Table 1.

American College of Physicians (ACCP)/Society of Critical Care Medicine (SCCM) Consensus Definitions for SIRS, Infection, Sepsis, Severe Sepsis, and Septic Shock

Systemic Inflammatory Response Syndrome (SIRS)

The presence of at least two of the following four criteria, one of which must be abnormal temperature or leukocyte count: Core temperature > 38°C or <36°C (by rectal, bladder, oral or central catheter probe) Tachycardia, defined as heart rate > 90/min Tachypnea, defined as respiratory rate > 20/min or PaCO2 < 32 mm Hg White blood cell count > 12,000 cells/μL or < 4,000 cells/μL

Infection

A suspected or proven (i.e. by positive culture, tissue stain, polymerase chain reaction, etc) infection caused by any pathogen OR a clinical syndrome associated with a high probability of infection (e.g. presence of white blood cells in a normally sterile body fluid, chest radiograph consistent with pneumonia, petechial or purpuric rash, etc)

Sepsis

SIRS + Infection

Severe Sepsis (Sepsis with Organ Dysfunction)

Sepsis plus either cardiovascular dysfunction or acute respiratory distress syndrome (ARDS) OR two or more other organ dysfunctions

Septic Shock

Severe Sepsis with arterial hypotension defined by a systolic blood pressure below 90 mm Hg, mean arterial pressure (MAP) < 60 mm Hg, or a reduction in systolic blood pressure >40 mm Hg from baseline, despite adequate volume resuscitation and in the absence of other causes for hypotension.

Adapted from [1]