Blood Cultures 🧫
Guide for taking blood cultures. When to take, technique, sterile procedure, and interpretation for infection workup.
🧠 When to Take Blood Cultures
- Patient has a temperature >38°C or <36°C
- Signs of systemic infection or sepsis
- New hypotension, tachycardia or confusion
- Before commencing IV antibiotics (ideally)
- Suspicion of line-associated infections or endocarditis
🧾 Preparation
- Wash hands and don appropriate PPE
- Explain the procedure to the patient and perform positive patient identification
- Ensure correct blood culture bottles (aerobic + anaerobic)
- Butterfly needle or vacutainer system preferred
- Gauze, alcohol wipes, tourniquet, and sterile gloves ready
- Clean tops of bottles with alcohol wipe and allow to dry
💉 Collection Steps
- Use aseptic technique throughout
- Collect from two separate sites ideally
- Use fresh venepuncture site (not from a cannula)
- Draw aerobic bottle first if using a butterfly needle, otherwise order doesn’t matter
- Minimum 8-10ml per bottle
📦 After Collection
- Ensure bottles are labelled and request form completed
- Send to lab promptly (don’t refrigerate)
- Document in the notes: time, site, indication
- Start empiric antibiotics immediately after (if indicated)
⚠️ Important Considerations
- Avoid contamination – strict asepsis is vital
- Note if patient has a line/device (specify site)
- Note any recent antibiotic administration
- Indicate if investigating for endocarditis or fungal infection