Four definitions you must know: SIRS \u2013 Must have at least 2 of 4 SIRS criteria (listed below): Fever (>38C) or Hypothermia (<36C) WBC >12k or <4k ; OR Bandemia >10% Tachycardia > 90 Tachypnea > 20 SEPSIS \u2013 Must have SIRS + have a suspected infectious source (eg pulmonary, urinary, intra-abdominal, etc) SEVERE SEPSIS [\u2026]