- Patient with clinical suspicion of infection and presenting at leat two of the following criteria:temperature > 38oC or < 36oC, heart rate > 90 beats/minute, respiratory rate > 20 breaths/minute or PaCO2 < 32 mmHg or leukocytosis >12 000/μl or leukopenia <4000/μl or normal white blood cell count with >10% immature forms