Blood Specimen Collection from a PICC Line
Clean the catheter hub meticulously with alcoholic chlorhexidine (>0.5%), alcohol, or tincture of iodine, allow adequate drying time, then draw the blood specimen directly from the PICC hub using sterile technique. 1
Step-by-Step Procedure
1. Preparation Before Drawing Blood
- Perform hand hygiene and gather sterile supplies before approaching the patient 1
- Identify which PICC lumen to use if the catheter is multi-lumen (preferably the lumen used for parenteral nutrition or blood products if drawing cultures) 2
- Do not draw blood cultures routinely from PICCs unless specifically evaluating for catheter-related bloodstream infection (CRBSI) 1
2. Hub Disinfection (Critical Step)
- Apply alcoholic chlorhexidine (>0.5%), alcohol, or tincture of iodine to the catheter hub 1
- Allow adequate contact and drying time (approximately 30 seconds for chlorhexidine or iodine tincture) before accessing the hub 3
- Avoid povidone-iodine as it requires 1.5-2 minutes to exert antiseptic effect compared to 30 seconds for chlorhexidine 3
3. Blood Draw Technique
- Access the hub using sterile technique after the antiseptic has dried 1
- Discard the first 5-10 mL of blood to clear the catheter of any flush solution or medications (standard practice, though not explicitly detailed in infection guidelines)
- Collect the required blood volume for your intended tests 4
- Flush the PICC line appropriately after specimen collection per institutional protocol
Special Considerations for Blood Cultures
When CRBSI is Suspected
- Draw paired blood samples simultaneously: one from the PICC hub and one from a peripheral vein before starting antibiotics 1, 2
- Label bottles clearly to indicate which site each sample came from (PICC vs. peripheral) 1, 2
- This paired approach allows diagnostic confirmation through quantitative comparison (colony count from catheter ≥3-fold greater than peripheral) or differential time to positivity (catheter blood positive ≥2 hours before peripheral) 2, 5
When Peripheral Access is Unavailable
- Draw blood cultures from at least 2 different PICC lumens if the catheter is multi-lumen and peripheral access cannot be obtained 1, 2
- Do not routinely culture all lumens as standard practice, as evidence does not support this and it increases cost without proven benefit 2, 3
Critical Pitfalls to Avoid
- Never skip hub disinfection or rush the drying time, as this dramatically increases contamination rates and false-positive blood cultures 1, 3
- Do not use blood drawn from PICCs for routine laboratory work when peripheral venipuncture is feasible, as peripheral blood is the gold standard and less likely to be contaminated 3, 5
- Avoid drawing blood cultures from PICCs unless specifically evaluating for CRBSI, as catheter-drawn cultures have higher contamination rates than peripheral venipuncture 1, 5
- Ensure adequate blood volume is collected, as volume is the most important variable in recovering organisms from bloodstream infections 3
Clinical Context
PICCs are increasingly used for long-term intravenous access, including for chemotherapy, antibiotics, parenteral nutrition, and blood sampling 4, 6. While they provide convenient access, the infection risk (2.2-4.9% catheter-related infection rate) necessitates meticulous sterile technique when accessing these lines 7, 8. The hub is a critical point of microbial entry, particularly for long-term catheters (≥14 days), where intraluminal spread from the hub is the predominant mechanism of infection 1.