[The risk factors associated with colonization and bacteremia in non-tunnelled central venous catheters]

To identify risk factors for colonization and bacteremia among patients with non-tunnelled central venous catheters.

A prospective study was conducted of a cohort of patients carrying non-tunnelled central venous catheters. Different parameters were obtained and the degree of its association with colonization of the distal portion of the catheter or with bacteremia associated with colonization was estimated. The CDC (centers for Disease Control) diagnostic criteria of colonization and catheter-related bacteremia were used.

A total of 118 catheters were eventually analyzed, corresponding to 114 patients, with a catheterization mean time of 14 +/- 8 days (mean +/- SD); out of these 114 patients, 51 were colonized and in 22 the presence of associated bacteremia was confirmed. The parameters associated with a higher risk for catheter colonization included length of colonization, femoral location, number of lumina and a vital prognosis lower than one month. All these factors, with the exception of the increase in the number of lumina, showed an independent association with colonization on the multivariate analysis [catheterization length (in weeks): OR 1.46; 95% CI: 1.0-2.11; femoral location: OR 3.73; 95% CI: 1.16-11.9; vital prognosis lower than one month: OR 12.7; 95% CI: 1.4-112.7]. As for risk for catheter-related bacteremia, the univariate analysis showed an association with catheterization length and a vital prognosis lower than one month; the latter was the only factor that maintained an independent association in the multivariate analysis (OR 5.75; 95% CI: 1.17-28.27).

The present study documents the relevance of prolonged catheterization as a consistent risk for colonization of non-tunnelled central venous catheters. This risk increases independently in canalization at femoral site and particularly among severely ill patients. The presence of these factors allows the identification of a high risk population for the development of catheter related bacteremia.