A 28-week gestation male infant is delivered via emergency cesarean section for placental abruption. Birth weight 1.2 kg. At 2 hours of life, the infant develops grunting, nasal flaring, and intercostal retractions. Oxygen saturation drops to 88% on room air. Chest X-ray shows a fine reticular granular pattern with air bronchograms and a ground-glass appearance. What is the most likely diagnosis?

Question

Accepted Answer

B. Respiratory Distress Syndrome (Hyaline Membrane Disease). ## Clinical Presentation & Diagnosis **Key Point:** Respiratory Distress Syndrome (RDS), also called Hyaline Membrane Disease (HMD), is the most common cause of respiratory distress in preterm infants and is caused by surfactant deficiency. ### Why This Case Fits RDS 1. **Gestational age:** 28 weeks is in the highest-risk window (22–32 weeks). Surfactant production begins at ~24 weeks but is insufficient until 34–36 weeks. 2. **Timing of onset:** Symptoms within the first 2 hours of life are classic for RDS; other conditions (TTN, meconium aspiration) typically present later or have different triggers. 3. **Clinical signs:** Grunting (attempt to maintain positive end-expiratory pressure), nasal flaring, intercostal retractions, and hypoxemia are hallmark features. 4. **Chest X-ray findings:** The fine reticular granular pattern with air bronchograms and ground-glass appearance is pathognomonic for HMD. This represents atelectasis alternating with hyperinflated alveoli due to uneven ventilation from surfactant deficiency. ### Pathophysiology **High-Yield:** Surfactant (a lipoprotein complex rich in phospholipids, especially dipalmitoylphosphatidylcholine [DPPC]) reduces surface tension in alveoli. Without it, alveoli collapse at end-expiration (atelectasis), requiring enormous pressure to re-expand them with each breath — leading to work of breathing, fatigue, and hypoxemia. ### Risk Factors for RDS | Factor | Impact | |--------|--------| | Prematurity (< 34 weeks) | Highest risk; surfactant immature | | Male sex | 1.5–2× higher risk than females | | Maternal diabetes | Delays fetal lung maturity | | Cesarean delivery (especially elective, without labor) | No thoracic compression to expel fetal lung fluid | | Perinatal asphyxia | Reduces surfactant synthesis | | Maternal hemorrhage / placental insufficiency | Fetal stress impairs maturation | ### Management Principles ```mermaid flowchart TD A[Preterm infant with RDS]:::outcome --> B{Antenatal corticosteroids given?}:::decision B -->|Yes, < 7 days before delivery| C[Reduced RDS severity & mortality]:::action B -->|No or > 7 days| D[Higher risk of severe disease]:::urgent A --> E[Postnatal management]:::action E --> F[Exogenous surfactant replacement]:::action E --> G[Respiratory support: CPAP or intubation]:::action E --> H[Oxygen titration to target SpO2]:::action F --> I[Improves lung compliance & oxygenation]:::outcome ``` **Clinical Pearl:** Antenatal corticosteroids (betamethasone or dexamethasone) given to the mother 24 hours to 7 days before preterm delivery significantly reduce RDS incidence and severity by accelerating fetal lung maturation. **Mnemonic: SURFACTANT** — **S**urface tension reduction, **U**neven ventilation (atelectasis), **R**eticular granular pattern (CXR), **F**etal immaturity, **A**ir bronchograms, **C**lassic in preterm, **T**iming early (first hours), **A**ntepartum steroids prevent, **N**eed exogenous replacement, **T**achypnea & grunting. **High-Yield:** Exogenous surfactant (e.g., beractant, poractant alfa) given via endotracheal tube within the first hours of life is the definitive treatment and dramatically improves survival and reduces chronic lung disease. ![Respiratory Distress Syndrome diagram](https://mmcphlazjonnzmdysowq.supabase.co/storage/v1/object/public/blog-images/explanation/3834.webp)

Answer

A. Transient Tachypnea of the Newborn

Answer

C. Meconium Aspiration Syndrome

Answer

D. Congenital Pneumonia

Explanation

Clinical Presentation & Diagnosis

Why This Case Fits RDS

Pathophysiology

Risk Factors for RDS

Management Principles

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Factor	Impact
Prematurity (< 34 weeks)	Highest risk; surfactant immature
Male sex	1.5–2× higher risk than females
Maternal diabetes	Delays fetal lung maturity
Cesarean delivery (especially elective, without labor)	No thoracic compression to expel fetal lung fluid
Perinatal asphyxia	Reduces surfactant synthesis
Maternal hemorrhage / placental insufficiency	Fetal stress impairs maturation