Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is a highly lethal (>40% mortality) form of acute hypoxemic respiratory failure that may account for as many as 10% of all admissions to the intensive care unit. Nearly any type of infectious or inflammatory insult can cause ARDS, either by direct (primary) lung injury or by systemic (secondary) injury. The cornerstones of ARDS treatment are low tidal volume ventilation, positive end-expiratory pressure, conservative fluid management, and prone positioning, although different ARDS sub-phenotypes (hyperinflammatory versus hypoinflammatory) may respond differently to interventions. Salvage therapies for refractory hypoxemia include provision of corticosteroids (e.g., dexamethasone, methylprednisolone, or hydrocortisone), neuromuscular blockade (e.g., cisatracurium), inhaled pulmonary vasodilators (e.g., inhaled nitric oxide or epoprostenol), and/or support with veno-venous extracorporeal membrane oxygenation. Extracorporeal membrane oxygenation circuits may alter the pharmacokinetics of certain medications, such as sedatives and antibiotics. Survivors of ARDS may experience long-term neuropsychiatric sequelae of their critical illness, including higher rates of anxiety, depression, and post-traumatic stress disorder. These sequelae might be mitigated by daily awakening trials to reduce sedative exposure, liberal glycemic control to avoid hypoglycemia, and early mobility to improve physical conditioning.