TABLE 1.

Clinical Scenarios Involving >1 Organ System Dysfunction

Description	Defining Features	Examples
MODS	More than 1 concurrent organ system dysfunction arising from a common systemic pathobiological mechanism (or mechanisms)	Sepsis-induced cardiovascular, respiratory, and kidney dysfunction from systemic inflammation and mitochondrial energy failure Trauma-induced cardiovascular, neurologic, and hepatic dysfunction from hemorrhage-induced global hypoperfusion Hypertensive emergency leading to cardiac dysfunction and neurologic dysfunction
Sequential organ dysfunction	A primary organ dysfunction induces a secondary organ system dysfunction, but the underlying mechanisms are different	Primary cardiac dysfunction from an arrhythmia leading to secondary respiratory dysfunction from cardiogenic pulmonary edema Primary liver failure from primary biliary cirrhosis leading to secondary neurologic dysfunction from hyperammonemia and cerebral edema Primary kidney dysfunction from glomerulonephritis leading to secondary cardiac dysfunction from hypertension
Unrelated organ dysfunction	More than 1 concurrent organ system dysfunction, with each organ system dysfunction caused by a different mechanism	Respiratory dysfunction from pneumonia and kidney dysfunction from aminoglycoside-induced acute tubular necrosis Cardiovascular dysfunction from sepsis and hematologic dysfunction from chemotherapy-induced bone marrow suppression

Note that each scenario is not mutually exclusive.