Respiratory Distress Syndrome (RDS/ HMD)
Definition
Pathophysiology
Risk Factors
Clinical Features
Signs
Investigations
Prevention
Treatment
Complications
Source
Toronto Notes 2012
- Aka Hyaline Membrane Disease (HMD)
- Insufficient surfactant production
Pathophysiology
- Surfactant deficiency --> poor lung compliance due to high alveolar surface tension --> atelectasis --> decreased surface area for gas exchange --> hypoxia + acidosis --> respiratory distress
- There is usually sufficient surfactant production by 36 wks GA
Risk Factors
- Prematurity
- Low birth weight
- Maternal diabetes: insulin inhibits the cortisol surge necessary for surfactant synthesis
- C-section without labour
- Asphyxia, meconium aspiration
- Acidosis, sepsis
- Male sex
- Hypothermia
- Second born twin
Clinical Features
Signs
- Respiratory distress
Investigations
- CXR: (↓ aeration and lung volumes, ground glass appearance, air bronchograms)
Prevention
- Steroid therapy for mothers who are at risk of preterm birth
- Monitor lecithin:sphingomyelin (LIS) ratio with amniocentesis, LIS >2:1 indicates lung maturity
- Prophylactic surfactant (<28/40)
Treatment
- Supportive
- CPAP, or intubation and mechanical ventilation
- Endotracheal surfactant administration
Complications
- Bronchopulmonary dysplasia
- Pulmonary air leaks (pneumothorax)
Source
Toronto Notes 2012