Bloodstream infections/sepsis

Bloodstream infections/sepsis are caused by pathogens entering the bloodstream (seen in infections such as HAP/VAP and cUTI). It is a systemic response which has met the clinical criteria of systemic inflammatory response syndrome (SIRS), with an identified site of infection (e.g. intra-abdominal infection) that is caused by carbapenem-resistant (CR) gram negative bacteria.

The inclusion criteria for bloodstream infections are as follows:

• Patients have symptoms associated with bacteraemia

• Patients have one or more positive blood cultures detecting a CR gram negative bacteria that is consistent with the patient’s condition

The inclusion criteria for sepsis are:

• Patients have two or more of the following which defines SIRS:

  • Oral or tympanic body temperature >38°C or <36°C

  • WBC >12,000 cells/mm³, 10% immature (band) forms

  • Tachycardia (heart rate >90 bpm)

  • Tachypnoea (manifests as a respiratory rate >20 breaths per minute or hyperventilation, as indicated by an arterial partial pressure of carbon dioxide (PaCO2) of <32 mmHg)

  • A CR gram negative bacteria has been isolated from an identified infection site from the patient

Most notably of the NFGNB, Pseudomonas, Acinetobacter and Stenotrophomonas species are most frequently associated with bloodstream infections and sepsis.

Similarly to other case studies, the antibiotics used to treat bloodstream infections and sepsis depends on the species of pathogen that has been isolated as well as a number of other factors, including the original site (organ) of infection. Initially broad-spectrum antibiotics are given (often carbapenem with fluoroquinolones or aminoglycosides), but these may be decreased or changed depending on the specific microbe that has been identified.