Bronchiectasis
- Date: 2007-04-23 - Word Count: 640
Share This!
Bronchiectasis is a chronic necrotizing infection of the bronchi and bronchioles leading to or associated with abnormal dilation of these airways. It is manifested clinically by cough, fever, and expectoration of copious amounts of foul-smelling, purulent sputum. To be considered bronchiectasis, the dilation should be permanent; reversible bronchial dilation often accompanies viral and bacterial pneumonia. Bronchiectasis has many origins and usually develops in association with the following conditions.
Bronchial obstruction, owing to tumor, foreign bodies, and occasionally mucous impaction, in which the bronchiectasis is localized to the obstructed lung segment, or owing to diffuse obsstructive airway disease, most commonly atopic asthma and chronic bronchitis.
Congenital or heriditary conditions, including congenital bronchiecasis (caused by a defect in the development of bronchi), cystic fibrosis, intalobar sequestration of the lung, immunodeficiency states, and immotile cilia and Kartagener syndromes.
Necrotizing pneumonia, most often caused by the tubercle bacillus or staphylococci or mixed infections.
Etiology and Pathogenesis
Obstruction and infection are the major influences associated with bronchiectasis, and it is likely that both are necessary for the development of full-fledged lesions. After bronchial obstruction, air is resorbed from the airways distal to the obstruction, with resultant atelectasis. Often accompanying atelectasis are early bronchial wall inflammation and the presence of intraluminal secretions that result in dilation of the walls of those airways that are present. These changes are reversible (1) if the obstruction persists, especially during periods of growth because the airways will not be able to develop normally and (2) if there is added infection. Infection plays a role in the pathogenesis of bronchiectasis in two ways: (1) It produces bronchial wall inflammation, with weakening and further dilation and (2) the extensive bronchial and bronchiolar damage causes endobronchial obliteration, with atelectasis, distal to the obliteration and subsequent bronchiectasis around atelectatic areas.
These mechanisms - infection and obstruction are most readily apparent in the severe form of bronchectasis associated with cystic fibrosis. In this disorder, there is squamous metaplasia of the normal respiratory epithelium with impairment of normal mucocilary action infection, necrosis of the bronchial and bronchiolar walls, and subsequent bronchiectasis. In younger children, the changes take the form of bronchiolitis (occlusion of the bronchioles by granulation tissue). But older children tend to develop full-blown bronchiectasis.
In Kartagener syndrome, charaterized by bronchiectasis, sinusitis and sutus inversus, there is a defect in ciliary motility associated with structural abnormalities of cila most commonly absent or irregular dynein arms the structures on the microtubular doublets of cilia that are responsible for the generation of ciliary movement. The lack of ciliary activity interferes with bacterial clearance, predisposes the sinuses and bronchi to infection and affects cell motility during embryogenesis, resulting in the situs inversus. Males with this condition tend to be infertile owing to ineffective mobility of the sperm tail. The syndrome is inherited as an autosomal recessive trait and is variable as about half the patients with defective filia have no situs inversus for uncertain reasons. In some groups of patients , the cilia are not immobile but have abnormal movement (ciliary dyskinesia). More may be involved in the genesis of this syndrome than ciliary abnormalities, since some abnormal cilia may be found in otherwise normal individuals or in patients with viral illnesses and bronchial inflammation.
Clinical Course
Bronchiectasis causes severe persistent cough; expectoration of foul smelling sometimes bloody squtum; and dyspnea and orthopnea in severe cases. A systemic febrile reaction may occur when powerful pathogens are present. These symptoms are often episodic and are precipitated by upper respiraatory tract infections or the introduction of new pathogenic agents. In the full-blown case, the cough is paroxysmal in nature. Such paroxysms are particularly frequent when the patient raises in the morning and the changes in position lead to drainage into the bronchi of the collected pools of pus. Obstructive ventilatory insufficiency can lead to marked dyspnea and cyanosis. Cor pulmonale metastatic brain abscesses, and amyloidosis are less frequent complications of bronchiectasis.
Bronchial obstruction, owing to tumor, foreign bodies, and occasionally mucous impaction, in which the bronchiectasis is localized to the obstructed lung segment, or owing to diffuse obsstructive airway disease, most commonly atopic asthma and chronic bronchitis.
Congenital or heriditary conditions, including congenital bronchiecasis (caused by a defect in the development of bronchi), cystic fibrosis, intalobar sequestration of the lung, immunodeficiency states, and immotile cilia and Kartagener syndromes.
Necrotizing pneumonia, most often caused by the tubercle bacillus or staphylococci or mixed infections.
Etiology and Pathogenesis
Obstruction and infection are the major influences associated with bronchiectasis, and it is likely that both are necessary for the development of full-fledged lesions. After bronchial obstruction, air is resorbed from the airways distal to the obstruction, with resultant atelectasis. Often accompanying atelectasis are early bronchial wall inflammation and the presence of intraluminal secretions that result in dilation of the walls of those airways that are present. These changes are reversible (1) if the obstruction persists, especially during periods of growth because the airways will not be able to develop normally and (2) if there is added infection. Infection plays a role in the pathogenesis of bronchiectasis in two ways: (1) It produces bronchial wall inflammation, with weakening and further dilation and (2) the extensive bronchial and bronchiolar damage causes endobronchial obliteration, with atelectasis, distal to the obliteration and subsequent bronchiectasis around atelectatic areas.
These mechanisms - infection and obstruction are most readily apparent in the severe form of bronchectasis associated with cystic fibrosis. In this disorder, there is squamous metaplasia of the normal respiratory epithelium with impairment of normal mucocilary action infection, necrosis of the bronchial and bronchiolar walls, and subsequent bronchiectasis. In younger children, the changes take the form of bronchiolitis (occlusion of the bronchioles by granulation tissue). But older children tend to develop full-blown bronchiectasis.
In Kartagener syndrome, charaterized by bronchiectasis, sinusitis and sutus inversus, there is a defect in ciliary motility associated with structural abnormalities of cila most commonly absent or irregular dynein arms the structures on the microtubular doublets of cilia that are responsible for the generation of ciliary movement. The lack of ciliary activity interferes with bacterial clearance, predisposes the sinuses and bronchi to infection and affects cell motility during embryogenesis, resulting in the situs inversus. Males with this condition tend to be infertile owing to ineffective mobility of the sperm tail. The syndrome is inherited as an autosomal recessive trait and is variable as about half the patients with defective filia have no situs inversus for uncertain reasons. In some groups of patients , the cilia are not immobile but have abnormal movement (ciliary dyskinesia). More may be involved in the genesis of this syndrome than ciliary abnormalities, since some abnormal cilia may be found in otherwise normal individuals or in patients with viral illnesses and bronchial inflammation.
Clinical Course
Bronchiectasis causes severe persistent cough; expectoration of foul smelling sometimes bloody squtum; and dyspnea and orthopnea in severe cases. A systemic febrile reaction may occur when powerful pathogens are present. These symptoms are often episodic and are precipitated by upper respiraatory tract infections or the introduction of new pathogenic agents. In the full-blown case, the cough is paroxysmal in nature. Such paroxysms are particularly frequent when the patient raises in the morning and the changes in position lead to drainage into the bronchi of the collected pools of pus. Obstructive ventilatory insufficiency can lead to marked dyspnea and cyanosis. Cor pulmonale metastatic brain abscesses, and amyloidosis are less frequent complications of bronchiectasis.
Related Tags: diabetes, depression, treatment, medical, disease, bronchiectasis
For more information about Bronchiectasis visit www.medicalhealthcenter.net Your Article Search Directory : Find in Articles
Recent articles in this category:
- How Safe Are Prescription Topical Non - Steroidal Drugs... Particularly in the Elderly?
The treatment of osteoarthritis, to date, is essentially palliative.Osteoarthritis is a degenerative - The Biggest Acne Myths Dispelled
Acne scars are sort of like being hit while you are down. First you live with the misery of the init - Natural Cure For Eczema - Become Eczema Free, The Natural Way!
When it comes to eczema, doctors' tend to have little advice to offer other than using creams and lo - Childhood Obesity Cured With Hypnosis
It is very unfortunate when a child is suffering from obesity. It is a very major medical problem th - Children Changing With Hypnosis
The challenges we face everyday in the world may cause difficulties in life for not only adults, but - Don't Suffer in Silence - Remove Your Warts and All
Many people suffer with skin conditions that can leave them worried, scared and feeling like they co - Treat Red and Irritated Skin Easily
Wash your skin with a gentle cleanser, apply a cold compress, soak in a warm oatmeal bath, apply Alo - How to Effectively Treat Stretch Marks to Diminish Them
Stretch marks or striae appear as red or purple marks on the skin and are actually a form of scarrin - Medicine: A Science and Art
Medicine is all about dealing with the healing human ailments. It is both a science as well as art a - Six Important Facts About Babesia
Babesia, which causes Babesiosis, generally requires two hosts throughout its lifespan. It originate
Most viewed articles in this category:
- Sinus Headache Relief
Sinus headache is a result of inflammation in the passage behind the cheeks, nose and eyes. It cause - Simple Lifestyle Changes That Can Help You Get Rid Of Acne
As anyone who has ever suffered knows, acne can be a debilitating condition, causing humiliation and - Acne Treatment For Children
Acne is a very common thing for children and adolescents especially between the ages of nine and sev - Coping With An Ileostomy Due To Crohns Disease
Crohn's sufferers that have constipation due to a stricture, have a severe case of Crohn's that may - Are There Home Remedies For Acid Reflux?
Acid Reflux or heart burn as it is commonly called is a very unpleasant condition in which the liqui - How To Relieve Sinus Pressure
Swollen, inflamed sinuses are, to put it mildly, very uncomfortable. Sinuses get infected and inflam - The Pain Of The Psoriasis Patient
Psoriasis is one of the most difficult diseases people have to deal with, effecting many areas in th - Lipitor Memory Loss: When Memories Vanish, What Can You Do?
Lipitor memory loss has been experienced by patients taking this statin medication to reduce cholest - Are Discount Vitamins For Everyone?
And the news is --- discount vitamins really are for just about everyone! Young, old, male, female, - Are Pharmaceutical Sales Reps Really Needed?
Aside from a few free samples, some cheap pens and calendars, or maybe a sweet magnet to put on your