Acute respiratory distress syndrome | |
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Synonyms | respiratory distress syndrome (RDS), adult respiratory distress syndrome, shock lung |
Chest x-ray of patient with ARDS | |
Classification and external resources | |
Specialty | Critical care medicine |
ICD-10 | J80 |
ICD-9-CM | 518.5, 518.82 |
DiseasesDB | 892 |
MedlinePlus | 000103 |
eMedicine | article/165139 |
Patient UK | Acute respiratory distress syndrome |
MeSH | D012128 |
Acute (or Adult) respiratory distress syndrome (ARDS) is a medical condition occurring in critically ill patients characterized by widespread inflammation in the lungs. ARDS is not a particular disease, rather it is a clinical phenotype which may be triggered by various pathologies such as trauma, pneumonia and sepsis.
The hallmark of ARDS is diffuse injury to cells which form the alveolar barrier, surfactant dysfunction, activation of the innate immune response, and abnormal coagulation. In effect, ARDS results in impaired gas exchange within the lungs at the level of the microscopic alveoli.
The syndrome is associated with a high mortality rate between 20 and 50%. The mortality rate with ARDS varies widely based on severity, the patient's age, and the presence of other underlying medical conditions.
Although the terminology of "adult respiratory distress syndrome" has at times been used to differentiate ARDS from "infant respiratory distress syndrome" in neonates, international consensus is that "acute respiratory distress syndrome" is the best term because ARDS can affect those of all ages.
The signs and symptoms of ARDS often begin within two hours of an inciting event, but can occur after 1–3 days. Signs and symptoms may include shortness of breath, fast breathing, and a low oxygen level in the blood due to abnormal ventilation.
Diffuse compromise of the pulmonary system resulting in ARDS generally occurs in the setting of critical illness. ARDS may be seen in the setting of severe pulmonary (pneumonia) or systemic infection (sepsis), following trauma, multiple blood transfusions, severe burns, severe pancreatitis, near-drowning, drug reactions, or inhalation injuries. Some cases of ARDS are linked to large volumes of fluid used during post-trauma resuscitation.
Diagnostic criteria for ARDS have evolved over time, in step with an increasing understanding of both the pathophysiology and the limits of diagnostic capability in general practice. The international consensus criteria for ARDS were most recently updated in 2012 and are known as the "Berlin definition". In addition to generally broadening the diagnostic thresholds, other notable changes from the prior 1994 consensus criteria include discouraging the term "acute lung injury," and defining grades of ARDS severity according to degree of hypoxemia (see history).