CLINICAL PRESENTATION AND DIAGNOSIS



As with any clinically defined syndrome, the diagnosis of ARDS is made by finding the appro­priate signs and symptoms in the proper clinical setting . Some pre­disposing conditions are more likely to result in ARDS than others, such as lung injury secondary to aspiration of gastric contents, pneumonias and sepsis requiring admission to the intensive care unit, and disseminated intravascular coagulopa­thy.

Clinical presentation is relatively uniform re­gardless of etiology. Initially signs and symptoms are limited to those of the primary disorder. How­ever, within the first 12 to 24 hours early accu­mulation of lung water causes dyspnea, hyper­ventilation, and the appearance of a fine diffuse reticular infiltrate on chest x-ray. Unless the un­derlying disease can be rapidly reversed, as in sepsis, the patient quickly progresses to the full­blown syndrome with the development of pro­gressive bilateral pulmonary infiltrates, severe hy­poxemia, and a dramatic fall in lung compliance. Most patients manifest respiratory failure within 24 hours of the onset of the predisposing event, and almost 90 per cent of those who eventually develop ARDS will do so by 72 hours. Treatment is generally supportive and directed at maintain­ing an adequate delivery of Oz to the tissues while minimizing iatrogenic complications. Therapy di­rected at the predisposing condition, when known, is imperative, since its continued pres­ence leads to the persistence of the ARDS.