Earlier positivity of central-venous- versus peripheral-blood cultures is highly predictive of catheter-related sepsis

To diagnose catheter related sepsis without removing the catheter, we evaluated the differential positivity times of cultures of blood drawn simultaneously from central venous catheter and peripheral sites. In a 450-bed cancer reference center, simultaneous central-and peripheral-blood cultures were prospectively performed for patients with suspicion of catheter-related sepsis over an 18-month period. Data for 64 patients for whom the same microorganisms were found when central-and peripheral-blood samples were cultured were retrospectively reviewed by two independent physicians blinded to the differential positivity time values in order to establish or refute the diagnosis of catheter-related sepsis, The diagnosis was established in 28 cases, refuted in 14, and indeterminate in the remaining 22. The differential positivity time was significantly greater for patients with catheter-related sepsis (P < 10(-4)), A cutoff limit of +120 min had 100% specificity and 96.4% sensitivity for the diagnosis of catheter-related sepsis, These results strongly suggest that measurement of the differential positivity time might be a reliable tool facilitating the diagnosis of catheter-related sepsis in patients with an indwelling catheter.