It has been defined as "persistent irreversible dilatation and distortion of medium-sized bronchi."
In the past, changes related to bronchiectasis tended to develop during childhood, but improved hygiene standards, antibiotics, and immunization programs have made childhood infections less common, and bronchiectasis now affects people who are middle-aged and older.
In industrialized countries, bronchiectasis normally stems from an underlying medical condition that damages the airway walls or prevents them from removing mucus, such as cystic fibrosis or primary ciliary dyskinesia.
Bronchiectasis is serious. There is no cure, and complications can be fatal if it is left untreated. However, early diagnosis and treatment can prevent it from worsening.
Signs and symptoms of bronchiectasis
Bronchiectasis can cause a person to feel that they are short of breath.
Bronchiectasis is normally an acquired condition. It happens because of damage to the airways. The signs and symptoms may not appear for months, and sometimes not for years.
The most common signs and symptoms include a cough that continues daily for months or years. The cough may worsen when lying on one side.
Excessive sputum will be coughed up and spat out. The sputum may be foul-smelling and it may contain mucus, trapped particles, and pus.
The person is likely to experience wheezing and shortness of breath, and the lungs will crackle when heard through a stethoscope.
The flesh under the fingernails and toenails may become thicker, and nails may curve downward.
Later signs and symptoms may include:
- Paleness or a bluish skin color
- Weight loss
- Slow growth in children
- Coughing up of blood or bloody mucus
- Breath odor.
Patients with severe bronchiectasis may eventually develop more serious conditions, such as a collapsed lung, respiratory failure, and eventually heart failure.
Causes of bronchiectasis
In the human respiratory system, air enters and leaves the lungs through a series of branching airways called bronchial tubes. Normally, the bronchial tubes narrow smoothly towards the edges of each lung.
In bronchiectasis, the cilla in he bronchial tubes do not sweep mucus upwards.
In bronchiectasis the airways are damaged, and they widen instead of narrow. This is called bronchiectasia.
The linings of the bronchial tubes are covered in cilia and mucus. Mucus protects against undesirable particles that get into the lungs. Cilia are hair-like structures which sweep the particles and excess mucus upwards, out of the lung.
Usually a person does not notice the mucus coming out, unless an excess volume of mucus is pushed up, in which case the person will cough.
In bronchiectasis, the cilia in the bronchial tubes are destroyed or immobilized, so the particles and mucus are not swept upwards. Instead, they accumulate, as do bacteria. The sputum, or phlegm, can become sticky and difficult to move, even with coughing.
The accumulated sputum is an ideal environment for bacteria to multiply and cause infection, further damaging the bronchial tubes. As more sputum builds up, there is more bacteria, more infection, more damage and further sputum build up.
Conditions that increase the risk of bronchiectasis
The exact cause of bronchiectasis is unclear, but damage to the bronchial tubes may stem from tuberculosis (TB), pneumonia, a fungal infection, or whooping cough early in life. Measles can also damage the lungs.
A persistent cough is a sign of bronchiectasis.
Other conditions that increase the risk include:
- Cystic fibrosis, a chronic disease in which damage to the body's organs causes mucus to become thick and sticky. This mucus can clog the airways, leading to infections and lung damage.
- Young's syndrome, in which a person's mucus is abnormally viscous, in addition to other issues.
- Allergic bronchopulmonary aspergillosis (ABPA) is an allergy to aspergillus, a type of fungus. This can lead to inflammation of the airways and the air sacs of the lungs. Untreated, it can result in bronchiectasis.
- Primary ciliary dyskinesia (PCD), or Kartagener Syndrome (KS), is an inherited condition in which the cilia in the respiratory tract function poorly and cannot effectively sweep out secretions. This can lead to recurrent infections.
If bronchiectasis affects only one part of the lung, this may indicate an airway blockage, possibly due to a noncancerous growth or an inhaled object, such as a peanut.
Inhaling ammonia and other toxic gases or liquids may also lead to bronchiectasis.
Treatment of bronchiectasis
Bronchiectasis is incurable, but early and effective treatment can help to reduce complications, control infections and secretions, and to relieve obstructions in the airway.
In severe cases, oxygen therapy may be necessary.
Infections can be treated with antibiotics, bronchodilators and physical therapy, to promote secretion drainage. Long-term antibiotic use can prevent infection recurrence, especially in cases of cystic fibrosis.
Bronchodilators relax the muscles and open the airways. They are usually breathed in as a fine mist using an inhaler or nebulizer. Inhalation takes the medicine straight into the lungs, for rapid effect.
Keeping hydrated reduces the chance of the mucus becoming thick and sticky.
Patients with widespread bronchiectasis resulting in respiratory failure may receive oxygen therapy if blood oxygen levels are low.
Treating inflammation and mucus accumulation
Inhaled corticosteroids can treat inflammation. Used consistently, they can significantly reduce sputum production and airway constriction. This helps to stop the condition from getting worse.
Patients who are wheezing or short of breath may benefit from oral and inhaled corticosteroids, either alone or with bronchodilators.
Mucolytics and saline may be used to thin the pus and mucus. However, the effectiveness of mucolytics in bronchiectasis has been questioned. Anti-cough medicine is not recommended, because coughing can help to remove mucus.
Postural drainage and chest percussion can help to drain the mucus.
In postural drainage, positioning the patient at certain postures and angles uses gravity to clear congestion.
Chest percussion, also known as chest physical therapy (CPT) or chest clapping, involves tapping the chest with hollowed hands or a percussion device to loosen the mucus so that the patient can cough it up.
An electric chest clapper or an inflatable therapy vest that uses high-frequency air waves can achieve similar effects. Another small, handheld device called an Acapella causes vibrations that help loosen the mucus when the patient breathes through it.
Exercises to strengthen the chest muscles can help a patient breathe more easily, according to the BMJ best practice.
Removing a bronchial obstruction
In the case of bronchial obstruction, bronchoscopy is used to remove the blockage before severe damage occurs. This may be a small item lodged in the airway.
A bronchoscope is a long, thin, flexible tube with a light and camera at the end that goes into the airway via the mouth or nose. The doctor can see the inside of the airway on a monitor.
Lung surgery and embolization
In rare cases, surgery may be needed to remove part of a lung. This is only an option if a single lung is affected, and normally involves only one lung lobe or segment.
Other patients who may need surgery are those who have recurrent infections, despite treatment, and those who cough up large amounts of blood.
Embolization can be used instead of surgery to stop bleeding in patients who cough up a lot of blood. A catheter is used to inject a substance that clots the bleeding vessel.
Lung transplantation may be recommended for patients with advanced bronchiectasis and also cystic fibrosis.
Complications and outlook for bronchiectasis
Complications of bronchiectasis include repeat infections, low blood oxygen levels, respiratory failure, spitting up blood or bloody sputum, and cor pulmonale, a heart disease caused by very high resistance to the passage of blood through the lungs.
The prognosis depends on several factors, but mainly on how well infections and possible complications are controlled or prevented.
Delayed treatment, and co-existing conditions such as chronic bronchitis or emphysema, can worsen the prognosis. Complications, such as pulmonary hypertension and cor pulmonale increase the risk of a poor outcome.
Early treatment is important, to reduce the risks.