Severe sepsis requires suspected or proven infection, organ failure, and signs that meet two or more criteria for the systemic inflammatory response syndrome (SIRS). The article Systemic Inflammatory Response Syndrome Criteria in Defining Severe Sepsis recently published on NEJM aimed to test the sensitivity, face validity, and construct validity of this approach.

Summary

Severe sepsis is a major cause of admission to the intensive care unit (ICU) and death. The criteria according to the systemic inflammatory response syndrome (SIRS) were described 23 years ago as a clinical expression of the host response to inflammation. In this context and in the presence of symptoms meeting two or more SIRS criteria, severe sepsis was seen as evolving from infection to sepsis, severe sepsis, and septic shock, in order of increasing severity. This approach was codified by the consensus statement of the American College of Chest Physicians and Society of Critical Care Medicine in 1992 and has been the predominant approach to classifying sepsis. The consensus definition of severe sepsis requires suspected or proven infection, organ failure, and signs that meet two or more criteria for the systemic inflammatory response syndrome (SIRS). This approach has been criticized because of a low specificity for infection within 24 hour after admission to the ICU. The retrospective study aimed to test the sensitivity, face validity, and construct validity of this approach.  

The study involved patients from 172 intensive care units in Australia and New Zealand from 2000 through 2013. In the study were identified patients with infection and organ failure and categorized according to whether they had signs meeting two or more SIRS criteria (SIRS-positive severe sepsis) or less than two SIRS criteria (SIRS negative severe sepsis). In the study characteristics and outcomes were compared and patients were assessed for the presence of a steep increase in the risk of death at a threshold of two SIRS criteria.

The need for two or more SIRS criteria to define severe sepsis excluded one in eight otherwise similar patients with infection, organ failure, and substantial mortality and failed to define a transition point in the risk of death.

Authors: Kirsi-Maija Kaukonen, Michael Bailey, David Pilcher, D. Jamie Cooper, and Rinaldo Bellomo