Severe sepsis refers to sepsis-induced tissue hypoperfusion or organ dysfunction with any of the following thought to be due to the infection.
- Sepsis-induced hypotension
- Serum Lactate levels above upper limits of laboratory normal
- Urine output < 0.5 mL/kg/hr for more than two hours inspite of adequate fluid resuscitation
- Acute lung injury with PaO 2 /FIO 2 < 250 in the absence of pneumonia as infection source
- Acute lung injury with PaO 2 /FIO 2 < 200 in the presence of pneumonia as infection source
- Creatinine > 2 mg/dL
- Bilirubin > 2 mg/dL
- Platelet count < 100,000 microL –1
- Coagulopathy (INR > 1.5)
Sepsis-induced hypotension is defined as a systolic blood pressure (SBP) < 90 mmHg or mean arterial pressure (MAP) < 70 mmHg or a SBP decrease > 40 mmHg or less than two standard deviations below normal for age in the absence of other causes of hypotension.
Components of Sepsis-induced tissue hypoperfusion are
- Infection-induced hypotension
- Elevated lactate
- Oliguria.
Septic shock - Septic shock is defined as sepsis-induced hypotension persisting despite adequate fluid resuscitation, which may be defined as infusion of 30 mL/kg of crystalloids Septic shock is due to marked reduction in systemic vascular resistance, this is often associated with an increase in cardiac output.
