Central venous catheter-associated bloodstream infection and colonisation of insertion site and catheter tip. What are the rates and risk factors in haematology patients?

Skin colonisation is an important source for central venous catheter (CVC) colonisation and infection. This study intended to identify risk factors for skin colonisation prior to CVC placement (baseline colonisation) and within 10 days after CVC insertion (subsequent colonisation), for CVC-tip colonisation and for bloodstream infection (BSI). Within a randomised clinical trial, data of 219 patients with haematological malignancies and inserted CVC (with a total of 5,501 CVC-days and 4,275 days at risk) in two university hospitals were analysed. Quantitative skin cultures were obtained from the insertion site before CVC placement and at regular intervals afterwards. CVC-tip cultures were taken on CVC removal and data collection was performed. Statistical analysis included linear and logistic regression models. Age was an independent risk factor for colonisation prior to CVC placement (baseline colonisation). Independent risk factors for subsequent colonisation were baseline colonisation and male gender. High level of subsequent skin colonisation at the insertion site was a predictor of CVC-tip colonisation, and a predictor of BSI. High level of skin colonisation predicts catheter tip colonisation and possibly subsequent infection. Sustained reduction of bacterial growth at the CVC insertion site is therefore indispensable. Male patients are at particular risk for skin colonisation and may be a target population for additional insertion-site care before and during catheterisation.