In patients with suspected sepsis or septic shock, appropriate routine microbiologic cultures should be obtained before initiation of antimicrobial therapy from all potential sites of infection. These may include blood, respiratory secretions, urine, cerebrospinal fluid, wounds, and other body fluids. If it is not logistically possible to obtain cultures promptly (45 minutes), the appropriate antimicrobials should be administered.

In sepsis or septic shock patients, the diagnosis includes identification of a specific anatomic site of infection requiring emergent source control.