Summary

Bronchopulmonary Dysplasia (BPD), also known as Chronic Lung Disease of Prematurity (CLD), is a chronic lung condition affecting preterm infants, particularly those born at extremely low gestational ages (<28 weeks) or extremely low birth weights (<1000g). It is characterised by arrested lung development and persistent oxygen requirement beyond 28 days of life or at 36 weeks postmenstrual age (PMA). BPD is a consequence of the immature lung's response to injury from mechanical ventilation (volutrauma/barotrauma), oxygen toxicity, and inflammation, often on a background of infection (chorioamnionitis) and inadequate nutrition. Prevention strategies (antenatal steroids, surfactant, gentle ventilation, caffeine) have reduced severe BPD, but the condition remains a major cause of morbidity in survivors of extreme prematurity. Long-term management includes respiratory support, prevention of RSV infection (Palivizumab), nutrition optimisation, and follow-up for pulmonary hypertension and neurodevelopmental outcomes.

Key Facts

• Definition (NICHD): Need for supplemental oxygen for ≥28 days. Severity assessed at 36 weeks PMA.
• Risk Factors: Extreme prematurity (<28 weeks), Low birth weight, Mechanical ventilation, High FiO2, Chorioamnionitis, PDA, Sepsis.
• Pathophysiology: Arrested alveolar and vascular development. Inflammation. Fibrosis (in severe cases).
• Prevention: Antenatal Corticosteroids, Surfactant, Caffeine, Gentle Ventilation (CPAP, Volume-Targeting), Vitamin A.
• Management: Respiratory support (Home O2), Diuretics, Postnatal Corticosteroids (Carefully), Nutrition, RSV Prophylaxis.
• Prognosis: Many improve by age 2-3. Some have persistent airway disease. Risk of Pulmonary Hypertension.

Clinical Pearls

"Old BPD vs New BPD": "Old BPD" (Northway, 1967) described severe lung injury with fibrosis in larger preterm infants on high ventilator settings. "New BPD" (post-Surfactant era) is primarily arrest of lung development in extremely preterm infants, with fewer fibrotic changes.

"36 Weeks PMA is the Key Timepoint": Severity of BPD is assessed at 36 weeks corrected gestational age based on oxygen requirement.

"Caffeine Saves Lungs": Caffeine citrate reduces the risk of BPD (CAP Trial). It is a key preventive intervention for very preterm infants.

"RSV is the Enemy": Infants with BPD are at very high risk of severe RSV bronchiolitis. Palivizumab (Synagis) prophylaxis is critical during RSV season.

Why This Matters Clinically

BPD is one of the most common serious complications of prematurity, affecting long-term respiratory health, growth, and neurodevelopment. Prevention is key. Understanding the pathophysiology and evidence-based management (gentle ventilation, avoiding O2 toxicity, caffeine, nutrition) can reduce the burden of this disease.

NICHD 2001 Definition

The standard diagnostic criteria.

• Diagnosis: Supplemental oxygen requirement for ≥28 cumulative days.
• Severity Assessment: At 36 weeks PMA (or discharge if earlier) for infants <32 weeks GA. At 56 days postnatal age for infants ≥32 weeks GA.

Severity Grading (at 36 weeks PMA)

Investigations

Evidence-Based Prevention Strategies

Pulmonary Complications

Non-Pulmonary Complications

Prognosis

Prognostic Factors

Adult Respiratory Outcomes (Long-Term Follow-Up Studies)

Key Exam Tips (For Exams)

Post-Discharge Surveillance

Home Oxygen Weaning

Key Guidelines

Landmark Trials

Scenario 1:

• Stem: A 25-week gestation infant is now 36 weeks PMA and requires 28% FiO2. What is the diagnosis and severity?
• Answer: Bronchopulmonary Dysplasia (BPD). Severity: Moderate (Requires O2 <30% at 36 weeks PMA).

Scenario 2:

• Stem: What interventions prevent BPD in extremely preterm infants?
• Answer: Antenatal Corticosteroids, Surfactant, Caffeine Citrate, Early CPAP (Avoid intubation if possible), Volume-Targeted Ventilation, Judicious Oxygen Use (Target SpO2 91-95%), Vitamin A.

Scenario 3:

• Stem: Why is Caffeine important in BPD prevention?
• Answer: Caffeine Citrate (CAP Trial) reduces apnoea, allows earlier extubation, has anti-inflammatory effects, and significantly reduces the combined outcome of BPD or Death.

Scenario 4:

• Stem: A mother asks why her baby with BPD is being given monthly injections. Explain.
• Answer: Your baby is receiving Palivizumab (Synagis). It's an antibody that protects against RSV – a virus that causes bronchiolitis. Babies with BPD are at very high risk of severe RSV infection, so we give this monthly during winter to prevent it.

Scenario 5:

• Stem: What is the difference between "Old BPD" and "New BPD"?
• Answer: Old BPD (Northway 1967) was seen in larger preterm infants with severe ventilator-induced lung injury and fibrosis. New BPD affects extremely preterm infants (<28 weeks) and is characterised by arrested alveolar development (Simplified, larger alveoli) with less fibrosis, due to the use of Surfactant and gentler ventilation.

What is BPD?

Bronchopulmonary Dysplasia (BPD), also called Chronic Lung Disease of Prematurity, is a lung condition that affects babies born very early. Their lungs are not fully developed when they are born, and the treatments used to help them breathe (like oxygen and breathing machines) can sometimes cause damage or slow down lung growth.

Why did my baby get BPD?

Babies born very early (before 28 weeks) have immature lungs. The lungs need oxygen and sometimes a breathing machine to survive, but these can cause inflammation. Your baby's lungs are growing, but they need time and support to catch up.

What is the treatment?

• Oxygen: Some babies need extra oxygen at home until their lungs grow stronger.
• Medicines: Diuretics (water pills) can help with fluid in the lungs. Sometimes steroids are used.
• RSV Protection: A monthly injection during winter protects against a virus that can be very dangerous for babies with BPD.
• Good Nutrition: Calories help your baby grow, and growing helps the lungs heal.

Will my baby get better?

Most babies with BPD improve as they grow. The lungs continue to develop for the first few years of life. Some children have ongoing breathing problems like wheezing, but many do very well.

Key Counselling Points

1. Lung Growth Takes Time: "Your baby's lungs will continue to grow and heal over the first 2-3 years."
2. RSV is Dangerous: "Please keep your baby away from people with colds. The monthly injection protects against the most dangerous virus."
3. Avoid Smoke: "Second-hand smoke makes lung problems much worse."
4. Nutrition is Key: "Good feeding and weight gain help the lungs grow."
5. Follow-Up is Crucial: "Regular check-ups help us wean oxygen and catch any problems early."

Discharge Criteria for Home Oxygen

When can infants go home on oxygen?

Avoiding Common Pitfalls

Oxygen Saturation Targeting: The Debate

Summary of major trials.

Current Practice: Most units target 91-95% (Balance between avoiding oxygen toxicity and preventing mortality).

Parents' Questions Answered

Special Populations

• William Northway (1967): First described BPD in a landmark paper.
• Original Case Series: 32 infants with RDS who survived with O2 and mechanical ventilation.
• Findings: Severe lung injury: Fibrosis, Airway smooth muscle hypertrophy, Emphysematous changes.
• Terminology: Named "Bronchopulmonary Dysplasia" – dysplasia = abnormal growth.
• Modern Era: The condition we see today ("New BPD") is different – milder histology but affects more vulnerable, extremely preterm infants.