Bronchiectasis
Encyclopedia
Bronchiectasis is a disease state defined by localized, irreversible dilation of part of the bronchial tree caused by destruction of the muscle and elastic tissue. It is classified as an obstructive lung disease
, along with emphysema
, bronchitis
, asthma
, and cystic fibrosis
. Involved bronchi are dilated, inflamed, and easily collapsible, resulting in airflow obstruction
and impaired clearance of secretions. Bronchiectasis is associated with a wide range of disorders, but it usually results from bacterial infections, such as infections caused by the Staphylococcus
or Klebsiella
species or Bordetella pertussis
.
findings. Such patterns include "tree-in-bud" abnormalities and cysts with definable borders. In one small study, CT findings of bronchiectasis and multiple small nodules were reported to have a sensitivity of 80%, specificity of 87%, and accuracy of 80% for the detection of bronchiectasis. Bronchiectasis may also be diagnosed without CT scan confirmation if clinical history clearly demonstrates frequent respiratory infections as well as confirmation of an underlying problem via blood work
and sputum
culture samples.
) is the leading cause of bronchiectasis, especially in children. AIDS predisposes patients to a variety of pulmonary ailments, such as pneumonia
and other opportunistic infections.
Tuberculosis
is another major cause. Endobronchial tuberculosis commonly leads to bronchiectasis, either from bronchial stenosis
or secondary traction
from fibrosis.
Bronchiectasis can sometimes be an unusual complication of inflammatory bowel disease
, especially ulcerative colitis
. It can occur in Crohn's disease
as well, but does so less frequently. Bronchiectasis in this situation usually stems from various allergic responses to inhaled fungus
spores.
Recent evidence has shown an increased risk of bronchiectasis in patients with rheumatoid arthritis
who smoke. One study stated a tenfold increased prevalence
of the disease in this cohort. Still, it is unclear as to whether or not cigarette smoke is a specific primary cause of bronchiectasis.
Other acquired causes of bronchiectasis involving environmental exposures include respiratory infections, obstructions
, inhalation and aspiration of ammonia
and other toxic gases, pulmonary aspiration
, alcoholism
, heroin (drug use), various allergies
, and allergic bronchopulmonary aspergillosis
.
, which affects the mobility of cilia in the lungs, aids in the development of the disease. Another common genetic cause is cystic fibrosis
, in which a small number of patients develop severe localized bronchiectasis. Young's syndrome, which is clinically similar to cystic fibrosis, is thought to significantly contribute to the development of bronchiectasis. This is due to the occurrence of chronic
, sinopulmonary infections. Patients with alpha 1-antitrypsin
deficiency have been found to be particularly susceptible to bronchiectasis, for unknown reasons. Other less-common congenital causes include primary immunodeficiencies, due to the weakened or nonexistent immune system response to severe, recurrent infections that commonly affect the lung. Several other congenital disorders can also lead to bronchiectasis, including Williams-Campbell syndrome
and Marfan syndrome
.
and other acute respiratory infections of childhood. While smoking
has not been found to be a direct cause of bronchiectasis, it is certainly an irritant that all patients should avoid in order to prevent the development of infections (such as bronchitis
) and further complications.
A healthy body mass index
, vaccination
(especially against pneumonia and influenza
) and regular doctor visits may have beneficial effects on the prevention of progressing bronchiectasis. The presence of hypoxemia
, hypercapnia
, dyspnea
level and radiographic extent can greatly affect the mortality rate from this disease.
s and bronchial secretions, relieving airway obstructions, removal of affected portions of lung by surgical removal or artery embolization and preventing complication
s. This includes the prolonged usage of antibiotic
s to prevent detrimental infections, as well as eliminating accumulated fluid with postural drainage
and chest physiotherapy. Surgery may also be used to treat localized bronchiectasis, removing obstructions that could cause progression of the disease.
Inhaled steroid
therapy that is consistently adhered to can reduce sputum production and decrease airway constriction over a period of time, and help prevent progression of bronchiectasis. One commonly used therapy is beclometasone dipropionate
, which is also used in asthma
treatment. Use of inhalers such as albuterol (salbutamol)
, fluticasone (Flovent/Flixotide)
and ipratropium (Atrovent)
may help reduce likelihood of infection by clearing the airways and decreasing inflammation.
Although not approved for use in any country, Mannitol
dry inhalation powder, under the name Bronchitol, has been granted orphan drug
status by the FDA
for use in patients with bronchiectasis and with cystic fibrosis.
Combination therapies, long acting bronchodilators and inhaled corticosteroids such as Symbicort and Advair Diskus are also commonly used inhaled medicines which has in many cases been effective in clearing the airways, reducing sputum and reducing inflammation.
, the man who invented the stethoscope
, used his invention to first discover bronchiectasis in 1819. The disease was researched in greater detail by Sir William Osler
in the late 1800s; it is suspected that Osler actually died of complications from undiagnosed bronchiectasis.
Obstructive lung disease
Obstructive lung disease is a category of respiratory disease characterized by airway obstruction. It is generally characterized by inflamed and easily collapsible airways, obstruction to airflow, and frequent office visits and hospitalizations. Types of obstructive lung disease include; Asthma,...
, along with emphysema
Emphysema
Emphysema is a long-term, progressive disease of the lungs that primarily causes shortness of breath. In people with emphysema, the tissues necessary to support the physical shape and function of the lungs are destroyed. It is included in a group of diseases called chronic obstructive pulmonary...
, bronchitis
Bronchitis
Acute bronchitis is an inflammation of the large bronchi in the lungs that is usually caused by viruses or bacteria and may last several days or weeks. Characteristic symptoms include cough, sputum production, and shortness of breath and wheezing related to the obstruction of the inflamed airways...
, asthma
Asthma
Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...
, and cystic fibrosis
Cystic fibrosis
Cystic fibrosis is a recessive genetic disease affecting most critically the lungs, and also the pancreas, liver, and intestine...
. Involved bronchi are dilated, inflamed, and easily collapsible, resulting in airflow obstruction
Airway obstruction
Airway obstruction is a respiratory problem caused by increased resistance in the bronchioles that reduces the amount of air inhaled in each breath and the oxygen that reaches the pulmonary arteries...
and impaired clearance of secretions. Bronchiectasis is associated with a wide range of disorders, but it usually results from bacterial infections, such as infections caused by the Staphylococcus
Staphylococcus
Staphylococcus is a genus of Gram-positive bacteria. Under the microscope they appear round , and form in grape-like clusters....
or Klebsiella
Klebsiella
Klebsiella is a genus of non-motile, Gram-negative, oxidase-negative, rod-shaped bacteria with a prominent polysaccharide-based capsule. It is named after the German microbiologist Edwin Klebs...
species or Bordetella pertussis
Bordetella pertussis
Bordetella pertussis is a Gram-negative, aerobic coccobacillus of the genus Bordetella, and the causative agent of pertussis or whooping cough. Unlike B. bronchiseptica, B. pertussis is non-motile. Its virulence factors include pertussis toxin, filamentous hæmagglutinin, pertactin, fimbria, and...
.
Signs and symptoms
People with bronchiectasis produce frequent green/yellow sputum (patients with bronchiectasis may produce 240ml (8 oz) of sputum daily). They may have bad breath and, when associated with cystic fibrosis, diarrhea (patients with cystic fibrosis often develop chronic pancreatitis).Diagnosis
The diagnosis of bronchiectasis is based on the review of clinical history and characteristic patterns in high-resolution CT scanComputed tomography
X-ray computed tomography or Computer tomography , is a medical imaging method employing tomography created by computer processing...
findings. Such patterns include "tree-in-bud" abnormalities and cysts with definable borders. In one small study, CT findings of bronchiectasis and multiple small nodules were reported to have a sensitivity of 80%, specificity of 87%, and accuracy of 80% for the detection of bronchiectasis. Bronchiectasis may also be diagnosed without CT scan confirmation if clinical history clearly demonstrates frequent respiratory infections as well as confirmation of an underlying problem via blood work
Blood test
A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a needle, or via fingerprick....
and sputum
Sputum
Sputum is mucus that is coughed up from the lower airways. It is usually used for microbiological investigations of respiratory infections....
culture samples.
Causes
Bronchiectasis has both congenital and acquired causes, with the latter more frequent.Acquired causes
Acquired Immune Deficiency Syndrome (AIDSAIDS
Acquired immune deficiency syndrome or acquired immunodeficiency syndrome is a disease of the human immune system caused by the human immunodeficiency virus...
) is the leading cause of bronchiectasis, especially in children. AIDS predisposes patients to a variety of pulmonary ailments, such as pneumonia
Pneumonia
Pneumonia is an inflammatory condition of the lung—especially affecting the microscopic air sacs —associated with fever, chest symptoms, and a lack of air space on a chest X-ray. Pneumonia is typically caused by an infection but there are a number of other causes...
and other opportunistic infections.
Tuberculosis
Tuberculosis
Tuberculosis, MTB, or TB is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis usually attacks the lungs but can also affect other parts of the body...
is another major cause. Endobronchial tuberculosis commonly leads to bronchiectasis, either from bronchial stenosis
Stenosis
A stenosis is an abnormal narrowing in a blood vessel or other tubular organ or structure.It is also sometimes called a stricture ....
or secondary traction
Traction bronchiectasis
In medicine, traction bronchiectasis is a finding of abnormal airway dilation due to lung fibrosis. It is typically seen on high resolution computed tomography scan.It is classically seen in idiopathic pulmonary fibrosis.-External links:**...
from fibrosis.
Bronchiectasis can sometimes be an unusual complication of inflammatory bowel disease
Inflammatory bowel disease
In medicine, inflammatory bowel disease is a group of inflammatory conditions of the colon and small intestine. The major types of IBD are Crohn's disease and ulcerative colitis.-Classification:...
, especially ulcerative colitis
Ulcerative colitis
Ulcerative colitis is a form of inflammatory bowel disease . Ulcerative colitis is a form of colitis, a disease of the colon , that includes characteristic ulcers, or open sores. The main symptom of active disease is usually constant diarrhea mixed with blood, of gradual onset...
. It can occur in Crohn's disease
Crohn's disease
Crohn's disease, also known as regional enteritis, is a type of inflammatory bowel disease that may affect any part of the gastrointestinal tract from mouth to anus, causing a wide variety of symptoms...
as well, but does so less frequently. Bronchiectasis in this situation usually stems from various allergic responses to inhaled fungus
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
spores.
Recent evidence has shown an increased risk of bronchiectasis in patients with rheumatoid arthritis
Rheumatoid arthritis
Rheumatoid arthritis is a chronic, systemic inflammatory disorder that may affect many tissues and organs, but principally attacks synovial joints. The process produces an inflammatory response of the synovium secondary to hyperplasia of synovial cells, excess synovial fluid, and the development...
who smoke. One study stated a tenfold increased prevalence
Prevalence
In epidemiology, the prevalence of a health-related state in a statistical population is defined as the total number of cases of the risk factor in the population at a given time, or the total number of cases in the population, divided by the number of individuals in the population...
of the disease in this cohort. Still, it is unclear as to whether or not cigarette smoke is a specific primary cause of bronchiectasis.
Other acquired causes of bronchiectasis involving environmental exposures include respiratory infections, obstructions
Airway obstruction
Airway obstruction is a respiratory problem caused by increased resistance in the bronchioles that reduces the amount of air inhaled in each breath and the oxygen that reaches the pulmonary arteries...
, inhalation and aspiration of ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...
and other toxic gases, pulmonary aspiration
Pulmonary aspiration
Pulmonary aspiration is the entry of material from the oropharynx or gastrointestinal tract into the larynx and lower respiratory tract...
, alcoholism
Alcoholism
Alcoholism is a broad term for problems with alcohol, and is generally used to mean compulsive and uncontrolled consumption of alcoholic beverages, usually to the detriment of the drinker's health, personal relationships, and social standing...
, heroin (drug use), various allergies
Allergy
An Allergy is a hypersensitivity disorder of the immune system. Allergic reactions occur when a person's immune system reacts to normally harmless substances in the environment. A substance that causes a reaction is called an allergen. These reactions are acquired, predictable, and rapid...
, and allergic bronchopulmonary aspergillosis
Allergic bronchopulmonary aspergillosis
In medicine, allergic bronchopulmonary aspergillosis is a condition characterised by an exaggerated response of the immune system to the fungus Aspergillus . It occurs most often in patients with asthma or cystic fibrosis...
.
Congenital causes
Kartagener syndromePrimary ciliary dyskinesia
Primary ciliary dyskinesia , also known as immotile ciliary syndrome or Kartagener Syndrome ', is a rare, ciliopathic, autosomal recessive genetic disorder that causes a defect in the action of the cilia lining the respiratory tract and fallopian tube, and also of the flagella of sperm in...
, which affects the mobility of cilia in the lungs, aids in the development of the disease. Another common genetic cause is cystic fibrosis
Cystic fibrosis
Cystic fibrosis is a recessive genetic disease affecting most critically the lungs, and also the pancreas, liver, and intestine...
, in which a small number of patients develop severe localized bronchiectasis. Young's syndrome, which is clinically similar to cystic fibrosis, is thought to significantly contribute to the development of bronchiectasis. This is due to the occurrence of chronic
Chronic (medicine)
A chronic disease is a disease or other human health condition that is persistent or long-lasting in nature. The term chronic is usually applied when the course of the disease lasts for more than three months. Common chronic diseases include asthma, cancer, diabetes and HIV/AIDS.In medicine, the...
, sinopulmonary infections. Patients with alpha 1-antitrypsin
Alpha 1-antitrypsin
Alpha 1-Antitrypsin or α1-antitrypsin is a protease inhibitor belonging to the serpin superfamily. It is generally known as serum trypsin inhibitor. Alpha 1-antitrypsin is also referred to as alpha-1 proteinase inhibitor because it inhibits a wide variety of proteases...
deficiency have been found to be particularly susceptible to bronchiectasis, for unknown reasons. Other less-common congenital causes include primary immunodeficiencies, due to the weakened or nonexistent immune system response to severe, recurrent infections that commonly affect the lung. Several other congenital disorders can also lead to bronchiectasis, including Williams-Campbell syndrome
Williams-Campbell syndrome
Williams-Campbell syndrome is a disease of the airways where cartilage in the bronchi is defective. This leads to collapse of the airways and bronchiectasis.Williams-Campbell syndrome is deficiency of the bronchial cartilage distally.Symptoms:...
and Marfan syndrome
Marfan syndrome
Marfan syndrome is a genetic disorder of the connective tissue. People with Marfan's tend to be unusually tall, with long limbs and long, thin fingers....
.
Prevention
In order to prevent bronchiectasis, children should be immunized against measles, pertussisPertussis
Pertussis, also known as whooping cough , is a highly contagious bacterial disease caused by Bordetella pertussis. Symptoms are initially mild, and then develop into severe coughing fits, which produce the namesake high-pitched "whoop" sound in infected babies and children when they inhale air...
and other acute respiratory infections of childhood. While smoking
Tobacco smoking
Tobacco smoking is the practice where tobacco is burned and the resulting smoke is inhaled. The practice may have begun as early as 5000–3000 BCE. Tobacco was introduced to Eurasia in the late 16th century where it followed common trade routes...
has not been found to be a direct cause of bronchiectasis, it is certainly an irritant that all patients should avoid in order to prevent the development of infections (such as bronchitis
Bronchitis
Acute bronchitis is an inflammation of the large bronchi in the lungs that is usually caused by viruses or bacteria and may last several days or weeks. Characteristic symptoms include cough, sputum production, and shortness of breath and wheezing related to the obstruction of the inflamed airways...
) and further complications.
A healthy body mass index
Body mass index
The body mass index , or Quetelet index, is a heuristic proxy for human body fat based on an individual's weight and height. BMI does not actually measure the percentage of body fat. It was invented between 1830 and 1850 by the Belgian polymath Adolphe Quetelet during the course of developing...
, vaccination
Vaccination
Vaccination is the administration of antigenic material to stimulate the immune system of an individual to develop adaptive immunity to a disease. Vaccines can prevent or ameliorate the effects of infection by many pathogens...
(especially against pneumonia and influenza
Influenza
Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae , that affects birds and mammals...
) and regular doctor visits may have beneficial effects on the prevention of progressing bronchiectasis. The presence of hypoxemia
Hypoxemia
Hypoxemia is generally defined as decreased partial pressure of oxygen in blood, sometimes specifically as less than or causing hemoglobin oxygen saturation of less than 90%.-Distinction from anemia and hypoxia:...
, hypercapnia
Hypercapnia
Hypercapnia or hypercapnea , also known as hypercarbia, is a condition where there is too much carbon dioxide in the blood...
, dyspnea
Dyspnea
Dyspnea , shortness of breath , or air hunger, is the subjective symptom of breathlessness.It is a normal symptom of heavy exertion but becomes pathological if it occurs in unexpected situations...
level and radiographic extent can greatly affect the mortality rate from this disease.
Treatment
Treatment of bronchiectasis includes controlling infectionInfection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
s and bronchial secretions, relieving airway obstructions, removal of affected portions of lung by surgical removal or artery embolization and preventing complication
Complication (medicine)
Complication, in medicine, is an unfavorable evolution of a disease, a health condition or a medical treatment. The disease can become worse in its severity or show a higher number of signs, symptoms or new pathological changes, become widespread throughout the body or affect other organ systems. A...
s. This includes the prolonged usage of antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
s to prevent detrimental infections, as well as eliminating accumulated fluid with postural drainage
Postural drainage
Drainage used in bronchiectasis and lung abscess. The patient's body is positioned so that the trachea is inclined downward and below the affected chest area . Postural drainage is essential in treating bronchiectasis and patients must receive physiotherapy to learn to tip themselves into a...
and chest physiotherapy. Surgery may also be used to treat localized bronchiectasis, removing obstructions that could cause progression of the disease.
Inhaled steroid
Steroid
A steroid is a type of organic compound that contains a characteristic arrangement of four cycloalkane rings that are joined to each other. Examples of steroids include the dietary fat cholesterol, the sex hormones estradiol and testosterone, and the anti-inflammatory drug dexamethasone.The core...
therapy that is consistently adhered to can reduce sputum production and decrease airway constriction over a period of time, and help prevent progression of bronchiectasis. One commonly used therapy is beclometasone dipropionate
Beclometasone dipropionate
Beclometasone dipropionate or beclomethasone dipropionate , also referred to as beclometasone , is a potent glucocorticoid steroid. In the form of an inhaler , a wide number of brands of which are available, it is used for the prophylaxis of asthma. As a nasal spray Beclometasone dipropionate (INN...
, which is also used in asthma
Asthma
Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...
treatment. Use of inhalers such as albuterol (salbutamol)
Salbutamol
Salbutamol or albuterol is a short-acting β2-adrenergic receptor agonist used for the relief of bronchospasm in conditions such as asthma and chronic obstructive pulmonary disease. It is marketed as Ventolin among other brand names....
, fluticasone (Flovent/Flixotide)
Fluticasone
Fluticasone is a synthetic glucocorticoid.Both the furoate and propionate forms are used as topical anti-inflammatories:*Fluticasone propionate*Fluticasone furoateTreatment of asthma - Fluticasone in combination with Salmeterol - "[]" - aerosol....
and ipratropium (Atrovent)
Ipratropium
Ipratropium bromide is an anticholinergic drug used for the treatment of chronic obstructive pulmonary disease and acute asthma. It blocks the muscarinic acetylcholine receptors in the smooth muscles of the bronchi in the lungs, opening the bronchi...
may help reduce likelihood of infection by clearing the airways and decreasing inflammation.
Although not approved for use in any country, Mannitol
Mannitol
Mannitol is a white, crystalline organic compound with the formula . This polyol is used as an osmotic diuretic agent and a weak renal vasodilator...
dry inhalation powder, under the name Bronchitol, has been granted orphan drug
Orphan drug
An orphan drug is a pharmaceutical agent that has been developed specifically to treat a rare medical condition, the condition itself being referred to as an orphan disease...
status by the FDA
Food and Drug Administration
The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...
for use in patients with bronchiectasis and with cystic fibrosis.
Combination therapies, long acting bronchodilators and inhaled corticosteroids such as Symbicort and Advair Diskus are also commonly used inhaled medicines which has in many cases been effective in clearing the airways, reducing sputum and reducing inflammation.
History
Rene LaënnecRené Laennec
René-Théophile-Hyacinthe Laennec was a French physician. He invented the stethoscope in 1816, while working at the Hôpital Necker and pioneered its use in diagnosing various chest conditions....
, the man who invented the stethoscope
Stethoscope
The stethoscope is an acoustic medical device for auscultation, or listening to the internal sounds of an animal body. It is often used to listen to lung and heart sounds. It is also used to listen to intestines and blood flow in arteries and veins...
, used his invention to first discover bronchiectasis in 1819. The disease was researched in greater detail by Sir William Osler
William Osler
Sir William Osler, 1st Baronet was a physician. He was one of the "Big Four" founding professors at Johns Hopkins Hospital as the first Professor of Medicine and founder of the Medical Service there. Sir William Osler, 1st Baronet (July 12, 1849 – December 29, 1919) was a physician. He was...
in the late 1800s; it is suspected that Osler actually died of complications from undiagnosed bronchiectasis.