Chronic bronchitis
Encyclopedia
Chronic bronchitis is a chronic
inflammation
of the bronchi
(medium-size airways) in the lung
s. It is generally considered one of the two forms of chronic obstructive pulmonary disease
(COPD). It is defined clinically as a persistent cough
that produces sputum
(phlegm) and mucus, for at least three months per year in two consecutive years.
(also known as a productive cough, i.e. one that produces sputum
), shortness of breath (dyspnea
) and wheezing. Occasionally chest pain
s, fever
, and fatigue
or malaise
may also occur. Mucus is often green or yellowish green and also may be orange or pink, depending on the pathogen causing the inflammation.
is the most common cause. Pneumoconiosis
and long-term fume inhalation are other causes. Allergies can also cause mucus hypersecretion, thus leading to symptoms similar to asthma or bronchitis.
will often reveal diminished breath sounds, wheezing and prolonged expiration
. Most doctors rely on the presence of a persistent dry or wet cough as evidence of bronchitis.
A variety of tests may be performed in patients presenting with cough and shortness of breath:
or doxycycline
is recommended.
is an example of a bronchodilator that may be useful for people suffering from chronic obstructive pulmonary disease, such as chronic bronchitis.
Albuterol is also a common drug for this disease.
During AECB, breathing becomes much more difficult because of further narrowing of the airways, in addition to increased secretion of mucus, which often is thicker than usual.
Treatment of AECB may include:
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...
inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
of the bronchi
Bronchus
A bronchus is a passage of airway in the respiratory tract that conducts air into the lungs. The bronchus branches into smaller tubes, which in turn become bronchioles....
(medium-size airways) in the lung
Lung
The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
s. It is generally considered one of the two forms of chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease , also known as chronic obstructive lung disease , chronic obstructive airway disease , chronic airflow limitation and chronic obstructive respiratory disease , is the co-occurrence of chronic bronchitis and emphysema, a pair of commonly co-existing diseases...
(COPD). It is defined clinically as a persistent cough
Cough
A cough is a sudden and often repetitively occurring reflex which helps to clear the large breathing passages from secretions, irritants, foreign particles and microbes...
that produces sputum
Sputum
Sputum is mucus that is coughed up from the lower airways. It is usually used for microbiological investigations of respiratory infections....
(phlegm) and mucus, for at least three months per year in two consecutive years.
Signs and symptoms
Bronchitis may be indicated by an expectorating coughCough
A cough is a sudden and often repetitively occurring reflex which helps to clear the large breathing passages from secretions, irritants, foreign particles and microbes...
(also known as a productive cough, i.e. one that produces sputum
Sputum
Sputum is mucus that is coughed up from the lower airways. It is usually used for microbiological investigations of respiratory infections....
), shortness of breath (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...
) and wheezing. Occasionally chest pain
Chest pain
Chest pain may be a symptom of a number of serious conditions and is generally considered a medical emergency. Even though it may be determined that the pain is non-cardiac in origin, this is often a diagnosis of exclusion made after ruling out more serious causes of the pain.-Differential...
s, fever
Fever
Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...
, and fatigue
Fatigue (physical)
Fatigue is a state of awareness describing a range of afflictions, usually associated with physical and/or mental weakness, though varying from a general state of lethargy to a specific work-induced burning sensation within one's muscles...
or malaise
Malaise
Malaise is a feeling of general discomfort or uneasiness, of being "out of sorts", often the first indication of an infection or other disease. Malaise is often defined in medicinal research as a "general feeling of being unwell"...
may also occur. Mucus is often green or yellowish green and also may be orange or pink, depending on the pathogen causing the inflammation.
Causes
Tobacco smokingTobacco 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...
is the most common cause. Pneumoconiosis
Pneumoconiosis
Pneumoconiosis is an occupational lung disease and a restrictive lung disease caused by the inhalation of dust, often in mines.-Types:Depending upon the type of dust, the disease is given different names:...
and long-term fume inhalation are other causes. Allergies can also cause mucus hypersecretion, thus leading to symptoms similar to asthma or bronchitis.
Diagnosis
A physical examinationPhysical examination
Physical examination or clinical examination is the process by which a doctor investigates the body of a patient for signs of disease. It generally follows the taking of the medical history — an account of the symptoms as experienced by the patient...
will often reveal diminished breath sounds, wheezing and prolonged expiration
Exhalation
Exhalation is the movement of air out of the bronchial tubes, through the airways, to the external environment during breathing....
. Most doctors rely on the presence of a persistent dry or wet cough as evidence of bronchitis.
A variety of tests may be performed in patients presenting with cough and shortness of breath:
- Pulmonary Function Tests (PFT) (or spirometrySpirometrySpirometry is the most common of the pulmonary function tests , measuring lung function, specifically the measurement of the amount and/or speed of air that can be inhaled and exhaled...
) must be performed in all patients presenting with chronic cough. An FEV1/FVC ratio below 0.7 that is not fully reversible after bronchodilator therapy indicates the presence of COPDChronic obstructive pulmonary diseaseChronic obstructive pulmonary disease , also known as chronic obstructive lung disease , chronic obstructive airway disease , chronic airflow limitation and chronic obstructive respiratory disease , is the co-occurrence of chronic bronchitis and emphysema, a pair of commonly co-existing diseases...
, that requires more aggressive therapy and carries a more severe prognosis than simple chronic bronchitis. - A chest X-rayChest X-rayIn medicine, a chest radiograph, commonly called a chest X-ray , is a projection radiograph of the chest used to diagnose conditions affecting the chest, its contents, and nearby structures...
that reveals hyperinflation; collapse and consolidation of lung areas would support a diagnosis of pneumoniaPneumoniaPneumonia 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...
. Some conditions that predispose to bronchitis may be indicated by chest radiography. - A sputum sample showing neutrophil granulocyteNeutrophil granulocyteNeutrophil granulocytes are the most abundant type of white blood cells in mammals and form an essential part of the innate immune system. They are generally referred to as either neutrophils or polymorphonuclear neutrophils , and are subdivided into segmented neutrophils and banded neutrophils...
s (inflammatory white blood cells) and cultureMicrobiological cultureA microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture media under controlled laboratory conditions. Microbial cultures are used to determine the type of organism, its abundance in the sample being tested,...
showing that has pathogenic microorganisms such as Streptococcus spp.StreptococcusStreptococcus is a genus of spherical Gram-positive bacteria belonging to the phylum Firmicutes and the lactic acid bacteria group. Cellular division occurs along a single axis in these bacteria, and thus they grow in chains or pairs, hence the name — from Greek στρεπτος streptos, meaning... - A blood testBlood testA 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....
would indicate inflammation (as indicated by a raised white blood cellWhite blood cellWhite blood cells, or leukocytes , are cells of the immune system involved in defending the body against both infectious disease and foreign materials. Five different and diverse types of leukocytes exist, but they are all produced and derived from a multipotent cell in the bone marrow known as a...
count and elevated C-reactive proteinC-reactive proteinC-reactive protein is a protein found in the blood, the levels of which rise in response to inflammation...
). - Neutrophils infiltrate the lung tissue, aided by damage to the airways caused by irritation.
- Damage caused by irritation of the airways leads to inflammation and leads to neutrophils being present
- Mucosal hypersecretion is promoted by a substance released by neutrophils
- Further obstruction to the airways is caused by more goblet cells in the small airways. This is typical of chronic bronchitis
- Although infection is not the reason or cause of chronic bronchitis it is seen to aid in sustaining the bronchitis.
- High Resolution Computed Tomography (HRCT) — This is a special type of CT scan that provides your doctor with high-resolution images of your lungs. Having a HRCT is no different than having a regular CT scan; they both are performed on an open-air table and take only a few minutes.
Antibiotics
Only about 5-10% of bronchitis cases are caused by a bacterial infection. Most cases of bronchitis are caused by a viral infection and are "self-limited" and resolve themselves in a few weeks. For acute exacerbations of chronic bronchitis, if antibiotics are used, amoxicillinAmoxicillin
Amoxicillin , formerly amoxycillin , and abbreviated amox, is a moderate-spectrum, bacteriolytic, β-lactam antibiotic used to treat bacterial infections caused by susceptible microorganisms. It is usually the drug of choice within the class because it is better absorbed, following oral...
or doxycycline
Doxycycline
Doxycycline INN is a member of the tetracycline antibiotics group, and is commonly used to treat a variety of infections. Doxycycline is a semisynthetic tetracycline invented and clinically developed in the early 1960s by Pfizer Inc. and marketed under the brand name Vibramycin. Vibramycin...
is recommended.
Bronchodilators
IpratropiumIpratropium
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...
is an example of a bronchodilator that may be useful for people suffering from chronic obstructive pulmonary disease, such as chronic bronchitis.
Albuterol is also a common drug for this disease.
Acute exacerbations
Acute exacerbations of chronic bronchitis (AECB) are episodes of difficulty in breathing in a person with chronic bronchitis.During AECB, breathing becomes much more difficult because of further narrowing of the airways, in addition to increased secretion of mucus, which often is thicker than usual.
Treatment of AECB may include:
- Cough suppressants
- Inhaled bronchodilatorBronchodilatorA bronchodilator is a substance that dilates the bronchi and bronchioles, decreasing resistance in the respiratory airway and increasing airflow to the lungs. Bronchodilators may be endogenous , or they may be medications administered for the treatment of breathing difficulties...
s - Antibiotics are used if a bacterial infection is the suspected cause. However, antibiotics will not treat exacerbations caused by viruses.
- CorticosteroidCorticosteroidCorticosteroids are a class of steroid hormones that are produced in the adrenal cortex. Corticosteroids are involved in a wide range of physiologic systems such as stress response, immune response and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte...
s - TheophyllineTheophyllineTheophylline, also known as dimethylxanthine, is a methylxanthine drug used in therapy for respiratory diseases such as COPD and asthma under a variety of brand names. Because of its numerous side-effects, the drug is now rarely administered for clinical use. As a member of the xanthine family, it...
- Oxygen therapyOxygen therapyOxygen therapy is the administration of oxygen as a medical intervention, which can be for a variety of purposes in both chronic and acute patient care...