Write the risk factors for respiratory distress syndrome (RDS)s in newborn. What is the differential diagnosis of RDS? How will you manage respiratory distress syndrome in newborn?

Risk Factors for Respiratory Distress Syndrome (RDS) in Newborns

The primary risk factor for RDS is prematurity, as surfactant production is often inadequate before 34-36 weeks of gestation. However, several other factors can increase a newborn's susceptibility:

• Prematurity: The most significant risk factor. The earlier the gestational age, the higher the risk, as surfactant production is insufficient in immature lungs.
• Low Birth Weight: Often directly correlated with prematurity, increasing the risk.
• Maternal Diabetes: Infants of diabetic mothers may have delayed lung maturation and surfactant production.
• Cesarean Section without Labor: Babies born via elective C-section without prior labor may have a higher risk due to retained fetal lung fluid and potentially reduced stress-induced surfactant release.
• Male Sex: Male infants generally have a higher incidence of RDS compared to female infants.
• Perinatal Asphyxia: Episodes of oxygen deprivation during birth can damage lung cells and inactivate surfactant.
• Multiple Gestation: Twins or triplets are often born prematurely, increasing their risk.
• Cold Stress: Hypothermia can increase oxygen consumption and worsen respiratory distress.
• Acidosis and Hypoxia: These conditions can exacerbate surfactant deficiency and lung injury.
• Previous Infant with RDS: A family history of RDS can indicate a genetic predisposition or shared maternal risk factors.
• Certain Genetic Mutations: Rarely, mutations in genes encoding surfactant proteins (e.g., SP-B, SP-C) or surfactant transport proteins (e.g., ABCA3) can lead to surfactant deficiency even in term infants.

Differential Diagnosis of RDS

The signs and radiological appearances of RDS are not specific, and other causes of respiratory distress in newborns must be considered. A comprehensive evaluation is crucial to differentiate RDS from conditions with similar presentations.

Condition	Key Differentiating Features	Typical Onset	Chest X-ray Findings
Transient Tachypnea of the Newborn (TTN)	Usually affects term/late-preterm infants; mild to moderate distress; often resolves within 24-72 hours. Less severe than RDS.	Within minutes to hours after birth	Prominent vascular markings, fluid in interlobar fissures, hyperinflation, flattened diaphragms.
Neonatal Pneumonia/Sepsis	Can present with systemic signs (fever/hypothermia, lethargy, poor feeding), may have specific risk factors (e.g., prolonged rupture of membranes, maternal chorioamnionitis).	Variable, can be at birth or develop later	Patchy infiltrates, pleural effusion, or diffuse consolidation. May be similar to RDS, making cultures essential.
Meconium Aspiration Syndrome (MAS)	History of meconium-stained amniotic fluid; typically in term or post-term infants. Can cause chemical pneumonitis and airway obstruction.	Immediately after birth	Coarse, patchy infiltrates; hyperinflation; flattened diaphragms; sometimes pneumothorax.
Persistent Pulmonary Hypertension of the Newborn (PPHN)	Severe hypoxemia disproportionate to lung disease; often associated with MAS, sepsis, or RDS. Can be identified by echocardiography.	Within hours after birth	May be normal or show signs of underlying lung disease (e.g., MAS, RDS).
Congenital Heart Disease (CHD)	Cyanosis unresponsive to oxygen, heart murmur, abnormal pulses, cardiomegaly on X-ray. Screening with pulse oximetry helps detection.	Variable, can be at birth or develop later	Cardiomegaly, abnormal pulmonary vascularity, specific cardiac malformation signs.
Airway Obstruction/Malformations	Stridor, abnormal cry, localized respiratory sounds. (e.g., choanal atresia, tracheoesophageal fistula).	Immediately at birth	Specific findings related to obstruction (e.g., gasless abdomen in esophageal atresia).
Pneumothorax	Acute worsening of respiratory distress, asymmetry of chest movements, decreased breath sounds on one side.	Sudden onset	Air in pleural space, lung collapse on affected side.
Diaphragmatic Hernia	Scaphoid abdomen, mediastinal shift, bowel sounds in the chest, severe respiratory distress.	Immediately at birth	Bowel loops in the chest, mediastinal shift.

Management of Respiratory Distress Syndrome in Newborns

Effective management of RDS involves a multi-pronged approach, focusing on prevention, respiratory support, and surfactant replacement therapy, guided by national and international guidelines such as the Indian Academy of Pediatrics (IAP) Standard Treatment Guidelines 2022 and European Consensus Guidelines 2022.

1. Antenatal Management (Prevention)

• Antenatal Corticosteroids (ACS): Administration of corticosteroids (e.g., betamethasone or dexamethasone) to mothers at risk of preterm delivery (between 24-34 weeks of gestation, or up to 36+6 weeks in some cases) significantly accelerates fetal lung maturation and reduces the incidence and severity of RDS.
• Tocolytics: Short-term use of tocolytic drugs in very preterm pregnancies can delay delivery, allowing time for ACS to become effective and for in-utero transfer to a tertiary care center.

2. Delivery Room Management

• Stabilization: Careful resuscitation and stabilization, including maintaining normal body temperature (thermoregulation), preventing hypoxia, and avoiding hyperoxia. Initial oxygen concentration for resuscitation should be controlled using a blender (e.30 for babies <28 weeks, 0.21-0.30 for 28-31 weeks, and 0.21 for >32 weeks).
• Early Respiratory Support: Initiate Continuous Positive Airway Pressure (CPAP) from birth in all babies at risk of RDS who do not require intubation for stabilization, especially those less than 30 weeks of gestation.

3. Postnatal Management (Respiratory Support and Specific Therapy)

• Non-Invasive Respiratory Support:
  • Continuous Positive Airway Pressure (CPAP): The mainstay of non-invasive support, helping to keep alveoli open and improve lung volumes. Typically started at 6-8 cmH2O.
  • Non-invasive Positive Pressure Ventilation (NIPPV): Can be used to reduce the need for invasive mechanical ventilation in some infants.
  • High-Flow Nasal Cannula (HHHFNC): May be tried if low-flow nasal oxygen fails, providing heated and humidified air.
• Surfactant Replacement Therapy:
  • Early Rescue Surfactant: Administered to babies with RDS who require FiO2 >0.30 to maintain SpO2 >90% with a CPAP level of ≥6 cmH2O, preferably within 2 hours of birth. Poractant alpha (200 mg/kg initial dose) or beractant (100 mg/kg) are commonly used.
  • Administration Techniques:
    • Intubation-Surfactant-Extubation (INSURE) technique: Involves brief intubation for surfactant administration, followed by immediate extubation to CPAP.
    • Less Invasive Surfactant Administration (LISA) or Minimally Invasive Surfactant Therapy (MIST): Surfactant is given via a thin catheter inserted into the trachea while the infant remains on CPAP, avoiding mechanical ventilation.
  • Repeat Doses: A second and occasionally a third dose may be given if there is ongoing evidence of RDS (e.g., persistent high oxygen requirement) and other problems have been excluded.
• Mechanical Ventilation: Reserved for infants with severe RDS who fail non-invasive support, defined by persistent hypoxemia (FiO2 >0.6), respiratory acidosis (PaCO2 >60 mmHg, pH <7.2), or recurrent apnea. Patient-triggered ventilation with volume guarantee is considered optimal.
• Supportive Care:
  • Fluid and Electrolyte Management: Careful balance to prevent fluid overload and maintain electrolyte homeostasis.
  • Nutrition: Early enteral feeding when stable, or parenteral nutrition if necessary.
  • Thermoregulation: Maintaining a neutral thermal environment to minimize metabolic demand.
  • Antibiotics: Empirical antibiotics should be initiated, especially if sepsis is suspected, until blood cultures prove negative.
  • Monitoring: Continuous monitoring of oxygen saturation (SpO2 90-95%), heart rate, blood pressure, and blood gases.