Acute exacerbations of chronic bronchitis
Encyclopedia
Acute exacerbations of chronic bronchitis (AECB) are episodes of difficulty in breathing in a person with chronic bronchitis
.
In concomitant presence of emphysema
, the underlying condition can be classified as chronic obstructive pulmonary disease
(COPD), and the exacerbations termed "acute exacerbation of COPD
", and shares many characteristics with that of AECB.
Although the condition of a patient with chronic bronchitis can become exacerbated by many other factors as well, the scope is generally restricted to the ones that cause the symptoms below.
In infection, there is often weakness, fever and chills. If due to a bacterial infection, the sputum may be slightly streaked with blood and coloured yellow or green.
and may be thicker than usual, but without evidence of pneumonia
(which involves mainly the alveoli rather than the bronchi). Also, diagnostic criteria may include an increased in frequency and severity of cough, as well as increased shortness of breath.
A chest X-ray
is usually performed on people with fever and, especially, hemoptysis
(blood in the sputum), to rule out pneumonia and get information on the severity of the exacerbation. Hemoptysis may also indicate other, potentially fatal, medical conditions.
A history of exposure to potential causes and evaluation of symptoms may help in revealing the cause of an acute exacerbation of chronic bronchitis, which helps in choosing the best treatment. A sputum culture
can specify which strain is causing a bacterial AECB. An early morning sample is preferred.
Treatment of AECB may include:
There should also be a "care plan" in case of future exacerbations. Patients may watch for symptoms, such as shortness of breath, change in character or amount of mucus, and start self-treatment as discussed with a health care provider. This allows for treatment right away until a doctor can be seen.
Chronic bronchitis
Chronic bronchitis is a chronic inflammation of the bronchi in the lungs. It is generally considered one of the two forms of chronic obstructive pulmonary disease...
.
In concomitant presence of 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...
, the underlying condition can be classified as 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), and the exacerbations termed "acute exacerbation of COPD
Acute exacerbation of chronic obstructive pulmonary disease
An acute exacerbation of COPD is a sudden worsening of COPD symptoms that typically lasts for several days. It may be triggered by an infection with bacteria or viruses or by environmental pollutants...
", and shares many characteristics with that of AECB.
Incidence
The incidence of AECB varies depending on which definition is used, but by AECB definitions by Anthonisen et al. the typical COPD patient averages two to three AECB episodes per year. With a COPD prevalence of more than 12 million (possibly 24 million including undiagnosed ones) in the United States, there are at least 30 million incidences of AECB annually in the US.Pathogenesis
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.Causes
AECB can be caused by:- Allergens, e.g., pollens, wood or cigarette smoke, pollution
- Toxins, including a variety of different chemicals
- Acute viral or bacterial infections. The extra mucus in the airways in chronic bronchitis provides a good place for viruses and bacteria to grow. Bacterial infections are suspected when there is a yellow or greenish colour of the mucus, or it is thicker than usual. However, coloured mucus is not specific to bacterial infections. Common bacterial pathogens of acute exacerbations include Haemophilus influenzaeHaemophilus influenzaeHaemophilus influenzae, formerly called Pfeiffer's bacillus or Bacillus influenzae, Gram-negative, rod-shaped bacterium first described in 1892 by Richard Pfeiffer during an influenza pandemic. A member of the Pasteurellaceae family, it is generally aerobic, but can grow as a facultative anaerobe. H...
, Streptococcus pneumoniaeStreptococcus pneumoniaeStreptococcus pneumoniae, or pneumococcus, is Gram-positive, alpha-hemolytic, aerotolerant anaerobic member of the genus Streptococcus. A significant human pathogenic bacterium, S...
and Moraxella catarrhalisMoraxella catarrhalisMoraxella catarrhalis is a fastidious, nonmotile, Gram-negative, aerobic, oxidase-positive diplococcus that can cause infections of the respiratory system, middle ear, eye, central nervous system and joints of humans.-History:...
. Less common bacterial pathogens include Chlamydia pneumoniae and MRSAMethicillin-resistant Staphylococcus aureusMethicillin-resistant Staphylococcus aureus is a bacterium responsible for several difficult-to-treat infections in humans. It is also called multidrug-resistant Staphylococcus aureus and oxacillin-resistant Staphylococcus aureus...
. Pathogens seen more frequently in patients with impaired lung function (FEV<35% of predicted) include Haemophilus parainfluenzaeHaemophilus parainfluenzaeHaemophilus parainfluenzae is a species of Haemophilus.It is one of the HACEK organisms....
(after repeated use of antibiotics), Mycoplasma pneumoniaeMycoplasma pneumoniaeMycoplasma pneumoniae is a very small bacterium in the class Mollicutes.It causes the disease mycoplasma pneumonia, a form of atypical bacterial pneumonia, and is related to cold agglutinin disease.-Cell wall/Treatment:...
and gram-negativeGram-negativeGram-negative bacteria are bacteria that do not retain crystal violet dye in the Gram staining protocol. In a Gram stain test, a counterstain is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color...
, opportunistic pathogens like Pseudomonas aeruginosaPseudomonas aeruginosaPseudomonas aeruginosa is a common bacterium that can cause disease in animals, including humans. It is found in soil, water, skin flora, and most man-made environments throughout the world. It thrives not only in normal atmospheres, but also in hypoxic atmospheres, and has, thus, colonized many...
and Klebsiella pneumoniaeKlebsiella pneumoniaeKlebsiella pneumoniae is a Gram-negative, non-motile, encapsulated, lactose fermenting, facultative anaerobic, rod shaped bacterium found in the normal flora of the mouth, skin, and intestines....
.
Although the condition of a patient with chronic bronchitis can become exacerbated by many other factors as well, the scope is generally restricted to the ones that cause the symptoms below.
Symptoms
An acute exacerbation of chronic bronchitis is associated with increased frequency and severity of coughing. It is often accompanied by worsened chest congestion and discomfort. Shortness of breath and wheezing are present in many cases.In infection, there is often weakness, fever and chills. If due to a bacterial infection, the sputum may be slightly streaked with blood and coloured yellow or green.
Diagnosis
The diagnostic criteria for acute exacerbation of chronic bronchitis generally include an production of sputum that is purulentPus
Pus is a viscous exudate, typically whitish-yellow, yellow, or yellow-brown, formed at the site of inflammatory during infection. An accumulation of pus in an enclosed tissue space is known as an abscess, whereas a visible collection of pus within or beneath the epidermis is known as a pustule or...
and may be thicker than usual, but without evidence of 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...
(which involves mainly the alveoli rather than the bronchi). Also, diagnostic criteria may include an increased in frequency and severity of cough, as well as increased shortness of breath.
A chest X-ray
Chest X-ray
In 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...
is usually performed on people with fever and, especially, hemoptysis
Hemoptysis
Hemoptysis or haemoptysis is the expectoration of blood or of blood-stained sputum from the bronchi, larynx, trachea, or lungs Hemoptysis or haemoptysis is the expectoration (coughing up) of blood or of blood-stained sputum from the bronchi, larynx, trachea, or lungs Hemoptysis or haemoptysis ...
(blood in the sputum), to rule out pneumonia and get information on the severity of the exacerbation. Hemoptysis may also indicate other, potentially fatal, medical conditions.
A history of exposure to potential causes and evaluation of symptoms may help in revealing the cause of an acute exacerbation of chronic bronchitis, which helps in choosing the best treatment. A sputum culture
Sputum culture
A sputum culture is a test to detect and identify bacteria or fungi that infect the lungs or breathing passages. Sputum is a thick fluid produced in the lungs and in the adjacent airways. A sample of sputum is placed in a sterile container and sent to the laboratory for testing...
can specify which strain is causing a bacterial AECB. An early morning sample is preferred.
Prevention
Prevention of AECB include:- Smoking cessationSmoking cessationSmoking cessation is the process of discontinuing the practice of inhaling a smoked substance. This article focuses exclusively on cessation of tobacco smoking; however, the methods described may apply to cessation of smoking other substances that can be difficult to stop using due to the...
and avoiding dust, passive smokingPassive smokingPassive smoking is the inhalation of smoke, called secondhand smoke or environmental tobacco smoke , from tobacco products used by others. It occurs when tobacco smoke permeates any environment, causing its inhalation by people within that environment. Exposure to secondhand tobacco smoke causes...
, and other inhaled irritants - Yearly influenza and pneumococcal vaccinePneumococcal vaccineA pneumococcal vaccine is a vaccine against Streptococcus pneumoniae.Types include:* Pneumococcal polysaccharide vaccine* Pneumococcal conjugate vaccine-Vaccination in the USA:...
- Regular exercise, appropriate rest, and healthy nutrition
- Avoiding people currently infected with e.g. cold and influenza
- Maintaining good fluid intake and humidifying the home, in order to help reduce the formation of thick sputum and chest congestion.
Treatment
Treatment is often started before the test results confirm the condition.Treatment of AECB may include:
- Mucolytic agentMucolytic agentMucokinetics are a class of drugs which aid in the clearance of mucous from the airways, lungs, bronchi, and trachea. Such drugs can be further categorized by their mechanism of action.* expectorants* mucolytic agents...
s may be used to help liquefy thick mucus, facilitating clearance from the airways. Thinning of mucus may also be done by drinking plenty of fluids. - 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 open up the airways in the lungs. These include salbutamolSalbutamolSalbutamol 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....
and terbutalineTerbutalineTerbutaline is a β2-adrenergic receptor agonist.Terbutaline is currently on the World Anti-Doping Agency's list of prohibited drugs for Olympic athletes, except when administered by inhalation and a Therapeutic Use Exemption has been obtained in advance.Terbutaline is currently used to delay...
(both β2-adrenergic agonists), and ipratropium (an anticholinergicAnticholinergicAn anticholinergic agent is a substance that blocks the neurotransmitter acetylcholine in the central and the peripheral nervous system. An example of an anticholinergic is dicycloverine, and the classic example is atropine....
). - Antibiotics are used if a bacterial infection is the suspected cause. However, antibiotics will not treat exacerbations caused by viruses. Viral infections will usually be cured with time with the aid of proper rest and care. Still, other medications may be needed to control symptoms. Lipid-soluble antibiotics such as macrolideMacrolideThe macrolides are a group of drugs whose activity stems from the presence of a macrolide ring, a large macrocyclic lactone ring to which one or more deoxy sugars, usually cladinose and desosamine, may be attached. The lactone rings are usually 14-, 15-, or 16-membered...
s, tetracyclines, and quinoloneQuinoloneThe quinolones are a family of synthetic broad-spectrum antibiotics. The term quinolone refers to potent synthetic chemotherapeutic antibacterials....
s penetrate the lung tissue well. Macrolides are more active against Streptococcus pneumoniaeStreptococcus pneumoniaeStreptococcus pneumoniae, or pneumococcus, is Gram-positive, alpha-hemolytic, aerotolerant anaerobic member of the genus Streptococcus. A significant human pathogenic bacterium, S...
than the tetracyclines and the older quinolones. Within the macrolides, newer ones are more active against Haemophilus influenzaeHaemophilus influenzaeHaemophilus influenzae, formerly called Pfeiffer's bacillus or Bacillus influenzae, Gram-negative, rod-shaped bacterium first described in 1892 by Richard Pfeiffer during an influenza pandemic. A member of the Pasteurellaceae family, it is generally aerobic, but can grow as a facultative anaerobe. H...
than the older erythromycin. Regimens should generally be given for five days. Choice of antibiotics is also dependent on the severity of chronic bronchitis:- "Simple" chronic bronchitis is generally where the patient is 65 years or less, has fewer than four exacerbations per year, has minimal or moderate impairment in respiratory function and no comorbid diseaseComorbidityIn medicine, comorbidity is either the presence of one or more disorders in addition to a primary disease or disorder, or the effect of such additional disorders or diseases.- In medicine :...
. In patients with "simple" chronic bronchitis, therapy should be targeted towards Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae, and possibly pathogens of atypical pneumoniaAtypical pneumoniaAtypical pneumonia aka "walking pneumonia" is a pneumonia not caused by one of the more traditional pathogens, and with a clinical presentation inconsistent with typical pneumonia. It can be caused by a variety of microorganisms...
. The first-line treatment is a beta-lactam antibioticBeta-lactam antibioticβ-Lactam antibiotics are a broad class of antibiotics, consisting of all antibiotic agents that contains a β-lactam nucleus in its molecular structure. This includes penicillin derivatives , cephalosporins , monobactams, and carbapenems...
such as amoxicillinAmoxicillinAmoxicillin , 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...
. The choice will depend on resistance patterns. In patients with penicillin allergy, doxycyclineDoxycyclineDoxycycline 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...
or trimethoprimTrimethoprimTrimethoprim is a bacteriostatic antibiotic mainly used in the prophylaxis and treatment of urinary tract infections.It belongs to the class of chemotherapeutic agents known as dihydrofolate reductase inhibitors...
are preferred. - More complicated bronchitis may be when the patient is more than 65 years old, has four or more exacerbations per year, has an FEV1/FVC ratioFEV1/FVC ratioThe FEV1/FVC ratio, also called Tiffeneau index, is a calculated ratio used in the diagnosis of obstructive and restrictive lung disease.It represents the proportion of the forced vital capacity exhaled in the first second....
of less than 50% on 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...
, has failed to respond to previous antibiotic treatment, and/or has comorbidity. In these cases, treatment should be aimed at Gram-negative bacteria and the possibility of high antibiotic resistanceAntibiotic resistanceAntibiotic resistance is a type of drug resistance where a microorganism is able to survive exposure to an antibiotic. While a spontaneous or induced genetic mutation in bacteria may confer resistance to antimicrobial drugs, genes that confer resistance can be transferred between bacteria in a...
should be considered. Sputum culture results are of great value in determining antibiotic resistance. First-line treatment is cefuroximeCefuroximeCefuroxime is a second-generation cephalosporin antibiotic that has been widely available in the USA as Ceftin since 1977. GlaxoSmithKline sells the antibiotic in the United Kingdom under the name Zinnat.-Indications:As for the other cephalosporins, although as a...
or co-amoxiclavCo-amoxiclavAmoxicillin/clavulanic acid or co-amoxiclav is a combination antibiotic consisting of amoxicillin trihydrate, a β-lactam antibiotic, and potassium clavulanate, a β-lactamase inhibitor...
. Third-line treatment, as well as treatment in penicillin-allergic patients, is a fluoroquinolone such as ciprofloxacinCiprofloxacinCiprofloxacin is a synthetic chemotherapeutic antibiotic of the fluoroquinolone drug class.It is a second-generation fluoroquinolone antibacterial. It kills bacteria by interfering with the enzymes that cause DNA to rewind after being copied, which stops synthesis of DNA and of...
. An agent active against Streptococcus pneumoniae may have to be added.
- "Simple" chronic bronchitis is generally where the patient is 65 years or less, has fewer than four exacerbations per year, has minimal or moderate impairment in respiratory function and no comorbid disease
- 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 such as prednisonePrednisonePrednisone is a synthetic corticosteroid drug that is particularly effective as an immunosuppressant drug. It is used to treat certain inflammatory diseases and some types of cancer, but has significant adverse effects...
reduce inflammation in the airways. They are usually used for short periods. - 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...
, taken orally, helps to ease the difficulty of breathing. It may be added if the patient is not already taking it for the chronic bronchitis. - 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...
should be initiated if there is a substantial risk of hypoxiaHypoxia (medical)Hypoxia, or hypoxiation, is a pathological condition in which the body as a whole or a region of the body is deprived of adequate oxygen supply. Variations in arterial oxygen concentrations can be part of the normal physiology, for example, during strenuous physical exercise...
. If oxygen is required on an ongoing basis, a portable oxygen concentratorPortable oxygen concentratorPortable oxygen concentrator is a portable device used to provide oxygen therapy to a patient at substantially higher concentrations than the levels of ambient air. It is very similar to a home oxygen concentrator, but it smaller in size and more mobile...
can be used.
There should also be a "care plan" in case of future exacerbations. Patients may watch for symptoms, such as shortness of breath, change in character or amount of mucus, and start self-treatment as discussed with a health care provider. This allows for treatment right away until a doctor can be seen.