Table 2.

Organ system dysfunction criteria^*

Organ system	Criteria
Cardiovascular	Arterial systolic blood pressure ≤90 mm Hg or mean arterial pressure ≤70 mm Hg for at least 1 hour despite adequate fluid resuscitation and adequate intravascular volume status or the use of vasopressors to maintain the above criteria
Kidney	Urine output <0.5 mL/kg/hr for 1 hour despite adequate fluid resuscitation
Respiratory	Ratio of PaO2 to FiO2 ≤250 in the presence of other organ system dysfunction or ≤200 if the lung was the only dysfunctional organ
Hematologic	Platelet count <80,000/μL or decreased by 50% in the 3 days preceding enrollment
Unexplained metabolic acidosis	pH ≤7.30 or base deficit ≥5.0 mmol/L in association with a plasma lactate level that was >1.5 times the upper limit of normal for the reporting laboratory

*From reference 9.