Proceso Enfermero De Gastroenteritis

Acute bronchitis is a clinical term implying a self-limited inflammation of the large
airways of the lung that is characterized by cough without pneumonia. The disorder
affects approximately 5% of adults annually,
with a higher incidence observed during the winter and fall than in the summer and spring. In the United States, acute
bronchitis is the ninth most common illness amongoutpatients, as reported by physicians.
Viruses are usually considered the cause of acute bronchitis but have been isolated
in a minority of patients.
Those isolated in acute bronchitis (from the most to the
least common in large series) include influenza A and B viruses, parainfluenza virus,
respiratory syncytial virus, coronavirus, adenovirus, and rhinovirus. Human metapneumovirus has beenidentified as a causative agent.
A recent French study involving adults who had been vaccinated against influenza showed a viral cause in 37%
of 164 cases of acute bronchitis, of which 21% were rhinovirus.
Thus, the yield of
specific pathogens varies according to several factors, including the presence or absence of an epidemic, the season of the year, and the influenza vaccination status ofthe population.
Bacterial species commonly implicated in community-acquired pneumonias are
isolated from the sputum in a minority of patients with acute bronchitis.
However,
the role of these species in the disease or its attendant symptoms remains unclear,
because bronchial biopsies have not shown bacterial invasion. In some cases, atypical bacteria are important causes, includingBordetella pertussis, Chlamydophila (Chlamydia)
pneumoniae, and Mycoplasma pneumoniae.
Some data have suggested that B. pertussis
may underlie 13 to 32% of cases of cough lasting 6 days or longer, although in a recent
prospective study, B. pertussis comprised only 1% of cases of acute bronchitis.
Pathobiology
Acute bronchitis is thought to reflect an inflammatory response to infections of theepithelium of the bronchi. Epithelial-cell desquamation and denuding of the airway
to the level of the basement membrane in association with the presence of a lymphocytic cellular infiltrate have been demonstrated after influenza A tracheobronchiti

microscopical examination has shown thickening
of the bronchial and tracheal mucosa corresponding to the inflamed areas. Such pathologicalfindings are consistent with reports of proximal
lower airway inflammation confined to the bronchi, as detected by positron-emission tomography
with
18
F-fluorodeoxyglucose as a tracer, in the
setting of acute bronchitis.
10
However, there are wide variations in the anatomical distribution of many pathogens that cause
acute bronchitis. In a study involving volunteers
exposed torhinovirus infections, for example,
virus was detected in specimens of induced sputum obtained from all the subjects, in approximately one third of bronchial biopsy specimens,
in almost a quarter of bronchoalveolar lavage
specimens, and in more than a third of bronchial
brushing specimens.
11
Such data indicating viral
infection of the lower airways may help to explain
the relationshipobserved between rhinovirus infection (and other presumed upper respiratory
viral infections) and exacerbation of asthma.
12
Thus, although its name suggests only large-airway disease, acute bronchitis may be accompanied
by an array of symptoms, depending on the degree of viral involvement of the large and small
airways.
Natural History
During the first few days of infection, the symptomsof mild upper respiratory infections cannot
be distinguished from those of acute bronchitis.
However, with acute bronchitis, coughing persists
for more than 5 days, and during this protracted
period the results of pulmonary function testing
may become abnormal. Forty percent of patients
have significant reductions in the forced expiratory volume in 1 second (i.e., a value below 80%...