What is Bronchopulmonary Dysplasia?
The term ‘bronchopulmonary dysplasia’ (BPD) was first used in 1967 by Northway and his team. They used this term to describe long-term lung damage caused by severe trauma and oxygen injury in premature babies that needed mechanical help to breathe. Even though there have been considerable improvements in the care of premature babies over the past few decades, including new medicines and gentler methods of ventilation, BPD still remains quite common.
These advancements have led to the survival of extremely underweight newborns and this has altered some of the features of BPD. In 1999, Jobe introduced the term “new BPD” to describe the chronic lung disease seen in premature babies at that time. This “new BPD” showed much less damage to the airways and minimal internal scarring of the lungs compared to the previous form of BPD. The earlier form of BPD resulted in abnormally developed small blood vessels and simple alveoli, which are tiny air sacs in the lungs.
What Causes Bronchopulmonary Dysplasia?
Bronchopulmonary dysplasia is a complex health problem that is affected by a range of elements before and after birth, concerning both the mother and the baby.
Factors before birth that could lead to bronchopulmonary dysplasia include:
1. Not receiving steroidal medicines during pregnancy.
2. The mother smoking.
3. High blood pressure caused by pregnancy, also known as preeclampsia.
4. A lack of oxygen, or hypoxia.
5. The mother having an infection, including one known as chorioamnionitis.
6. A family history of certain conditions, or genetic factors.
7. Any birth defects resulting in the lungs not developing fully.
Meanwhile, the factors after birth playing a role in developing bronchopulmonary dysplasia in premature babies are:
1. The lungs not having fully matured.
2. Poor nutritional intake.
3. The need for a ventilator to assist with breathing.
4. Injury caused by too much oxygen.
5. Infections or widespread inflammation, known as sepsis.
Risk Factors and Frequency for Bronchopulmonary Dysplasia
Bronchopulmonary Dysplasia (BPD) is a disease that varies widely from place to place. This is due to differing medical practices, management styles, and definitions of the disease. BPD is most commonly found in babies born earlier than expected and those with low birth weight. In fact, research shows that 40 to 68% of very low birth weight babies (those weighing less than 1500 grams) are diagnosed with BPD, depending on the particular definition of BPD used. It’s important to note that the earlier the baby is born, the greater the likelihood of BPD occurring. Other risk factors that increase the chance of developing BPD are being male, low birth weight, white ethnicity, poor growth rate, and a family history of asthma.
- BPD varies greatly in occurrence due to differences in medical practices, management methods, and disease definitions.
- BPD is most common in babies born prematurely and those with low birth weights.
- Research shows 40 to 68% of very low birth weight infants (those under 1500 grams) may develop BPD.
- The risk of BPD increases the earlier a baby is born.
- Other risk factors for BPD include being male, low birth weight, white ethnicity, slow growth, and having a family history of asthma.
Signs and Symptoms of Bronchopulmonary Dysplasia
Bronchopulmonary dysplasia (BPD) in babies can vary a lot. It all depends on how severe the disease is. Some babies might need help with their breathing, while others are okay without it. Some babies might breathe much faster than normal. Sometimes, if there’s a lot of fluid in the lungs, symptoms might include signs of struggle to breathe. Symptoms may appear as pulling in of the chest and neck muscles during breathing, a crackling sound when the baby is breathing (rales), or just an overall increased effort to breathe.
- Need for respiratory support (breathing help)
- Increased breathing rate
- Struggle to breathe
- Pulling in of chest and neck muscles while breathing
- A crackling sound when breathing
- Increase in effort to breathe
Testing for Bronchopulmonary Dysplasia
If a doctor suspects a patient may have bronchopulmonary dysplasia (BPD), they will conduct several tests. These might include a blood gas test and a chest X-ray, as well as checking the patient’s nutritional status. An arterial blood gas test might show low oxygen levels, high carbon dioxide levels, or acidosis. Continuous pulse oximetry is also often used to ensure oxygen levels stay within healthy ranges. Additionally, some medical centers use transcutaneous carbon dioxide monitoring to assess a baby’s breathing.
A chest X-ray can reveal a variety of potential signs of BPD – things like low lung volume, overinflation of the lungs, areas of decreased or absent air in the lungs, fluid accumulation, or damage to the lung tissue. In some cases, a high-resolution CT scan may be used as it can reveal abnormalities that an X-ray might not pick up. If BPD is moderate or severe, an echocardiogram should be performed at 36 weeks postmenstrual age (PMA) to screen for pulmonary hypertension, a condition of high blood pressure in the lungs. This is important because BPD is often associated with high rates of illness and death.
The diagnosis of BPD itself depends on the age of the baby, the amount of time the baby has been exposed to oxygen, and whether the baby requires oxygen at 36 weeks PMA. The National Institute of Child Health and Human Development (NICHD) has provided a definition of BPD which helps doctors diagnose it based on the severity at 36 weeks PMA. However, this definition has been found to have limitations and doesn’t adequately predict respiratory outcomes, and so a revision is proposed, although it’s yet to be finalized.
Treatment Options for Bronchopulmonary Dysplasia
The main goal in treating infants with bronchopulmonary dysplasia (BPD), a chronic lung disease, is to support them as their lungs grow, minimize further lung damage, enhance lung function, and recognize any complications. Here are some common approaches to managing the care of these infants:
1. Nutrition: Infants with BPD need extra energy to help their lungs grow and repair. They might need around 140 to 150 calories per kilogram per day and protein intake from 3.5 to 4 grams per kilogram per day. Breast milk is the best choice but can be fortified with commercial milk fortifiers to supplement calories if needed. Early supplementation of vitamin A can reduce the chance of BPD by 7%.
2. Fluid restriction: Depending on the seriousness of their lung disease, infants’ fluid intake may need to be limited to around 120 to 150 milliliters per kilogram per day. This restriction can improve lung function by preventing fluid accumulation in the lungs and improving oxygen exchange. But the evidence backing this method is sketchy.
3. Minimizing lung injury from ventilators: Whenever possible, non-invasive ventilation is the first choice. If mechanical ventilation is a must, precautions should be taken to avoid lung injury. Early removal from the ventilator can lower the chances of developing BPD.
4. Minimizing injury from oxygen: High oxygen levels are a significant contributor to BPD. There is a debate over what the ideal target ranges should be. One approach is to maintain oxygen saturation levels between 88-94%.
5. Medications:
– Corticosteroids: These have been used to improve lung function and reduce swelling and the need for mechanical ventilation. However, the worry about long-term brain development has led to its use mainly in infants with severe BPD needing high levels of oxygen and ventilator support.
– Diuretics: Drugs such as thiazides and loop diuretics are usually given to infants relying on ventilators with increasing oxygen pressure needs. These medicines help short-term lung function but the benefits do not appear to be long-lasting.
– Bronchodilators: These drugs can reduce resistance in the airways and improve lung compliance. However, they do not seem to improve long-term outcomes. They should mainly be used to manage sudden episodes of airway restriction in older infants who rely on ventilators.
What else can Bronchopulmonary Dysplasia be?
- Collapsed lung (otherwise known as Pulmonary Atelectasis)
- Lung infection (Pneumonia)
- High blood pressure in the lungs (Pulmonary Hypertension)
- Weak windpipe (Tracheomalacia)
- Air pockets in the lungs (Pulmonary Interstitial Emphysema)
What to expect with Bronchopulmonary Dysplasia
Bronchopulmonary dysplasia (BPD) is a long-term illness that continues even after you leave the hospital and lasts into adulthood. Babies with BPD have a 50% chance of returning to the hospital in their first year of life. They also have a higher chance of developing conditions like asthma, emphysema, and a serious lung infection known as RSV bronchiolitis. This disease also impacts their growth and mental development. Very low birth weight babies with BPD are more likely to experience delays in developing movement skills and language.
Babies with BPD also have a higher risk of developing heart and lung-related issues like pulmonary hypertension (a type of high blood pressure that affects the arteries in your lungs), cor pulmonale (a condition where the right side of the heart fails), and systemic hypertension (high blood pressure). A recent study reported that about 20% of babies with BPD, and up to 40% of those with severe forms of the disease, suffer from pulmonary hypertension. Another study showed that 8 to 25% of extremely low birth weight babies (those born weighing less than 1000g) are affected by BPD-associated pulmonary hypertension. Earlier studies have also shown that within 2 years, 26 to 47% of patients with this condition experience serious health issues.
Possible Complications When Diagnosed with Bronchopulmonary Dysplasia
Bronchopulmonary dysplasia (BPD) is a common health issue often seen in prematurely born babies. This condition can lead to various other complications, including:
- Increased blood pressure throughout the body (Systemic hypertension)
- Negative effects on the baby’s brain and neurological development (Poor neurodevelopmental outcome)
- High blood pressure in the lungs (Pulmonary Hypertension)
- Thickening and enlargement of the left lower heart chamber (Left ventricular hypertrophy), which may lead to its malfunction (Left ventricular dysfunction)
Preventing Bronchopulmonary Dysplasia
Bronchopulmonary dysplasia (BPD) is a serious condition that impacts premature babies who need intensive care in a Neonatal Intensive Care Unit (NICU). This illness makes breathing difficult for the babies because their lungs are not fully formed and prepared to function properly. As a result, these babies often need to use a breathing tube and machine to support their breathing needs. They may also be given several medications during their hospital stay to assist with their lung condition. Some may need to continue using oxygen at home and if they get lung infections, they may need to go back to the hospital. Additionally, because BPD makes their bodies work harder, these babies might need extra nutrition.
Babies with BPD could also face additional challenges such as:
1. High blood pressure
2. Problems with their eyes and ears
3. Developmental delays
4. Heart issues.
While these babies are in the NICU, doctors need to stay alert for these potential complications. Even after the babies are discharged, they will likely need to be regularly checked by doctors and developmental specialists to monitor their progress.
