At least one should be drawn through the skin and one through each vascular access device (such as an IV catheter) that has been in place more than 48 hours. Bacteria are present in the blood in only about 30% of cases. Another possible method of detection is by polymerase chain reaction. If other sources of infection are suspected, cultures of these sources, such as urine, cerebrospinal fluid, wounds, or respiratory secretions, also should be obtained, as long as this does not delay the use of antibiotics.Within six hours, if blood pressure remains low despite initial fluid resuscitation of 30 mL/kg, or if initial lactate is ≥ four mmol/L (36 mg/dL), central venous pressure and central venous oxygen saturation should be measured. Lactate should be re-measured if the initial lactate was elevated. Evidence for point of care lactate measurement over usual methods of measurement, however, is poor.Within twelve hours, it is essential to diagnose or exclude any source of infection that would require emergent source control, such as a necrotizing soft tissue infection, an infection causing inflammation of the abdominal cavity lining, an infection of the bile duct, or an intestinal infarction. A pierced internal organ (free air on an abdominal X-ray or CT scan), an abnormal chest X-ray consistent with pneumonia (with focal opacification), or petechiae, purpura, or purpura fulminans may indicate the presence of an infection. Definitions
Previously, SIRS criteria had been used to define sepsis.
Neonatal sepsis
In common clinical usage, neonatal sepsis refers to a bacterial blood stream infection in the first month of life, such as meningitis, pneumonia, pyelonephritis, or gastroenteritis, but neonatal sepsis also may be due to infection with fungi, viruses, or parasites. Criteria with regard to hemodynamic compromise or respiratory failure are not useful because they present too late for intervention. Management
Early recognition and focused management may improve the outcomes in sepsis. Current professional recommendations include a number of actions ("bundles") to be followed as soon as possible after diagnosis. Within the first three hours, someone with sepsis should have received antibiotics and, intravenous fluids if there is evidence of either low blood pressure or other evidence for inadequate blood supply to organs (as evidenced by a raised level of lactate); blood cultures also should be obtained within this time period. After six hours the blood pressure should be adequate, close monitoring of blood pressure and blood supply to organs should be in place, and the lactate should be measured again if initially it was raised. A related bundle, the "Sepsis Six", is in widespread use in the United Kingdom; this requires the administration of antibiotics within an hour of recognition, blood cultures, lactate, and hemoglobin determination, urine output monitoring, high-flow oxygen, and intravenous fluids.Apart from the timely administration of fluids and antibiotics, the management of sepsis also involves surgical drainage of infected fluid collections and appropriate support for organ dysfunction.