FIG 1.

Venn diagram illustrating that sepsis lies at the intersection of infection and the systemic infection response syndrome (SIRS). Culture-proven infection is not a requirement, but a high clinical suspicion of infection suffices to define sepsis. The source of infection need not be blood/bacteremia but could be respiratory or abdominal or involve other sites. Many other noninfectious clinical conditions can lead to a clinical picture of SIRS, including major trauma or surgery, extensive burns, and pancreatitis, to name a few.