The Adult Respiratory Distress Syndrome: Clinical Features, Factors Influencing Prognosis and Principles of Management

Abstract

The adult respiratory distress syndrome (ARDS) is an important and common medical emergency and is likely to occur in all hospitals dealing in respiratory care. The syndrome occurs from a variety of diffuse pulmonary injuries which are either direct or indirect attacks on the lung parenchyma. Once lung damage occurs, exudation of fluid and loss of surfactant activity leads to impaired gas exchange and reduced pulmonary compliance. The syndrome presents clinically as marked respiratory distress, tachypnea, cyanosis, refractory hypoxemia, high inflation pressure requirements during ventilatory support, diffuse alveolar infiltrates on chest roentgenograms and postmortem pulmonary congestion, hyperemia and hyaline membrane formation. Principles of management include adequate support of oxygen transport, ventilation and circulation employing volume respirators with positive end-expiratory pressure (PEEP). During the support phase, further pulmonary injury in terms of fluid overload, oxygen toxicity or infection, must be prevented or treated. When these principles of management are followed, recovery often occurs in spite of severe pulmonary injury as indicated by the first two illustrative cases.