Table 1.

 Definitions of systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis, and shock

(1) Systemic inflammatory response syndrome (SIRS)

Systemic inflammatory response to a wide variety of severe clinical insults, manifested by two or more of the following conditions:

(i) Oral temperature >38°C or <36°C

(ii) Heart rate >90 beats/min

(iii) Respiratory rate >20 breaths/min or PaCO2 <32 mm Hg

(iv) WBC count >12 000/mm3, <4000/mm3, or >10% immature (band) forms.

(2) Sepsis

SIRS, as defined above, in response to a proven or suspected microbial event.

(3) Severe sepsis/SIRS

Sepsis (SIRS) associated with organ dysfunction, hypoperfusion, or hypotension, which may include, but are not limited to

lactic acidosis

oliguria

an acute alteration in mental status.

(4) Sepsis (SIRS) induced hypotension

Systolic blood pressure <90 mm Hg or a reduction of >40 mm Hg from baseline in the absence of other causes of hypotension.

(5) Septic shock/SIRS shock

Sepsis (SIRS) induced hypotension despite adequate fluid resuscitation along with organ dysfunction or perfusion abnormalities, as listed above for severe sepsis/SIRS.

(6) Refractory septic shock/SIRS shock

Sepsis (SIRS) induced shock that lasts for >1 hour and does not respond to fluid and pressor administration.

(7) Multiple organ dysfunction syndrome (MODS)

Dysfunction of more than one organ, requiring intervention to maintain homeostasis.