Table 1.

Definitions of sepsis.

Criteria for SIRSa

Two or more of the following are required:

• Body temperature >38 °C or <36 °C

• Heart rate >90 beats/min

• Respiratory rate >20 breaths/min (or arterial pCO2 <32 mmHg, indicating hyperventilation)

• White blood cell count >12.0 × 109/L or <4.0 × 109/L (or >10% immature forms)

Sepsis = Infection + SIRS

Severe sepsis = Sepsis + evidence of organ dysfunction

The 2001 update to the Definitions stresses that documentation of infection may not be required for the diagnosis of sepsis if strong suspicion exists. Additional criteria, such as altered mental status, edema, hyperglycemia in the absence of diabetes, and elevated CRP or elevated PCT, are also included.

^aSee references Wang et al.³ and Ulevitch and Tobias⁴.