Definition of sepsis syndromes
| Systemic inflammatory response syndrome (SIRS) | |
| Defined by the presence of two of the following | |
| ▸Temperature >38°C or <36°C | |
| ▸Heart rate >90 per minute | |
| ▸Respiratory rate >20 breaths/min or Paco2 < 32 mm Hg (4.3 kPa) | |
| ▸White cell count >12000 or <4000 cells/mm3, or >10% immature forms | |
| Sepsis | |
| SIRS with evidence of infection | |
| Severe sepsis | |
| Sepsis associated with: | |
| ▸Organ dysfunction | |
| ▸Hypotension (systolic pressure <90 mm Hg or fall >40 mm Hg) | |
| ▸Hypoperfusion (manifest as lactic acidosis, oliguria, altered mental state) | |
| Refractory shock | |
| Shock refractory to conventional treatment (fluids, inotropes, vasoactive agents) within 1 hour | |
| Multiple system organ failure | |
| The presence of altered organ function in an acutely ill patient such that homeostasis cannot be maintained without intervention | |
| Acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS) (The 1994 Consensus Conference definition) | |
| ▸Onset | Acute and persistent |
| ▸Oxygenation criteria | Pao2/Fio2 ⩽300 for ALI |
| Pao2/Fio2 ⩽200 for ARDS | |
| ▸Exclusion criteria | PAOP ⩾18 mm Hg |
| Clinical evidence of left atrial hypertension | |
| ▸Radiographic criteria | Bilateral opacities consistent with pulmonary oedema |