Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is commonly associated with severe sepsis. While the criteria for diagnosis have evolved since the first description in 1967, the characteristics of hypoxemia, tachypnea, rapidly progressing acute respiratory failure, and poor lung compliance continue. Scoring systems have been developed in an effort to quantify the severity of lung injury, with the most recent being the Berlin Definition. This system attempts to define acute lung injury (ALI) and ARDS with more precision in terms of timing of disease onset, severity of disease, and chest radiograph findings. The number of reported cases of ALI/ARDS per year is lower in pediatric patients vs. adults; however, mortality rates continue to be high. Sepsisrelated ARDS has a generally higher disease severity and poorer recovery period from lung injury with an increased mortality rate. ARDS results from an initial insult (direct and/or indirect) which triggers a series of cell-mediated responses leading to damage to the capillary endothelium, alveolar epithelium, and impaired fluid removal from the alveolar space. There is, however, gradual resolution of hypoxemia, lung function, and radiographic abnormalities in survivors of ARDS. Management of ARDS is mainly supportive with specific mechanical ventilation strategies and goal-directed therapies. Prevention of ventilator-induced lung injury (VILI) has been demonstrated to have a positive impact on outcomes in patients with ARDS.