Significant blood stream infections will be followed up the next day by a Consultant Microbiologist, either by telephone or in person; they will discuss a treatment plan with the clinical team.
RAST (rapid antimicrobial susceptibility testing): Blood cultures that are newly positive before 12.00 now have identification and limited susceptibilities available on the same day, and a full report on the next day. In these circumstances, the following comment on reports will be seen: "This positive blood culture is suitable for rapid testing. A further report will be available between 8pm and 9pm this evening."
Four management algorithms are available (see here), divided into:
It can sometimes be difficult to differentiate gram positive cocci into staphylococci or streptococci on microscopy. In such situations, please refer to both flowcharts.
A Consultant Microbiologist is available for advice (see Appendix 6 for contact details) if recommended antimicrobials are inappropriate for the patient or if the management of the patient remains unclear.
Follow the Scottish Antimicrobial Prescribing Group (SAPG) algorithm for the treatment of suspected or proven SAB.
All cases of proven SAB are followed up by a consultant microbiologist, and a management plan will be communicated to the patient's clinical team.
S. aureus bacteraemia can occur in the context of a variety of infections with S. aureus, such as:
In turn, SAB can lead to serious metastatic infections, including:
SAB is associated with a mortality of up to 30%, and recurrence is seen in approximately 10% of cases.
Blood stream infections with candida species are a significant event that is associated with a mortality of up to 47%; if the patient presents with septic shock mortality rates are even higher.
Patients with significant comorbidities and who have received (prolonged) broad spectrum antimicrobials are at particular risk of candidaemia.
Mortality is closely linked to timing of therapy and source control - the earlier appropriate therapy is started and implicated foreign material, such as central venous access catheters are removed or infected collections are drained, the better the chances of survival.
If candida is isolated from a blood culture, this should not be regarded as a contaminant.
A consultant microbiologist will follow up all cases of candidaemia and advise on specific antifungal therapy and other aspects of management.
Remove all central venous catheters in non-neutropenic patients.
All patients should be referred to ophthalmology for funduscopic examination - candida endophthalmitis is a sight-threatening complication of candidaemia.
Patients should be treated for at least 14 days from the next negative blood culture - longer therapy may be required depending on the source and possible complications.
Patients with persistent candidaemia and those with prosthetic heart valves should have an echocardiogram to rule out infective endocarditis.
For further information, refer to this IDSA guideline.
Blood stream infections with gram negative bacilli/rods are often associated with intra-abdominal or urinary tract infections, although other sources are possible (e.g. vascular access device, hospital-acquired pneumonia); the most commonly isolated organism is Escherichia coli.
The initial treatment should be with an intravenous antimicrobial.
Please note that almost 70% of E. coli isolated from blood cultures in NHS Ayrshire & Arran are resistant to amoxicillin - this agent is only recommended for treatment if amoxicillin susceptibility has been confirmed.
Gentamicin should be avoided in patients with decompensated liver disease (jaundice, ascites, encephalopathy, variceal bleeding or hepato-renal syndrome).
| Condition | Samples to send | Comments |
|
Suspected peripheral vascular catheter (PVC) site infection |
|
Remove PVC if infection is suspected |
|
Suspected central vascular access device infection |
|
Differential time to positivity can help establishing whether source of bacteraemia is the access device, or whether a systemic bacteraemia from another source is present |
Page last updated: February 2024