Colonization of the medial lumen is a risk factor for catheter-related bloodstream infection.

OBJECTIVE: To analyze the colonization of each lumen and the risk factors for triple-lumen central venous catheter-related bloodstream infection (CRBI). DESIGN AND SETTING: Prospective, observational study in the medical-surgical intensive care unit (ICU) of a teaching hospital. PATIENTS: A total of 120 patients requiring the insertion of a triple-lumen catheter. INTERVENTIONS: Cultures of the catheter. MEASUREMENTS AND RESULTS: The catheters were removed when CRBI was suspected or at discharge from ICU. At the removal time, blood cultures, a swab of the insertion site and a culture of the catheter tip were performed. Furthermore, we made quantitative cultures of the proximal, medial and distal lumen. We diagnosed CRBI in six patients (3.35 CRBI/1,000 days at risk), and we observed that in these patients colonization of the medial lumen was more frequent (5/6) than in patients without CRBI (9/114; p = 0.0001). The logistic regression analysis showed that colonization of the medial lumen was an independent risk factor for CRBI (OR 28.1, 95% CI 2.2-364.9). CONCLUSIONS: Colonization of the medial lumen is an independent risk factor for triple-lumen catheter-related bloodstream infection, possibly due to the absence of use of this lumen.