Table 1.

Adapted from ACCP/SCCM consensus statement.

	Definition
SIRS
Criteria	Two or more of the following
	Temperature > 38°C or < 36°C
	Heart rate > 90 beats per minute
	Respiratory rate > 20 breaths per minute or PaCO2 < 32 mm Hg
	White blood cell count > 12,000/cu mm, < 4,000/cu mm or
	> 10% immature (band) forms
Sepsis	The systemic response to infection manifested by 2 or more SIRS criteria
Severe sepsis	Sepsis associated with organ dysfunction, hypoperfusion or hypotension that may include but are not limited to, lactic acidosis, oliguria or an acute alteration in mental status
Septic shock	Sepsis-induced with hypotension despite adequate fluid resuscitation along with the presence of perfusion abnormalities that may include, but are not limited to, lactic acidosis, oliguria, or an acute alteration in mental status. Patients who are receiving inotropic or vasopressor agents may not be hypotensive at the time that perfusion abnormalities are measured.
Sepsis-induced hypotension	A systolic blood pressure < 90 mm Hg or a reduction of >/− 40 mm Hg from baseline in the absence of other causes for hypotension
MODS	Presence of altered organ function in acutely ill patients such that homeostasis cannot be maintained without intervention

ACCP, American College of Chest Physicians; SCCM, Society of Critical Care Medicine; SIRS, systemic inflammatory response syndrome; PaCO2, partial pressure of carbon dioxide in arterial blood; MODS, multiple organ dysfunction syndrome.