An evaluation of blood cultures obtained via a central venous catheter

BACKGROUND: The aim of this study was to determine the use of blood samples obtained through central venous catheters (CVC) in the diagnosis of bacteremias in patients admitted to an intensive care unit (ICU). METHODS: A prospective randomized study was carried out in which 125 blood samples obtained by CVC were compared with 125 samples simultaneously obtained by venipuncture. RESULTS: In 105 sample pairs (84%) the results of both samples were in agreement (Kappa index 0.61). The sensitivity of the technique in the diagnosis of bacteremia was 76.5%, specificity 86.8% positive predictive value 68.4% and negative predictive value 90.8%. No differences were found in the efficacy of the technique carried out by venous punction or that of the samples obtained through catheters inserted in subclavian, femoral and antecubital veins (p = 0.99). CONCLUSIONS: Blood cultures obtained through central venous catheters constitute a technical alternative for the diagnosis of bacteremia in cases in which venipuncture is difficult or of doubtful asepsis.