Central catheter blood sampling: the impact of changing the needleless caps prior to collection.

Little is known about the association between central catheter needleless connectors and bacteremia. In a cohort study on 91 patients, central catheter blood samples were collected using 3 methods--old cap (the existing cap), new cap (after replacing the old cap with a new sterile cap), and peripheral methods--from each patient and their correlation was examined. The old cap method identified 36 positive bacteremia cases. However, only 17 cases were verified by the new cap method, yielding a positive predictive value of 47.2% (17/36). The 19 false-positive cases indicated old cap contamination. This study recommends that changing the needleless cap before drawing blood samples would be an ideal practice for obtaining more specific and reliable results in diagnosing bacteremia.