Systemic Inflammatory Response Syndrome Criteria in Defining Severe Sepsis

The authors sought to validate the definition of the systemic inflammatory response syndrome (SIRS), which requires the presence of 2 or more clinical criteria, and determined whether meeting the definition was associated with an increased risk of death.  Over 109,000 ICU patients in Australia and New Zealand who had infection and organ failure were studied.  88% had SIRS positive sepsis, the others did not meet the SIRS criteria (SIRS negative sepsis).   Mortality in the two groups decreased similarly over the 14 year study.  There was a linear increase in mortality associated with each additional SIRS criterion, indicating that the threshold of 2 criteria did not represent a transition in risk level.