Overview
Definition:
Respiratory Distress Syndrome (RDS), also known as hyaline membrane disease, is a common cause of respiratory failure in premature infants, characterized by insufficient production of pulmonary surfactant.
Epidemiology:
RDS affects approximately 50% of infants born before 28 weeks gestation and 15-20% of infants born between 30-34 weeks
The incidence decreases significantly with gestational age
It is a leading cause of mortality and morbidity in preterm neonates.
Clinical Significance:
Effective management of RDS is critical for improving survival rates and reducing long-term pulmonary complications in preterm infants
Understanding the comparative efficacy and indications for CPAP versus early surfactant administration is paramount for pediatric residents preparing for DNB and NEET SS examinations.
Clinical Presentation
Symptoms:
Tachypnea (respiratory rate > 60 breaths/min)
Grunting respirations
Nasal flaring
Retractions (subcostal, intercostal, suprasternal)
Cyanosis (central)
Decreased air entry on auscultation
Apnea
Lethargy.
Signs:
Rapid, shallow breathing
Use of accessory muscles
Paradoxical breathing pattern
Crackles or diminished breath sounds on auscultation
Pallor
Poor peripheral perfusion
Hypotension
Bradycardia may occur in severe cases.
Diagnostic Criteria:
Clinical presentation of respiratory distress in a preterm infant, particularly with risk factors for prematurity
Chest X-ray findings typically show diffuse reticulogranular opacities (ground-glass appearance) with air bronchograms
Exclusion of other causes of neonatal respiratory distress.
Diagnostic Approach
History Taking:
Gestational age at birth is the most crucial factor
Maternal history including premature rupture of membranes, diabetes mellitus, and prenatal steroid use
Family history of RDS or neonatal respiratory issues
Details of delivery and immediate postnatal course
Presence of perinatal asphyxia.
Physical Examination:
Systematic assessment of respiratory effort, including respiratory rate, pattern, and presence of retractions
Auscultation for breath sounds, adventitious sounds (crackles, wheezes), and murmurs
Assessment of color, perfusion, and neurological status
Vital signs monitoring: temperature, heart rate, respiratory rate, blood pressure, and oxygen saturation.
Investigations:
Chest X-ray: Initial imaging of choice, revealing characteristic findings of RDS
Arterial Blood Gas (ABG): To assess oxygenation (PaO2), ventilation (PaCO2), and acid-base status (pH)
Complete Blood Count (CBC): To rule out sepsis
Blood Glucose: Hypoglycemia can worsen respiratory distress
Chest ultrasound: May be useful in equivocal cases.
Differential Diagnosis:
Transient Tachypnea of the Newborn (TTN): Often resolves within 24-48 hours, usually associated with C-section or maternal diabetes
Neonatal Pneumonia: Often presents with fever, purulent secretions, and may have focal consolidation on X-ray
Meconium Aspiration Syndrome (MAS): History of fetal distress or post-term infant, characteristic X-ray findings with patchy infiltrates
Congenital Anomalies: Such as diaphragmatic hernia or lung malformations.
Management
Initial Management:
Cardiorespiratory stabilization: ensure adequate airway, breathing, and circulation
Supplemental oxygen to maintain target saturation (e.g., 88-95%)
Thermal neutral environment
Close monitoring of vital signs, oxygenation, and ventilation
IV fluids and nutrition.
Continuous Positive Airway Pressure Cpap:
Non-invasive ventilation
Provides continuous positive pressure to the airways, preventing alveolar collapse and improving gas exchange
Typically initiated at 4-6 cm H2O
Nasal CPAP (nCPAP) is the preferred method
Can be delivered via nasal prongs or mask.
Early Surfactant Administration:
Administration of exogenous surfactant into the trachea, usually within the first few hours of life, often before or immediately after initiating respiratory support
Recommended for infants < 28-30 weeks gestation
Different preparations available (e.g., Beractant, Calfactant)
Given via intratracheal instillation, often using INSURE technique (INtubation-SURfactant-Extubation) or via Laryngeal Mask Airway (LMA).
Mechanical Ventilation:
Indicated if CPAP fails to maintain adequate oxygenation or ventilation
Various modes available (e.g., pressure-controlled ventilation, volume-controlled ventilation)
Synchronized intermittent mandatory ventilation (SIMV) or assist-control ventilation (ACV) are common
High-frequency oscillatory ventilation (HFOV) may be used for severe RDS.
Supportive Care:
Strict fluid and electrolyte balance
Nutritional support (enteral feeding if tolerated, parenteral nutrition otherwise)
Monitoring for complications like pneumothorax, air leak syndromes, and infection
Neurodevelopmental follow-up.
Comparative Strategies
Cpap Strategy:
CPAP alone as initial therapy
Offers respiratory support without intubation in many cases, reducing risks associated with mechanical ventilation
May be sufficient for milder RDS or later preterm infants
However, can lead to increased work of breathing if surfactant deficiency is severe.
Early Surfactant Strategy:
Prophylactic or early rescue surfactant administration, often with transient intubation
Proven to reduce mortality and morbidity in very preterm infants
May be combined with CPAP (e.g., LISA - Less Invasive Surfactant Administration, or minimally invasive surfactant therapy).
Evidence And Guidelines:
Numerous trials (e.g., Cochrane reviews) support the use of surfactant therapy for reducing RDS severity, mortality, and chronic lung disease
Current guidelines from organizations like the American Academy of Pediatrics (AAP) and European Academy of Pediatrics recommend early surfactant for infants born at < 28-30 weeks gestation
CPAP is recommended as initial treatment for infants with mild to moderate RDS and those > 28-30 weeks gestation.
Complications
Early Complications:
Pneumothorax
Pulmonary interstitial emphysema (PIE)
Bronchopulmonary dysplasia (BPD)/Chronic Lung Disease (CLD)
Patent ductus arteriosus (PDA)
Intraventricular hemorrhage (IVH)
Necrotizing enterocolitis (NEC)
Sepsis.
Late Complications:
Long-term respiratory issues including asthma-like symptoms and reduced lung function
Neurodevelopmental impairments
Vision and hearing deficits
Growth restriction.
Prevention Strategies:
Antenatal corticosteroids for mothers at risk of preterm birth
Avoiding prolonged rupture of membranes
Judicious use of oxygen
Prompt and appropriate respiratory support (CPAP, surfactant)
Prevention of nosocomial infections
Close monitoring and early intervention for complications.
Key Points
Exam Focus:
Gestational age is paramount in deciding management
Early surfactant (< 28-30 weeks) reduces mortality
CPAP is initial treatment for milder RDS and later preterm infants
Differentiate RDS X-ray findings from other neonatal lung diseases
Understand INSURE, LISA, and CPAP delivery methods.
Clinical Pearls:
Consider antenatal steroids for all mothers delivering preterm
Titrate oxygen to target saturation, avoiding hyperoxia
Monitor for signs of air leak
Early recognition of treatment failure guides escalation to mechanical ventilation
Surfactant is expensive
administer judiciously based on evidence.
Common Mistakes:
Delaying surfactant in very preterm infants
Over-oxygenation leading to retinopathy of prematurity
Underestimating the severity of RDS and delaying escalation of therapy
Inadequate fluid management
Misinterpreting chest X-rays or ABGs.