Many terms are used to describe septic disorders, but they are not interchangeable. Here is a guide to recognizing the difference between sepsis, severe sepsis and septic shock:
Known or suspected infection and two or more signs of systemic inflammatory response syndrome (SIRS). Criteria for SIRS are:
- Temperature above 100.4˚ F (38˚ C) or below 96.8˚ F (36˚ C)
- Heart rate above 90 beats/minute
- Respiratory rate above 20 breaths/minute or partial pressure of carbon dioxide below 32 mm Hg (or mechanical ventilation)
- White blood cell count above 12,000 cells/mm3, below 4,000 cells/mm3, or with more than 10% immature neutrophils
Sepsis and failure of one or more organ systems, perfusion abnormalities, or hypotension. It is manifested by such disorders as lactic acidosis, leukopenia, thrombocytopenia, pulmonary congestion, and pulmonary edema.
Severe sepsis and refractory perfusion abnormalities or hypotension. It is manifested by multiple organ dysfunction syndrome (MODS) plus failure of two or more organ systems. Death occurs if MODS is not reversed.