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Difficulty: HardNeonatal Disorders

An infant boy is evaluated in the neonatal intensive care unit for increased work of breathing. He was born 4 hours ago to a 30-year-old gravida 2, para 2 woman at 38 weeks gestation. Delivery was via elective repeat cesarean section prior to the onset of labor. The mother has a history of diet-controlled gestational diabetes. Her prenatal screening for group B *Streptococcus* was negative.

Upon evaluation, the infant appears tachypneic. Vital signs are temperature 36.9°C (98.4°F), heart rate 155/min, respiratory rate 82/min, and blood pressure 60/40 mm Hg. Oxygen saturation is 89% on room air. Physical examination reveals nasal flaring, subcostal retractions, and a clear chest to auscultation. The skin examination shows multiple 1- to 2-mm firm, pale yellow pustules surrounded by erythematous halos distributed across the trunk and proximal extremities.

Arterial blood gas on room air shows:

ParameterValueReference Range
pHpH7.247.35 - 7.45
PaCO2PaCO_262 mm Hg35 - 45 mm Hg
HCO3−HCO_3^-26 mEq/L22 - 28 mEq/L

A chest radiograph demonstrates prominent perihilar vascular markings, hyperinflation, and a thin line of radiodensity in the right horizontal fissure.

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

  1. Initiate continuous positive airway pressure and provide supportive careAnswer
  2. B
    Administer nebulized albuterol and systemic corticosteroids
  3. C
    Obtain blood cultures and initiate broad-spectrum intravenous antibiotics
  4. D
    Administer an intravenous infusion of sodium bicarbonate
  5. E
    Perform a skin swab for herpes simplex virus and initiate intravenous acyclovir

Answer

The correct answer is to initiate continuous positive airway pressure and provide supportive care.
The correct response represents the standard supportive management for transient tachypnea of the newborn (TTN). This infant's presentation of tachypnea, retractions, and hypoxia shortly after an elective cesarean delivery without labor is classic for TTN, which is caused by delayed clearance of fetal lung fluid. The chest radiograph confirms the diagnosis by demonstrating fluid in the horizontal fissure and perihilar streaking. The acid-base status indicates a primary uncompensated respiratory acidosis, an expected finding due to poor ventilation from fluid-filled alveoli. Furthermore, the skin findings describe erythema toxicum neonatorum, a completely benign and self-limited rash that requires no intervention. The appropriate management for TTN is supportive care with supplemental oxygen or continuous positive airway pressure (CPAP) to help stent open the airways and drive fluid out of the alveoli.

Step-by-Step Solution

1
Analyze the patient's risk factors and respiratory presentation.
The infant is a term newborn delivered via elective cesarean section without prior labor, presenting with early-onset tachypnea, retractions, and hypoxia.
Delivery without labor prevents the normal catecholamine-induced physiologic clearance of fetal lung fluid, strongly predisposing the infant to transient tachypnea of the newborn (TTN).
2
Interpret the radiographic and laboratory findings.
The chest radiograph shows fluid in the fissures and perihilar streaking. The arterial blood gas shows an acute respiratory acidosis (pHpH 7.24, high PaCO2PaCO_2, normal HCO3−HCO_3^-).
These findings definitively support TTN caused by retained lung fluid impairing ventilation, rather than a metabolic derangement or primary lung consolidation.
3
Evaluate the cutaneous findings.
The rash consisting of yellow-white pustules on an erythematous base in an otherwise vigorous newborn is identified as erythema toxicum neonatorum (ETN).
ETN is a common, benign, self-limiting condition that must be distinguished from severe systemic infections like neonatal herpes simplex virus or staphylococcal skin infections.
4
Determine the appropriate management.
Supportive care with continuous positive airway pressure (CPAP) or supplemental oxygen is selected.
CPAP helps drive retained fluid out of the alveoli and supports functional residual capacity. Avoiding unnecessary antibiotics, antivirals, or buffer therapies is critical in managing this self-limiting condition.

Key Concept

Transient tachypnea of the newborn (TTN) presents with respiratory distress and characteristic radiographic findings (fluid in fissures) following cesarean delivery; management is supportive and must be distinguished from conditions requiring invasive therapies.
Estimated Time:1m 30s
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Topics

Neonatal Disorders

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