Broncho Pulmonary Dysplasia (BPD) is also known as

Chronic lung disease of premature babies: This term highlights that the condition primarily affects infants born before their due date.

Chronic lung disease of infancy: This is a broader term, indicating the long-term nature of the lung problems developing in early life.

Neonatal chronic lung disease: This emphasizes the presence of a persistent lung condition during the newborn period (neonatal period).

Respiratory insufficiency: This describes the core problem – the lungs are not able to adequately perform their function of providing oxygen and removing carbon dioxide.

Bronchopulmonary dysplasia (BPD) is a type of long-lasting lung problem that occurs in newborns. It is most commonly seen in babies who are born too early (premature) and require extra oxygen to help them breathe. These infants’ lungs are often underdeveloped and vulnerable to injury.

Bronchopulmonary dysplasia (BPD) is a continuing or long-term breathing problem that shows up on chest X-rays as uneven and spread-out areas of denser tissue or lungs that appear solid instead of having the normal air spaces.

In BPD, damage occurs to the lungs and the airways (bronchi). This damage leads to the abnormal development or destruction (dysplasia) of the tiny air sacs in the lungs called alveoli, which are essential for gas exchange.

Causes of Bronchopulmonary Dysplasia

Supplemental oxygen and mechanical ventilation in prematurity: Premature babies often require assistance with breathing because their lungs are underdeveloped. This support typically involves a mechanical ventilator or supplemental oxygen. However, providing this breathing assistance for an extended period can unfortunately harm their delicate, immature lungs, often leading to bronchopulmonary dysplasia. The pressure from the ventilator and high concentrations of oxygen can be damaging.

Prolonged high oxygen delivery in premature infants: When premature infants receive high levels of oxygen for a long time, it can cause inflammation and injury to the small airways (called bronchioles) and the walls between the air sacs (alveoli) in their lungs. This damage can lead to scarring and ultimately reduce the lung’s ability to properly oxygenate the blood, resulting in a lack of oxygen in the body (hypoxemia).

Vitamin A deficiency: Adequate Vitamin A is important for lung development. A lack of this essential vitamin can contribute to the risk of developing BPD in premature infants.

Lung infections such as pneumonia: Infections in the lungs, like pneumonia, can further damage the already vulnerable lungs of premature infants, increasing the likelihood of developing BPD.

Congenital (present at birth) malformations of the lung: In some cases, babies are born with structural abnormalities in their lungs. These pre-existing issues can make the lungs more susceptible to damage and the development of BPD.

Pathophysiology

The way bronchopulmonary dysplasia develops is intricate and still not fully understood. Essentially, BPD arises from various damaging factors that injure the small airways of the lungs. These injuries disrupt the normal process of alveolarization, which is the formation and maturation of the tiny air sacs (alveoli) responsible for gas exchange in the lungs. This disruption leads to alveolar simplification, meaning there are fewer and larger alveoli instead of many small ones. This reduction in the number of alveoli decreases the total surface area available for oxygen and carbon dioxide exchange.

It’s crucial to understand that the development of the air sacs (alveoli) and the blood vessels in the lungs are closely linked. Damage to one can negatively affect the development of the other. If the lungs are injured during a critical phase of their growth, it can result in significant long-term problems with how the lungs function.

Pathogenesis

In the lungs, BPD injures both the already present air sacs (alveoli) and those that are still developing. Furthermore, the tiny blood vessels that surround these air sacs can also be damaged. This damage can make it harder for blood to flow through the lungs. The fewer healthy alveoli an infant has, the longer they might need support from a breathing machine (ventilator), which unfortunately can cause even more harm to their lungs.

Over time, increased pressure within the blood vessels of the lungs and between the heart and lungs can lead to a condition called pulmonary hypertension. In severe cases, this can put so much strain on the heart that it can lead to heart failure. Babies with BPD may also struggle with feeding, which can slow down their overall development.

Clinical Features

• Tachypnea: Rapid breathing rate.

• Tachycardia: Fast heart rate.

• Increased respiratory effort: The baby works harder to breathe. This can be seen as the chest pulling in between the ribs (retractions), the nostrils widening with each breath (nasal flaring), and a grunting sound during breathing.

• Frequent desaturations: Repeated drops in blood oxygen levels.

• Labored breathing: Breathing appears difficult and strained.

• These babies are often born very prematurely, have a very low weight at birth, and may lose a significant amount of weight in the first 10 days of life.

• Wheezing: A whistling sound heard when the baby breathes out.

• The ongoing need for extra oxygen even after the baby reaches 36 weeks of gestational age (the time they would have been born if full-term).

• Difficulty feeding: Problems with taking in enough nutrition.

• Repeated lung infections: Frequent infections in the lungs that may require the baby to be admitted to the hospital.

• Bluish color around the mouth or lips, indicating low oxygen levels.

• Frequent alarms from the breathing monitor (apnea monitor) and/or the oxygen level monitor (pulse oximeter).

Diagnosis / Investigation

Diagnosing BPD involves a doctor’s assessment of the baby, considering how premature they were, and if they still need oxygen after about 2 weeks of age.

• Arterial blood gas (ABG) levels: A blood test to measure the oxygen and carbon dioxide levels in the blood.

• Pulmonary function tests: Tests to evaluate how well the lungs are working (though these are often difficult to perform in very young infants).

• Chest radiography: An X-ray of the chest to look at the structure of the lungs.

• High-resolution chest computed tomography scanning: A more detailed type of X-ray that provides cross-sectional images of the lungs.

• Chest magnetic resonance imaging: Another imaging technique that uses magnetic fields and radio waves to create detailed images of the lungs.

• Echocardiography: An ultrasound of the heart to assess its structure and function, and to check for pulmonary hypertension.

Differential Diagnosis

Other conditions that might look like BPD need to be considered:

• Airway Injury: Damage to the breathing tubes.

• Nosocomial Infection: An infection acquired in the hospital.

• Patent Ductus Arteriosus (PDA): A heart condition where a blood vessel that should close after birth remains open.

• Pediatric Hypertension: High blood pressure in children.

• Pediatric Pneumonia: Lung infection in children.

• Pediatric Subglottic Stenosis Surgery: Narrowing of the airway below the vocal cords.

• Pulmonary Atelectasis: Collapse of part or all of a lung.

• Tracheomalacia: Weakness of the cartilage in the windpipe.

Management of Broncho Pulmonary Dysplasia

There isn’t a cure for BPD, so treatment focuses on supporting the baby’s lungs, minimizing further damage, and allowing the lungs to heal and grow. Babies with BPD often need to be cared for in the hospital where they can be watched closely.

• Surfactant replacement with oxygen supplementation: Providing a substance (surfactant) that helps the air sacs in the lungs stay open, along with extra oxygen.

• Continuous positive airway pressure (CPAP): Delivering slightly pressurized air through a mask or nasal prongs to help keep the airways open.

• Mechanical ventilation: Using a machine to help the baby breathe.

• Treatment of the maternal inflammatory conditions and infections, such as chorioamnionitis: Addressing infections or inflammation in the mother during pregnancy.

• Diet:

  • Making sure the baby gets enough protein, carbohydrates, fat, and essential vitamins like vitamin A.

  • Starting with small amounts of feeding through a tube, gradually increasing the volume to help the baby tolerate feedings and get the necessary nutrition.

• Medical treatment:

  • Diuretics: Medications that help remove excess fluid from the lungs (for example, furosemide).

  • Bronchodilators: Medicines that relax the muscles around the airways, making it easier to breathe. These are usually given as a mist through a mask using a nebulizer or with an inhaler and spacer (for example, salbutamol, caffeine citrate, theophylline, ipratropium bromide).

  • Corticosteroids: Medications that reduce inflammation in the lungs. They can help reduce swelling in the windpipe and decrease mucus production. Like bronchodilators, they are often given as a mist with a mask using a nebulizer or an inhaler (for example, dexamethasone).

  • Vitamins: Providing necessary vitamins, such as vitamin A.

  • Keeping the baby warm.

  • Viral immunization: Giving vaccines to protect against respiratory infections, especially respiratory syncytial virus (RSV), as children with BPD are more at risk.

  • Cardiac Medications: Some babies with BPD may need special medications to help relax the muscles around the blood vessels in the lungs, improving blood flow and reducing strain on the heart.

Complications

• Difficulty feeding and reflux: Problems with eating and the backflow of stomach contents.

• Pulmonary hypertension: High blood pressure in the lungs.

• Hypercapnia: Too much carbon dioxide in the blood.

• Increased bronchial secretions: Producing more mucus in the airways.

• Hyperinflation: Over-expansion of the lungs.

• Frequent lower respiratory infections: Recurring infections in the lower airways.

• Delayed growth & development: Slower progress in physical growth and developmental milestones.