Clinical and radiological diagnosis of community-acquired pneumonia in adults

Abstract

Community acquired pneumonia in adults is an acute disease characterized by worsening in general conditions, fever, chills, cough, mucopurulent sputum and dyspnea; associated with tachycardia, tachypnea, fever and focal signs in pulmonary examination. The probability of pneumonia in a patient with acute respiratory symptoms depends on the disease prevalence in the environment where it is acquired and on clinical features. It is estimated that pneumonia prevalence is 3-5% in patients with respiratory disease seen in outpatient facilities. Clinical diagnosis of pneumonia without radiological confirmation lacks specificity because clinical presentation (history and physical examination) does not allow to differentiate pneumonia from other acute respiratory diseases (upper respiratory infections, bronchitis, influenza). Diagnosis must be based in clinical-radiological findings: clinical history and physical examination suggest the presence of pulmonary infection but accurate diagnosis is established when chest X ray confirms the existence of pulmonary infiltrates. Clinical findings and chest X ray do not permit to predict with certainty the etiology of pulmonary infection. Radiology is useful to confirm clinical suspicion, it establishes pneumonia location, its extension and severity; furthermore, it allows differentiation between pneumonia and other diseases, to detect possible complications, and may be useful in follow up of high risk patients. The resolution of radiological infiltrates often ensues several weeks or months after clinical recovery, especially in the elderly and in multilobar pneumonia cared for in intensive care units.