Blood cultures are critical for the diagnosis of sepsis/severe sepsis. Blood cultures should be drawn prior to the administration of antibiotics.
Cultures take time to grow. This time can mean the difference between life and death for a patient. Although sepsis/severe sepsis cannot be definitively diagnosed until it is determined that there is a blood or tissue infection, the diagnosis may still be made if other criteria strongly suggests its presence. If the patient exhibits altered mental status and/or edema in addition to the SIRS criteria, or if one or more of the laboratory test results shown below are obtained along with evidence from the clinical assessment, the physician may choose to start antibiotic treatment before the results of the cultures are available:
- Elevated C-reactive protein (CRP)
- Elevated procalcitonin
- Elevated lactic acid (lactate)