Last updated:
March 31, 2026
Bronchopulmonary dysplasia is a chronic lung disease affecting premature infants. It is characterised by parenchymal lung injury and arrested lung development.
It is diagnosed in:
- Infants ≤ 32 weeks of gestational age
- Require ≥ 28 days of oxygen exposure
Severity is assessed at 36 weeks postmenstrual age
| Severity | Description |
|---|---|
| Mild | No supplemental oxygen required at 36 weeks postmenstrual age |
| Moderate | < 30% needed oxygen at 36 weeks postmenstrual age |
| Severe | ≥ 30% oxygen or positive pressure ventilation needed at 36 weeks postmenstrual age |
Classification
| Term | Definition |
|---|---|
| Old bronchopulmonary dysplasia | This is due to barotrauma and oxygen toxicity. It is characterised by marked airway injury and fibrosis. |
| New bronchopulmonary dysplasia | This is seen in extremely preterm infants. It is characterised by arrested alveolar development, impaired vascular growth, and minimal fibrosis. |
Phases of lung development (EPCSA 7)
| Phase | Description |
|---|---|
| Embryonic (3 – 6 weeks) | Formation of lung buds and differentiation into trachea and bronchi |
| Pseudoglandular (7 – 17 weeks) | Branching of the bronchial tree, formation of the lung parenchyma and appearance of type II pneumocytes |
| Cannalicular (17 – 27 weeks) | Formation of lung periphery, increased vascularisation, appearance of type I pneumocytes and formation of blood-air barrier. This is the stage that is affected in new bronchopulmonary dysplasia |
| Saccular (27 – 36 weeks) | Formation of alveolar saccules. Surfactant becomes detectable in amniotic fluid |
| Alveolar (36 weeks – 8 years) | Formation of mature alveoli with their proliferation and expansion |
- Risk factors
- Prenatal – the factors can cause premature delivery or affect pulmonary development
- Lack of antenatal steroids
- Maternal smoking
- Chorioamnionitis
- Preeclampsia
- Hypoxia
- Genetic susceptibility
- Pulmonary hypoplasia
- Postnatal
- Prematurity – the most important risk factor
- Mechanical ventilation damage
- Barotrauma due to pressure
- Volutrauma due to volume
- Oxygen toxicity – due to the release of free radicals
- Sepsis
- Poor nutrition
- Pulmonary fluid overload, e.g., patent ductus arteriosus
- Prenatal – the factors can cause premature delivery or affect pulmonary development
- Pathophysiology
- Lung injury → inflammation → abnormal repair and remodelling → arrested lung development
- The final result is:
- Alveolar simplification (fewer and larger alveoli)
- Impaired vascular development
- Reduced surface area for gas exchange
- Patient history
- An infant born at ≤ 32 weeks of gestational age
- Persistent radiographic findings of parenchymal lung disease
- Requires respiratory support at 36 weeks postmenstrual age for ≥ 3 days to maintain arterial oxygen saturation at 90 -95%
- Signs and symptoms
- Tachypnoea
- Increased work of breathing
- Retractions
- Crackles
- Low oxygen saturation requiring persistent oxygen
- Poor feeding and weight gain
- Investigations
- Blood gas analysis
- Hypoxia
- Hypercapnia
- Respiratory acidosis
- Chest radiograph
- Hyperinflation
- Atelectasis
- Pulmonary oedema
- Interstitial changes
- Monitoring with pulse oximetry and transcutaneous CO2
- Echocardiography to screen for pulmonary hypertension at 36 weeks postmenstrual age
- Blood gas analysis
- Treatment
- Nutrition
- Breast milk + fortification
- 140 – 150 kcal/kg/day
- 3.5 – 4 g/kg/day proteins
- Vitamin A supplementation may reduce the risk of bronchopulmonary dysplasia
- Fluid management
- Restrict to 120 – 150 ml/kg/day to prevent pulmonary oedema
- Ventilation
- Non-invasive ventilation (CPAP) is preferred over intubation
- Caffeine can be used to stimulate the respiratory effort
- Minimise barotrauma and volutrauma
- Early extubation is important
- Oxygen
- Target SpO2 of 88 – 94%
- Avoid hypereoxia
- Corticosteroids (dexamethasone and hydrocortisone)
- Given to reduce inflammation in severe, ventilator-dependent infants
- Given to mothers with signs of premature labour at less than 35 weeks of gestation to speed up lung development
- Diuretics to improve short-term lung mechanics
- Bronchodilators for acute bronchospasm
- Monthly palivizumab injection to protect against RSV and bronchiolitis
- Nutrition
- Complications
- Pulmonary hypertension
- Cor pulmonale
- Recurrent infections
- Systemic hypertension
- Left ventricular hypertrophy or dysfunction
- Motor and language delay
- Poor growth
- Reactive airway disease (asthma)
- Prognsis
- Persists into adulthood
- 50% are readmitted in the first year
- Carries a long-term risk for asthma, emphysema, and exercise intolerance