A 28-week gestation female neonate born to a mother with rupture of membranes presents with respiratory distress within 2 hours of birth. Chest X-ray shows a ground-glass appearance with air bronchograms. Which drug is the first-line treatment for respiratory distress syndrome in this preterm infant?

Explanation

## Respiratory Distress Syndrome: First-Line Surfactant Therapy ### Clinical Context The clinical presentation—preterm birth at 28 weeks, respiratory distress within hours, and ground-glass appearance on CXR—is pathognomonic for Respiratory Distress Syndrome (RDS), caused by surfactant deficiency. ### Drug of Choice: Poractant Alfa **Key Point:** Poractant alfa is a natural (porcine-derived) surfactant and is the preferred first-line agent for RDS in preterm neonates. It is administered via endotracheal tube as an intra-pulmonary instillation. ### Mechanism of Action Surfactant replacement therapy works by: 1. Reducing surface tension at the air-liquid interface in alveoli 2. Restoring compliance and preventing alveolar collapse during expiration 3. Improving gas exchange and oxygenation ### Surfactant Preparations Available | Agent | Type | Source | Dosing | Notes | |-------|------|--------|--------|-------| | **Poractant alfa** | Natural | Porcine lung | 100–200 mg/kg/dose | **Gold standard; most potent** | | Beractant | Natural | Bovine lung | 100 mg/kg/dose | Effective; less potent than poractant | | Calfactant | Natural | Calf lung | 105 mg/kg/dose | Effective alternative | | Lucinactant | Synthetic | Lab-synthesized | 5.8 mL/kg/dose | Newer; less clinical experience | **High-Yield:** Poractant alfa has the highest phospholipid concentration and superior clinical outcomes compared to other surfactants. It is the DOC in most NEET PG curricula and Indian neonatal units. ### Timing and Administration - **Timing:** Administer as soon as RDS is diagnosed (within first 2 hours of life ideally) - **Route:** Endotracheal tube (requires intubation) - **Repeat doses:** May be given at 12 and 24 hours if respiratory support remains needed ### Clinical Pearl Surfactant replacement has reduced mortality and morbidity from RDS by ~40% since its introduction. Early administration (within 2 hours) yields better outcomes than delayed therapy. **Mnemonic:** **PALS** = Poractant alfa, Antenatal steroids, Lung recruitment, Supportive care — the pillars of RDS management. ### Contraindications & Precautions - Contraindicated in meconium aspiration syndrome (relative) - Monitor for transient hypoxemia during instillation - Requires mechanical ventilation capability [cite:Nelson Textbook of Pediatrics 21e Ch 102]