Blood Stream Infections

Initial Management of Newly Positive Blood Cultures (Stage 1)

Positive blood cultures with likely pathogens are phoned to the relevant clinical team by the laboratory and followed up by a consultant microbiologist Mon - Fri 09.00-17.00, including Public Holidays.

Out of hours (17.00 – 09.00) and at weekends, the laboratory will contact a nominated member of the specialties’ on call teams. See Quick Reference Guide: Positive Blood Culture Notification (Out-of-Hours) - link only active if accessing via NHS network.

• Every patient with a new positive blood culture requires clinical review. Seek urgent senior clinical review for patients with NEWS 2 score ≥7 and ensure appropriate antimicrobial therapy is given in a timely manner.
• The following flowcharts replace immediate microbiology consultations and guides initial management in the absence of the microbiology out-of-hours service. Staphylococci/streptococci differentiation can be challenging in microscopy; consult both flowcharts when needed. Refer to appendix 1 in the main ADTC guideline on the Initial Management of Positive Blood Cultures in Adults ≥16years old: A Guideline for Doctors and Advanced Nurse Practitioners (link only active if accessing via NHS network) for pathogen details.
• Where the need for possible additional antimicrobial agents is mentioned in the flowchart, please refer to the NHS Ayrshire & Arran empirical antimicrobial guidance, taking previous culture results into account.
• Results likely to represent contamination (e.g. coagulase negative staphylococci, diphteroids) are not phoned routinely.
• All new positive blood cultures are reviewed by a consultant microbiologist Mon-Fri 09.00-17.00, who will prioritise review of urgent cases (e.g. likely ineffective current treatment, endocarditis, notifiable diseases). Patients on appropriate treatment may be reviewed at a later stage.

The four management flowcharts are:

• Gram positive cocci - staphylococci
• Gram positive cocci - streptococci
• Gram negative bacilli
• Yeasts

Refer to the main ADTC guideline on the Initial Management of Positive Blood Cultures in Adults ≥16years old: A Guideline for Doctors and Advanced Nurse Practitioners (link only active if accessing via NHS network) for further information on:

• blood culture processing,
• reporting timelines,
• result interpretation, and
• requesting additional microbiology input.

Managing positive blood cultures using provisional and final microbiology reports (stages 2 and 3)

Newly positive blood cultures need active follow-up by the clinical team at stages 2 (12-24 hours) and 3 (24-48 hours) to review new information and assess whether changes in treatment are required.

There will be no further phone calls from the laboratory to notify the team when updated results become available.

Refer to the full ADTC guideline when the microbiology on call service is not available: Management of positive blood cultures in adults ≥16 years old using provisional and final microbiology reports (stages 2 and 3) - interim guidance (link only active if accessing via NHS network).