Lower respiratory infections BRONCHITIS Acute Bronchitis Bronchitis refers

Lower respiratory infections

BRONCHITIS • Acute Bronchitis: • Bronchitis refers to an inflammatory condition of the large elements of the tracheobronchial tree that is usually associated with a generalized respiratory infection. • The inflammatory process does not extend to include the alveoli. • The disease entity is frequently classified as either acute or chronic. • Acute bronchitis occurs in all ages, whereas chronic bronchitis primarily affects adults.

• Acute bronchitis most commonly occurs during the winter months. Cold, damp climates and/or the presence of high concentrations of irritating substances such as air pollution or cigarette smoke may precipitate attacks. • Respiratory viruses are by far the most common infectious agents associated with acute bronchitis. • The common cold viruses including rhinovirus and coronavirus and lower respiratory tract pathogens including influenza virus, adenovirus, and respiratory syncytial virus, account for the majority of cases. • Mycoplasma pneumoniae also appears to be a frequent cause of acute bronchitis. Other bacterial causes are Chlamydia pneumoniae and Bordetella pertussis.

• Infection of the trachea and bronchi causes hyperemic and edematous mucous membranes and an increase in bronchial secretions. • Destruction of respiratory epithelium can range from mild to extensive and may affect bronchial mucociliary function. • In addition, the increase in bronchial secretions, which can become thick and tenacious, further impairs mucociliary activity. • Recurrent acute respiratory infections may be associated with increased airway hyperreactivity and possibly the pathogenesis of chronic obstructive lung disease.

Clinical Presentation • Acute bronchitis usually begins as an upper respiratory infection. The patient typically has nonspecific complaints, such as malaise and headache, coryza, and sore throat. • Cough is the hallmark of acute bronchitis. It occurs early and will persist despite the resolution of nasal or nasopharyngeal complaints. • Frequently, the cough is initially nonproductive but progresses, yielding mucopurulent sputum.

• Goals of Therapy: Treatment ü The goal is to provide comfort to the patient and, in the unusually severe case, to treat associated dehydration and respiratory compromise. Ø The treatment of acute bronchitis is symptomatic and supportive in nature. ü Reassurance and antipyretics alone are often sufficient. ü Bed rest and mild analgesic antipyretic therapy are often helpful in relieving the associated lethargy, malaise, and fever. ü Patients should be encouraged to drink fluids to prevent dehydration and possibly decrease the viscosity of respiratory secretions. • Aspirin or acetaminophen (650 mg in adults or 10– 15 mg/kg per dose in children with a maximum daily adult dose of <4 g and 60 mg/kg for children) or ibuprofen.

• Mist therapy and/or the use of a vaporizer may further promote thinning and loosening of respiratory secretions. In otherwise healthy patients, no meaningful benefits have been described with the use of oral or aerosolized β 2 -receptor agonists and/or oral or aerosolized corticosteroids. • Persistent, mild cough, which may be bothersome, may be treated with dextromethorphan; more severe coughs may require intermittent codeine or other similar agents. • Routine use of antibiotics in the treatment of acute bronchitis is discouraged; however, in patients who exhibit persistent fever or respiratory symptomatology for more than 4 to 6 days, the possibility of a concurrent bacterial infection should be suspected. • When possible, antibiotic therapy is directed toward anticipated respiratory pathogen(s).

Treatment • The patient will most likely benefit from antibiotic therapy if two or three of the following are present: (1) increase of shortness of breath. (2) increase in sputum volume. (3) production of purulent sputum.

Pneumonia • Pneumonia is the most common infectious cause of death in the United States. • It occurs in persons of all ages, although the clinical manifestations are most severe in the very young, the elderly, and the chronically ill.

Pneumonia • Gram-Positive and Gram-Negative Bacterial Pneumonia • Anaerobic Pneumonia • Mycoplasma pneumoniae • Viral Pneumonia • Hospital-acquired Pneumonia

TREATMENT • Eradication of the offending organism and complete clinical cure are the primary objectives. • Associated morbidity should be minimized (eg, renal, pulmonary, or hepatic dysfunction). • The first priority on assessing the patient with pneumonia is to evaluate the adequacy of respiratory function and to determine whethere are signs of systemic illness, specifically dehydration, or sepsis with resulting circulatory collapse.

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