanics.

Key Concept

Infants with large ventricular septal defects typically present at 4 to 8 weeks of age with heart failure (diaphoresis with feeding, poor weight gain, pulmonary edema) as pulmonary vascular resistance falls; initial management requires diuretics to reduce volume overload.
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Topics

Pediatric Cardiovascular Disorders

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