Makindo Medical Notes

⚠️ Strict asepsis is essential: a skin contaminant (e.g. coagulase-negative staphylococci) can result in unnecessary prolonged antibiotics for a “false” bacteraemia. 👉 Think “contamination = complication.”

🧾 Introduction

• Blood cultures are a key part of the sepsis screen alongside urine culture, CXR, sputum culture and serology.
• Indications: fever, rigors, sweats, delirium, or other signs of sepsis. ⚠️ Some bacteraemic patients may be afebrile.
• Always send two bottles – one aerobic, one anaerobic. If volume limited, prioritise the aerobic bottle.
• Optimal yield with ≥20 mL blood; minimum 5 mL per bottle.
• Label bottles clearly (do not cover barcodes) and send urgently to lab. Peel off miniature barcode for patient notes.

🎯 Special Situations

• Oncology/Haematology patients often have central venous catheters (CVCs) or ports – send one set via the line and one peripherally.
• Suspected infective endocarditis: take at least 3 sets from different sites/times before starting antibiotics.
• The more sets taken, the higher the diagnostic yield.

🧪 Results & Interpretation

• Preliminary results take ≥24 hours; full sensitivities take longer.
• Microbiology may call if a culture flags positive.
• False positives are common – always correlate with clinical picture. Discuss with Microbiology/ID team before acting.

👋 Practical Steps

• Wash hands and use PPE. Ensure name badge visible.
• Confirm patient identity, explain procedure, and obtain consent.
• Position patient comfortably, apply tourniquet, and identify vein (often antecubital fossa or forearm).

🧰 Equipment

• Sterile gloves & apron.
• Tourniquet.
• Chlorhexidine/alcohol wipes (repeat cleansing up to 5 times if needed).
• Needle & syringe OR vacutainer system.
• Aerobic & anaerobic culture bottles.
• Gauze/cotton wool, plaster, sharps bin.

💉 Technique

• Disinfect chosen site with chlorhexidine/alcohol, let dry fully. Do not re-touch.
• Insert needle (~30° angle), confirm flashback, and draw blood.
• Inoculate bottles (anaerobic first if using a syringe; aerobic first if using vacutainer).
• Release tourniquet before removing needle to reduce bruising.
• Apply pressure, achieve haemostasis, dress site, thank patient.

🧾 Finally

• Dispose of sharps safely.
• Label bottles at bedside with patient identifiers.
• Document time, site, and number of sets taken.
• Answer patient questions and provide reassurance.

⚠️ Complications & Pitfalls

• Failure: after 2–3 attempts, seek senior help or come back later.
• Haematoma: usually from not releasing tourniquet before removing needle.
• Arterial puncture: bright red pulsatile blood – withdraw and apply firm pressure.
• Contamination: the most frequent “complication.” Scrupulous skin prep is the best prevention.

📚 Teaching Pearls

• Draw before antibiotics unless delay is unsafe.
• Mark “time of collection” – helps interpret line vs peripheral sepsis.
• False positives waste resources; false negatives can be fatal – balance urgency with precision.