bronchitis

(brong-kīt′ĭs)

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[broncho- + -itis]
Inflammation of the mucous membranes of the bronchial airways, caused by irritation or infection, or both, by pathogen. Bronchitis can be acute or chronic.

CAUSES
Bronchitis is caused by infectious agents such as viruses (particularly rhinoviruses, influenza A and B, parainfluenza, adenoviruses, and respiratory syncytial virus) or, less often, by species of Mycoplasma, Chlamydia, streptococcus, Haemophilus, Branhamella, or staphylococcus. Infection is often indistinguishable from the common cold and is usually treated as such unless pneumonia is also present. Acute bronchial irritation (noninfectious bronchitis) may also be caused by exposure to various physical and chemical agents such as dust, fumes, or pollens. Allergies and preexisting conditions such as asthma or chronic obstructive lung disease may be important cofactors.

PATIENT CARE
A history is obtained documenting tobacco use, including type, duration, and frequency. Calculation of pack-year history gives useful information. The health care provider assesses for other known respiratory irritants and allergens, exertional or worsening dyspnea, and productive cough. The patient is evaluated for changes in baseline respiratory function such as the use of accessory muscles in breathing, cyanosis, neck vein distention, pedal edema, prolonged expiratory time, tachypnea, and wheezes or crackles. The color (gray, white, or yellow) and characteristics of sputum are often documented but may have little diagnostic significance. Tests such as arterial blood gas analysis, chest x-rays, oximetry, peak flow measurements, pulmonary function testing, and sputum Gram stain are occasionally employed. They are explained to the patient if they have been ordered. Prescribed antihistamines, bronchodilators, corticosteroids, decongestants, expectorants, and other medications are administered and the response is documented. Antibiotics are rarely indicated. Daily activities are interspersed with rest periods to conserve energy and to prevent fatigue. Patients with comorbid conditions should be hospitalized, in which case all general patient care concerns apply. Patients needing help to quit smoking are given counseling and support and referred to smoking cessation programs and for adjunctive drug therapy when prescribed.

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