Diagnosis and Management of Catheter-Related Bloodstream Infections

Diagnostic Criteria

• The Infectious Diseases Society of America (IDSA) recommends paired blood cultures from the catheter and a peripheral vein, collected simultaneously, to evaluate for catheter-related bloodstream infection (CRBSI) 1
• A diagnosis of CRBSI can be made when the same microorganism is found in at least one peripheral blood culture and in the culture of the catheter tip, with a sensitivity of 80-94% and specificity of 91-99% 1
• The differential time to positivity (DTP) criteria of ≥120 minutes or quantitative cultures with a colony count at least 3 times higher in the catheter can be used to diagnose CRBSI, with a sensitivity of 94% and specificity of 71% 1

Blood Culture Collection

• If peripheral blood samples cannot be obtained, the Society for Healthcare Epidemiology of America recommends obtaining ≥2 blood samples through different catheter lumens 1
• When peripheral access is impossible, cultures from two different catheter lumens at different times is an acceptable alternative, as recommended by the European Society for Medical Oncology 2
• Blood cultures should be obtained before starting antimicrobial therapy, as recommended by the IDSA and the European Society for Medical Oncology 1, 2

Skin Preparation and Antimicrobial Therapy

• The Society of Critical Care Medicine recommends using 2% chlorhexidine gluconate in 70% isopropyl alcohol or tincture of iodine for skin preparation 3
• Alcohol, iodine tincture, or alcoholic chlorhexidine (>0.5%) should be used rather than povidone-iodine, as recommended by the European Society for Medical Oncology 2
• Antimicrobial administration should not be delayed due to culture collection (ideally within 45 minutes), as suggested by the Critical Care Medicine guidelines 4

Blood Culture Timing and Frequency

• For suspected CRBSI, the Society of Critical Care Medicine recommends obtaining 3-4 blood cultures within the first 24 hours of fever onset 3
• The following table summarizes the diagnostic methods for CRBSI:

1

• Paired blood cultures should be obtained simultaneously (catheter and peripheral vein) and the skin and catheter connector should be prepared with alcohol, chlorhexidine alcohol (>0.5%), or iodine tincture, allowing adequate drying time, as recommended by the IDSA 1
• Contamination rates are higher in samples obtained through catheters in use compared to peripheral blood samples, according to the IDSA 1