a. Presence of two or more of the following: i. A core temp ≥38C or ≤36C; ii. A heart rate ≥90 beats/min; iii. A respiratory rate ≥ 20 breaths/min or PaCO2 ≤32mmHg or use of mechanical ventilation for an acute process; iv. A white blood cell count ≥12000/ml or ≤4000/ml or immature neutrophils > 10%.