Respiratory Distress Syndrome

Respiratory Distress Syndrome

Respiratory Distress Syndrome

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RDS Intro - Lungs Gasping

  • Definition: Acute lung disease of premature infants, causing respiratory distress shortly after birth.
  • Core Defect: Insufficient pulmonary surfactant production and secretion by Type II pneumocytes.
  • Pathophysiology:
    • Surfactant ↓ → Alveolar surface tension ↑ → Diffuse alveolar atelectasis.
    • Consequences: ↓ Lung compliance (stiff lungs), ↑ Work of breathing.
    • Gas Exchange: Ventilation-Perfusion (V/Q) mismatch → Hypoxemia, Hypercarbia, Respiratory acidosis.

⭐ RDS is also known as Hyaline Membrane Disease due to the characteristic eosinophilic membranes (fibrin, cellular debris) lining alveoli seen on histology.

Infant Respiratory Distress Syndrome Comparison

RDS Risks - Danger Signals

  • Major Risk Factors (↑ RDS Incidence/Severity):
    • Prematurity: Greatest risk, esp. < 34 weeks, severe < 28 weeks.
    • Maternal Diabetes: Impairs surfactant production.
    • Cesarean Section: Particularly elective, without labor.
    • Male Gender: Slower lung maturation.
    • Perinatal Asphyxia: Damages type II pneumocytes.
    • Family History/Genetics: Previous sibling with RDS.
  • Mitigating Factors (↓ RDS Risk):
    • Antenatal Corticosteroids: Stimulate surfactant synthesis.
    • Chronic Intrauterine Stress: (e.g., PIH, IUGR, PROM) accelerates lung maturity.
    • Female Gender.

⭐ Maternal diabetes increases fetal insulin, which antagonizes cortisol and inhibits surfactant synthesis, significantly ↑ RDS risk.

RDS Signs & Dx - Spotting Trouble

  • Clinical Manifestations (Onset: birth to hours):
    • Tachypnea (respiratory rate >60/min)
    • Expiratory grunting (to maintain Functional Residual Capacity - FRC)
    • Nasal flaring, intercostal & subcostal retractions
    • Cyanosis (central, often requiring supplemental O₂)
    • Auscultation: Decreased air entry, fine end-inspiratory crackles
  • Diagnostic Evaluation:
    • Arterial Blood Gas (ABG): Hypoxemia ($P_aO_2$ < 50 mmHg in room air), hypercarbia ($P_aCO_2$ > 65 mmHg), respiratory or mixed acidosis.
    • Chest X-ray (CXR): Key for diagnosis & severity.
      • Bilateral, diffuse reticulogranular ("ground-glass") opacities
      • Prominent air bronchograms (dark, air-filled bronchi against opaque alveoli)
      • Low lung volumes / bell-shaped thorax

⭐ Chest X-ray showing a "white-out" appearance in severe RDS indicates extensive atelectasis and poor prognosis. Chest X-ray: Neonatal Respiratory Distress Syndrome

RDS Management - Breathing Easy

  • Goal: Adequate oxygenation & ventilation, minimize lung injury.
  • Supportive Care:
    • Thermoregulation: Maintain neutral thermal environment.
    • Fluid & Nutrition: IV fluids, early parenteral/enteral nutrition.
    • Monitor: Vitals, blood gas, electrolytes.
  • Respiratory Support:
    • Nasal CPAP (nCPAP): Preferred initial mode if spontaneous breathing.
    • Surfactant Replacement: Via endotracheal tube. Consider early rescue.
      • 📌 INSURE (Intubate-Surfactant-Extubate).
    • Mechanical Ventilation: If CPAP fails or apnea. Gentle ventilation strategies.

⭐ Antenatal corticosteroids (e.g., Betamethasone 2 doses 12mg IM 24h apart) significantly reduce RDS incidence and severity when given between 24-34 weeks gestation.

RDS Complications - Future Watch

  • Acute Risks:
    • Air Leaks: Pneumothorax, Pulmonary Interstitial Emphysema (PIE).
    • Hemorrhage: Intraventricular (IVH), pulmonary.
    • Infection: Nosocomial sepsis.
    • Cardiovascular: Patent Ductus Arteriosus (PDA), hypotension.
  • Long-term Outlook (Future Watch):
    • ⭐ Bronchopulmonary Dysplasia (BPD) is a major long-term complication, defined as oxygen dependency at 36 weeks postmenstrual age.

    • Retinopathy of Prematurity (ROP): Risk with prolonged O₂ therapy.
    • Neurodevelopmental Impairment (NDI): Includes cerebral palsy, significant cognitive, motor, or sensory deficits.
    • Chronic Respiratory Morbidity: Increased risk of asthma, recurrent wheezing, and respiratory infections.

High-Yield Points - ⚡ Biggest Takeaways

  • RDS arises from surfactant deficiency in preterm infants, leading to progressive atelectasis.
  • CXR hallmark: Diffuse bilateral reticulogranular ("ground-glass") pattern and air bronchograms.
  • Clinical onset soon after birth: tachypnea, audible grunting, significant retractions, nasal flaring, cyanosis.
  • Prevention: Antenatal corticosteroids administered to mothers at risk of premature delivery.
  • Management: Intratracheal exogenous surfactant and respiratory support (CPAP or mechanical ventilation).
  • Monitor for common complications: PDA, Bronchopulmonary Dysplasia (BPD), IVH, ROP.

Practice Questions: Respiratory Distress Syndrome

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Which of the following is NOT included in the resuscitation of a neonate with HR < 60/min?

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Flashcards: Respiratory Distress Syndrome

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_____-onset sepsis in neonates is characterised by respiratory distress and pneumonia

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_____-onset sepsis in neonates is characterised by respiratory distress and pneumonia

Early

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