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| {{CMG}}; '''Associate Editor-in-Chief''': Piali Mukherjee | | {{CMG}}; '''Associate Editor-in-Chief''': Piali Mukherjee |
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| ==Overview== | | ==[[Bronchiectasis overview|Overview]]== |
| '''Bronchiectasis''' is a disease that causes localized, irreversible dilatation of part of the bronchial tree. 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 necrotizing bacterial infections, such as infections caused by the [[Staphylococcus]] or [[Klebsiella]] species or [[Bordetella pertussis]].<ref>{{cite encyclopedia| last = Hassan | first = Isaac | authorlink = | title = Bronchiectasis | encyclopedia = eMedicine Specialties Encyclopedia
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| | volume = | pages = | publisher = WebMD | location = Gibraltar | date = December 8, 2006 | url = http://www.emedicine.com/radio/topic116.htm}}</ref>
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| Rene Theophile Hyacinthe Laënnec, the man who invented the [[stethoscope]], used his creation to first discover bronchiectasis in 1819.<ref>{{cite journal |author=Roguin, A |title=Rene Theophile Hyacinthe Laënnec (1781–1826): The Man Behind the Stethoscope |language=English |journal=Clin Med Res|volume=4 |issue=3 |pages=230-35 |year=2006 |pmid= |doi=}}</ref>. The disease was researched in greater detail by Sir [[William Osler]] in the late 1800s; in fact, it is suspected that Osler actually died of complications from undiagnosed bronchiectasis<ref>{{cite journal |author=Wrong O |title=Osler and my father|language=English |journal=J R Soc Med |volume=96 |issue=6 |pages=462-64 |year=2003 |pmid= |doi=}}</ref>.
| | ==[[Bronchiectasis historical perspective|Historical Perspective]]== |
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| == Pathogenesis == | | ==[[Bronchiectasis pathophysiology|Pathophysiology]]== |
| Dilation of the bronchial walls results in airflow obstruction and impaired clearance of secretions because the dilated areas interrupt normal air pressure of the bronchial tubes, causing [[sputum]] to pool inside the dilated areas instead of being pushed upward<ref>{{cite journal |author=Morrissey BM |title=Pathogenesis of bronchiectasis |language=English |journal=Clin Chest Med|volume=28 |issue=2 |pages=289-96 |year=2007 |pmid=17467548 |doi=}}</ref>. The pooled sputum provides an environment conducive to the growth of infectious [[pathogen|pathogens]], and these areas of the lungs are thus very vulnerable to infection. The more infections that the lungs experience, the more damaged the lung tissue and [[alveoli]] become. When this happens, the bronchial tubes become more inelastic and dilated, which creates a perpetual, destructive cycle within this disease.
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| There are three types of brochiectasis, varying by level of severity. Fusiform (cylindrical) bronchiectasis (the most common type) refers to mildly inflamed bronchi that fail to taper distally. In varicose bronchiectasis, the bronchial walls appear beaded, because areas of dilation are mixed with areas of constriction. Saccular (cystic) bronchiectasis is characterized by severe, irreversible ballooning of the bronchi peripherally, with or without air-fluid levels.<ref>{{cite journal |author=Mysliwiec, V, Pina, JS |title=Bronchiectasis: the 'other' obstructive lung disease |language=English |journal=POSTGRADUATE MEDICINE |volume=106 |issue=1 |pages=252-63 |year=1999 |pmid= |doi=}}</ref> Chronic productive cough is prominent, occurring in up to 90% of patients with bronchiectasis. Sputum is produced on a daily basis in 76% of patients.<ref>{{cite encyclopedia| last = Emmons | first = Ethan | authorlink = | title = Bronchiectasis | encyclopedia = eMedicine Specialties Encyclopedia
| | ==[[Bronchiectasis epidemiology and demographics|Epidemiology and Demographics]]== |
| | volume = | pages = | publisher = WebMD | location = San Antonio, TX | date = January 31, 2007 | url = http://www.emedicine.com/med/topic246.htm}}</ref>
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| ==Causes== | | ==[[Bronchiectasis causes|Causes]]== |
| There are both [[congenital]] and acquired causes of bronchiectasis. [[Primary ciliary dyskinesia|Kartagener syndrome]], which affects the mobility of [[cilia]] in the lungs<ref>{{cite journal |author=Morillas HN, Zariwala M, Knowles MR|title=Genetic Causes of Bronchiectasis: Primary Ciliary Dyskinesia |language=English |journal=Respiration |volume=72 |issue=3 |pages=252-63 |year=2007 |pmid=17534128 |doi=}}</ref>, 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<ref>{{cite journal |author=Dalrymple-Hay MJ, Lucas J, Connett G, Lea RE|title=Lung resection for the treatment of severe localized bronchiectasis in cystic fibrosis patients.|language=English |journal=Acta Chir Hung. |volume=38 |issue=1 |pages=23-5 |year=1999 |pmid=10439089 |doi=}}</ref>. [[Young's syndrome]], which is clinically similar to Cystic Fibrosis, is thought to significantly contribute to the develop of Bronchiectasis. This is due to the occurrence of [[chronic]], sinopulmonary infections.<ref>{{cite journal |author=Handelsman DJ, Conway AJ, Boylan LM, & Turtle JR |title=Young's syndrome. Obstructive azoospermia and chronic sinopulmonary infections. |language=English |journal=NEJM |volume=310 |issue=1 |pages=3-9 |year=1984 |pmid= |doi=}}</ref> Patients with [[alpha 1-antitrypsin]] deficiency have been found to be particularly susceptible to bronchiectasis, for unknown reasons. <ref>{{cite journal |author=Shin MS, Ho KJ |title=Bronchiectasis in patients with alpha 1-antitrypsin deficiency. A rare occurrence?. |language=English |journal=Chest |volume=104 |issue= |pages=1384-86 |year=1993 |pmid= |doi=}}</ref> 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.<ref>{{cite journal |author=Notarangelo LD, Plebani A, Mazzolari E, Soresina A, Bondioni MP |title=Genetic causes of bronchiectasis: primary immune deficiencies and the lung |language=English |journal=Respiration |volume=74 |issue=3 |pages=264-75 |year=2007 |pmid=17534129 |doi=}}</ref>
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| Acquired bronchiectasis occurs more frequently, with one of the biggest causes being [[tuberculosis]]. Endobronchial tuberculosis
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| commonly leads to bronchiectasis, either from bronchial [[stenosis]] or secondary traction from fibrosis.<ref>{{cite encyclopedia| last = Catanzano | first = Tara | authorlink = | title = Primary Tuberculosis | encyclopedia = eMedicine Specialties Encyclopedia
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| | volume = | pages = | publisher = WebMD | location = Connecticut | date = September 5, 2005 | url = http://www.emedicine.com/radio/topic411.htm}}</ref> A especially common cause of the disease in children is [[AIDS|Acquired Immunodeficiency Syndrome]], stemming from [[HIV|the human immunodeficiency virus]]. This disease predisposes patients to a variety of pulmonary ailments, such as [[pneumonia]] and other opportunistic infections.<ref>{{cite journal |author=Sheikh S, Madiraju K, Steiner P, Rao M |title=Bronchiectasis in pediatric AIDS.|language=English |journal=Chest |volume=112 |issue=5 |pages=1202-7 |year=1997 |pmid=9367458 |doi=}}</ref>. 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.<ref>{{cite journal |author=Ferguson HR, Convery RP |title=An unusual complication of ulcerative colitis |language=English |journal=Postgrad. Med. J. |volume=78 |issue= |pages=503 |year=2002 |pmid= |doi=}}</ref> Recent evidence has shown an increased risk of Bronchiectasis in patients with [[Rheumatoid Arthritis|rheumatoid arthritis]] who smoke. One study stated a tenfold increased [[prevalence]] of the disease in this cohort<ref>{{cite journal |author=Kaushik, VV, Hutchinson D, Desmond J, Lynch MP, and Dawson JK |title=Association between bronchiectasis and smoking in patients with rheumatoid arthritis.|language=English |journal=Annals of the Rheumatic Diseases |volume=63|issue= |pages=1001-2 |year=2004 |pmid= |doi=}}</ref>. Still, it is unclear as to whether or not cigarette smoke is a specific primary cause of bronchiectasis.
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| Other acquired causes of bronchiectasis involving environmental exposures include respiratory infections, [[Airway_obstruction|obstructions]], inhalation and aspiration of [[ammonia]] and other toxic gases, [[pulmonary_aspiration|Pulmonary aspiration]], [[alcoholism]], [[heroin]] (drug use), and various [[allergy|allergies]].<ref>{{cite journal |author=Lamari NM, Martins ALQ, Oliveira JV, Marino LC, Valério N |title=Bronchiectasis and clearence physiotherapy: emphasis in postural drainage and percussion.|language=Portuguese |journal=Braz. j. cardiovasc. surg. |volume=21 |issue=2 |pages= |year=2006 |pmid= |doi=}}</ref>
| | ==[[Bronchiectasis differential diagnosis|Differentiating Bronchiectasis from other Disorders]]== |
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| | ==[[Bronchiectasis natural history|Natural History, Complications, and Prognosis]]== |
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| ==Diagnosis== | | ==Diagnosis== |
| The diagnosis of bronchiectasis is based on the review of clinical history and characteristic patterns in high-resolution [[Computed tomography|CT]] scan 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_%28tests%29|sensitivity]] of 80%, [[Specificity_%28tests%29|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 confirmation of an underlying problem via [[blood test|blood work]] and [[sputum]] culture samples.<ref>{{cite journal |author=Miller, JC |title=Pulmonary Mycobacterium Avium-Intracellular Infections in Women |language=English |journal=Radiology Rounds |volume=4 |issue=2 |pages= |year=2006 |pmid= |doi=}}</ref>
| | [[Bronchiectasis history and symptoms|History and Symptoms]] | [[Bronchiectasis physical examination|Physical Examination]] | [[Bronchiectasis laboratory tests|Laboratory Tests]] | [[Bronchiectasis electrocardiogram | Electrocardiogram]] | [[Bronchiectasis chest x ray|Chest X Ray]] | [[Bronchiectasis MRI|MRI]] | [[Bronchiectasis CT|CT]] | [[Bronchiectasis echocardiography|Echocardiography]] | [[Bronchiectasis other imaging findings|Other Imaging Findings]] | [[Bronchiectasis other diagnostic studies|Other Diagnostic Studies]] |
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| ==Treatment== | | ==Treatment== |
| Treatment of bronchiectasis is aimed at controlling [[infection]]s and bronchial secretions, relieving airway obstruction, and preventing [[Complication (medicine)|complication]]s. This includes prolonged usage of [[antibiotic|antibiotics]] to prevent detrimental infections<ref>{{cite journal |author=Evans DJ, Bara AI,Greenstone M |title=Prolonged antibiotics for purulent bronchiectasis in children and adults |language=English |journal=The Cochrane Database of Systematic Reviews |volume= |issue=2 |pages= |year=2007 |pmid= |doi=10.1002/14651858.CD001392.pub2}}</ref>, 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.<ref>{{cite journal |author=Ötgün B, Karnak B, Tanyel K, Enocak M, Büyükpamukçu N|title=Surgical treatment of bronchiectasis in children. |language=English |journal=Journal of Pediatric Surgery |volume=39 |issue=10 |pages=1532-36 |year=2003 |pmid= |doi=}}</ref>
| | '''Medical:''' [[Bronchiectasis medical therapy|Medical Therapy]] |
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| Inhaled [[steroid]] therapy that is consistently adhered to can reduce sputum production and decrease airway constriction over a period of time will prevent progression of bronchiectasis. One commonly used therapy is [[Beclometasone dipropionate]], also used in asthma treatment.<ref>{{cite journal |author=Elborn JS, Johnston B, Allen F, Clarke J, McGarry J, Varghese G. |title=Inhaled steroids in patients with bronchiectasis |language=English |journal=Respir Med |volume=86 |issue=2 |pages=121-4 |year=1992 |pmid=1615177 |doi=}}</ref> Use of inhalers such as [[Salbutamol|Albuterol (Salbutamol)]], [[Fluticasone|Fluticasone (Flovent/Flixotide)]] and [[Ipratropium|Ipratropium (Atrovent)]] may help reduce likelihood of infection by clearing the airways and decreasing inflammation.<ref>{{cite web | last = Reports | first = Consumer | authorlink = | coauthors = | title = Ipratropium and Albuterol Inhalation - Drug Review | work = | publisher = Consumer Reports of U.S.| url = http://www.consumerreports.org/mg/drug-reports/ipratropium-and-albuterol-inhalation.htm | format = | doi =}}</ref>
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| [[Mannitol]] dry inhalation powder, under the name Bronchitol, has been approved by the FDA for use in Cystic Fibrosis patients with Bronchiectasis. The original [[orphan drug]] indication approved in February 2005 allowed its use for the treatment of bronchiectasis. The original approval was based on the results of phase 2 clinical studies showing the product to be safe, well-tolerated, and effective for stimulating mucus hydration/clearance, thereby improving quality of life in patients with chronic obstructive lung diseases like Bronchiectasis. Long-term studies are currently underway to ensure the safety and effectiveness of the treatment, and it is not yet available on the market for use.<ref>{{cite web | last = Waknine | first = Yael | authorlink = | coauthors = | title = Orphan Drug Approvals: Bronchitol, Prestara, GTI-2040 | work = | publisher = Medscape today for WebMD | url = http://www.medscape.com/viewarticle/509116 | format = | doi =}}</ref>
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| ==Prevention==
| | '''Surgical:''' [[Bronchiectasis surgery|Surgery]] |
| In order to prevent future development of bronchiectasis, an x-ray of the chest should be taken after any severe attack of [[measles]], [[Pertussis|whooping cough]] or other acute respiratory infection in 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.<ref>{{cite journal |author=Crofton J|title=Diagnosis and Treatment of Bronchiectasis: II. Treatment and Prevention. |language=English |journal= Br Med J |volume=1 |issue=5490 |pages=783-785 |year=1966 |pmid= |doi=}}</ref>
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| A healthy [[BMI|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.<ref>{{cite journal |author=Onen ZP, Eris Gulbay B, Sen E, Akkoca Yildiz O, Saryal S, Acican T, Karabiyikoglu G|title=Analysis of the factors related to mortality in patients with bronchiectasis. |language=English |journal= Respir Med. |volume=101 |issue=7 |pages=1390-97 |year=2007 |pmid=17374480 |doi=}}</ref>
| | [[Bronchiectasis primary prevention|Primary Prevention]] | [[Bronchiectasis secondary prevention|Secondary Prevention]] | [[Bronchiectasis cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Bronchiectasis future or investigational therapies|Future or Investigational Therapies]] |
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| == References == | | == References == |