Infant respiratory distress syndrome in premature babies is due to deficiency of?

CGHS SSC - 2018

Child Health Nursing (Pediatrics)

Easy

Appeared in: CGHS SSC - 2018

Explanation

Infant Respiratory Distress Syndrome (IRDS) in premature infants is primarily caused by a deficiency of pulmonary surfactant.
Surfactant is a lipoprotein complex produced by type II alveolar cells that reduces surface tension in the alveoli, preventing them from collapsing during expiration.
Production of surfactant is often insufficient in infants born before 35 weeks of gestation, leading to alveolar collapse (atelectasis), impaired gas exchange, and respiratory distress.
The deficiency results in increased work of breathing, hypoxemia, and hypercapnia.

Option B: A deficiency in immunoglobulins increases the risk of infection but does not cause the primary mechanical lung failure seen in IRDS.
Option C: Elevated carbon dioxide (hypercapnia) is a consequence of the impaired gas exchange that occurs in IRDS, not the initial cause of the syndrome.
Option D: Low oxygen levels (hypoxemia) are a direct result of the alveolar collapse and poor gas exchange in IRDS, not the underlying cause.

Clinical Relevance

Nursing practice connection: Use the key finding related to Pathophysiology of Infant Respiratory Distress Syndrome (IRDS) to guide bedside assessment, documentation, and the next nursing action.
The cornerstone of IRDS management is replacing the missing substance via exogenous surfactant administration directly into the lungs through an endotracheal tube.
Nurses play a critical role in administering surfactant, monitoring for immediate improvements in oxygenation and lung compliance, and managing potential side effects like transient bradycardia or airway obstruction.
What if? If a mother at risk for preterm labor receives antenatal corticosteroids (e.g., betamethasone) before delivery, the risk and severity of IRDS in the infant are significantly reduced because the steroids accelerate fetal lung maturation and surfactant production.

How to Approach the Question

First, identify the key elements of the question: 'Infant respiratory distress syndrome' (the condition), 'premature babies' (the patient population), and 'deficiency of' (the cause).
Recall the core pathophysiology of IRDS. The name itself, 'respiratory distress', points to a lung problem, and its prevalence in 'premature' infants is a major clue.
Evaluate the options based on cause versus effect. Ask yourself, 'Does a lack of this substance cause the lung mechanics to fail, or is the abnormal level of this substance a result of the lung failure?'
Surfactant deficiency directly causes alveolar collapse. Low oxygen and high carbon dioxide are effects of this collapse.
Immunoglobulin deficiency relates to the immune system, not the primary mechanics of breathing, making it less likely to be the direct cause of IRDS.
This process of elimination and cause-and-effect analysis leads to 'Surfactant' as the correct underlying cause.

Concept Tested & Keywords

Concept Tested: Pathophysiology of Infant Respiratory Distress Syndrome (IRDS)
Stem keywords: Infant respiratory distress syndrome, premature babies, deficiency
Lead-in keywords: due to
Clinical cues: Age/sex group narrows the expected diagnosis, intervention, or normal reference range.

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