Which of the following differentiates SIRS from sepsis -

Ans. is 'c' i.e., Absence of definitive evidence of infection * It is worth noting that Sepsis is the systemic response to infection and is defined as the presence of SIRS in addition to a documented infection.Definitions of sepsis, SIRS, severe sepsis, septic shockSystemic inflammatory response syndrome (SIRS): Clinically recognized by the prescence of two or more of the following temperature > 30deg or < 36degCHeart rate > 90 beats/minRespiratory rate > 20 breaths/min or PaCO2 < 32 mmHgWBC > 12,000 cells/min3> < 4000 cells/min3, or > 10% immature (band) formsSepsis: systemic response to infection. Thus the clinical signs decribing SIRS are present, together with definitive evidence of infection.Severe sepsis: Severe when it is associated with organ dysfunction, hypoperfusion, or hypotension. The manifestations of hypoperfusion may include, but are not limited to, lactic acidosis, oliguria, or acute alteration in mental status.Septic shock : Sepsis with hypotension despite adequate fluid resuscitation combined with perfusion abnormalities that may include, but are not limited to, lactic acitosis, oliguria, or acute alteration in mental status. Patients who are on inotropic or vasopressor agents may not hypotensive at the time perfusion abnormalities are measure.Hypotension : Systolic blood pressure of >90 mmHg or a reduction of > 40 mgHg from baseline in the absence of other causes for the fall in blood pressure.