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Chapter 24 Coordinating Care for Patients With Infectious Respiratory Disorders
Right upper lobe pneumonia
atypical. Examples of atypical organisms are Mycoplasma , Chlamydophila (from handling birds), Legionella (present in intricate water delivery systems), and Bordetella pertussis (responsible for whooping cough). Connection Check 24.3 The correct statement about the prevalence of pneumonia is which of the following? A. Pneumonia is no longer a major health problem. B. The prevalence of pneumonia is increasing dramatically. C. The prevalence and mortality are highest in persons older than 65 years. D. The frequency has not declined, but mortality has declined. Pathophysiology Pneumonia is an inflammation of the lung parenchyma (functional lung tissue) resulting from a bacterial, viral, or fungal infection. Organisms enter the respiratory tract through inhalation of infected droplets or aspiration from the oropharynx. They evade the protective mechanisms of the respiratory tract and initiate the inflammatory process. The respiratory protective mechanisms become either ineffective or overwhelmed. An inflammatory cascade of events is initiated in response to the offending patho- gen. Inflammatory mediators stimulate the production and release of neutrophils and macrophages that travel to the site of infection. Organisms continue to proliferate at the alveolar level. As the inflammatory response unfolds, protein-rich fluid and exudates fill the alveoli, impairing the exchange of oxygen and CO 2 . A ventilation–perfusion mismatch results from adequate blood flow to a nonfunc- tioning, fluid-filled alveolar unit. Organisms can localize to one or more lobes ( lobar or multilobar pneumonia) or spread throughout the lung parenchyma, resulting in the diffuse location of organisms (Figs. 24.4A and B). Bacteria causing pneumococcal pneu- monia (S. pneumoniae) can gain access to the bloodstream, leading to septicemia and septic shock. Older individuals over the age of 65 years or those with chronic illness are at high risk for mortality from contracting this bacterial organism. Clinical Manifestations The clinical manifestations produced by the inflamma- tory response can vary from mild to severe and include the following: l Fever l Tachypnea/dyspnea l Tachycardia
A
B FIGURE 24.4 Localizing or diffuse pneumonia. A, Right upper lobe lobar pneumonia. B, Diffuse pneumonia.
l Chills l Cough, productive or nonproductive l Pleuritic chest pain l Fatigue l Myalgia/arthralgia In more severe forms, additional manifestations include the following: l Purulent or blood-streaked sputum Awareness of the clinical manifestations and predictors of increased mortality is essential to help ensure the speedy identification and treatment of pneumonia. Validated clin- ical predictors of increased mortality and morbidity from severe infectious pneumonia include the following: 1. Altered mental status 2. Respiratory rate greater than 30 breaths per minute 3. Hypotension (systolic blood pressure less than 90 mm Hg) l Hypotension l Dysrhythmias
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