Blood culture as a guide for the diagnosis of central venous catheter sepsis.

The purpose of this study was to evaluate the predictability of peripheral (PBC) and central blood cultures (CBC) in the diagnosis of central venous catheter (CVC) sepsis (growth of the same microorganism in the peripheral blood and on the catheter tip). The contamination and sepsis rate of 256 CVCs and the relationship with PBC and CBC was evaluated in a series of cancer patients included in a prospective protocol on CVC infections at the Istituto Nazionale Tumori of Milan. Overall CVC contamination was 10.5% and sepsis rate was 3.1%. The positive predictive value for CVC sepsis was 46.7% for positive PBC + CBC, 38.1% for positive PBC and 16.6% for positive CBC. The small gain in the predictive positive value obtained with the use of PBC and CBC and the slight increase in the specificity does not justify, in our opinion, the use of both these parameters for the diagnosis of CVC sepsis.