Diagnosis, prevention, and management of catheter related bloodstream infection during long term parenteral nutrition
- Department of Paediatrics, Leeds Teaching Hospitals NHS Trust, Leeds, UK
- Correspondence to:
Dr J W L Puntis, C Floor, Clarendon Wing, Leeds General Infirmary, Belmont Grove, Leeds LS2 9NS, UK;
puntisj{at}ulth.northy.nhs.uk
- AOLC, acridine orange leucocyte cytospin test
- CFU, colony forming unit
- CR-BSI, catheter related bloodstream infection
- CVC, central venous catheter
- PN, parenteral nutrition
Central venous catheter related bloodstream infection is an important cause of morbidity and mortality
Central venous catheters (CVC) are widely used in children receiving long term parenteral nutrition (PN). They provide secure venous access and allow safe administration of hypertonic solutions. However, catheter related bloodstream infection (CR-BSI) is a serious and potentially life threatening complication.1,2 Evidence based guidelines for the prevention of CR-BSI have recently been published by the Department of Health.3 These focus on hospital acquired infection in patients of 4 years and above, and do not address the important issues of diagnosis and treatment. The clinical features are often non-specific and up to 85% of those catheters removed on clinical grounds alone are subsequently proven to be sterile.4 The clinician suspecting CR-BSI is presented with a difficult dilemma given that CVC removal results in loss of venous access, while an infected catheter left in situ may lead to overwhelming sepsis. Until recently, standard techniques for diagnosing CR-BSI involved catheter removal. However, the development of novel diagnostic tests currently allows earlier and more accurate diagnosis with the CVC left in place. In addition, management of CR-BSI with through-catheter antibiotics has become accepted practice and can lead to a high proportion of infected catheters being successfully salvaged.5
PATHOGENESIS
Venous catheters may become colonised with bacteria after 24 hours of insertion, the outer surface with organisms originating from the skin at the time of placement, and the lumen usually later, from those entering the catheter hub during connection and disconnection. CVCs may also become infected as a result of haematological seeding from a distal site, and occasionally from contaminated infusate. Electron microscopy of CVCs reveals a biofilm adherent to the internal lumen, and a fibrin sheath, which forms extraluminally. Bacteria colonising the catheter lumen exist in two …
