NEGATIVE CATHETER-TIP CULTURE AND DIAGNOSIS OF CATHETER-RELATED BACTEREMIA

The accuracy of Paired quantitative blood cultures (PQtBCs) collected in pediatric Isolator 1.5-ml tubes compared to central venous catheter (CVC) segment cultures (hub and tip) to diagnose catheter-related bac teremia (CRB) was evaluated in 58 bacteremic adult patients. The secon d aim of this study was to state precisely whether the tip or the hub (or both) of the infected device was the source of the bacteremia in c ase of significant results of PQtBC. Fifty-eight bacteremic patients w ith suspected CRB entered the study. In 52 patients, the diagnosis was obtained before CVC removal by PQtBC and was confirmed by CVC segment cultures: CRB in 30 patients, non-catheter-related bacteremia in 22 p atients. Six patients had CRB not found by PQtBC. 1) PQtBC is 83% sens itive, 100% specific (negative predictive values 78%, positive predict ive values 100%). 2) Sixteen bacteremic patients had authentic hub-rel ated bacteremia (positive hub culture associated with negative tip cul tures). When CRB is suspected in bacteremic patients, a negative tip c ulture cannot exclude the diagnosis of CRB. In all cases, CVC tip cult ure must be associated either with PQtBC or with hub cultures.