(567) Association of Central Venous Catheter Occlusions and Bloodstream Infections: A Retrospective Study

Introduction: Central venous catheters (CVC) are often used in the intensive care unit but can be associated with complications, including infections. Central line-associated bloodstream infections (CLABSIs) are linked to increased ICU length of stay, mortality rates, and costs. Prior literature suggests a link between CVC thrombosis and infection. Our retrospective study compares infection rates between occluded and non-occluded central lines to identify an increased risk of CLABSIs.

Methods: We conducted a retrospective review of the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Our inclusion criteria were patients admitted to an ICU of any type with placement of a CVC and positive blood cultures during the presence of this CVC. The cohorts were separated by occluded versus non-occluded catheters, identified by the need for clearance dose of alteplase (TPA).

Results: 15,244 CVCs were analyzed, with 203 (1.3%) occluded catheters. 20/203 (9.8%) developed positive blood cultures, compared to 714/15,041 (4.7%) in the non-occluded group. The odds ratio for developing a positive blood culture was 2.19 times higher in the occluded group (p-value < 0.001). Among those who developed positive cultures, 11/20 (55%) had line occlusions prior with 8/11 (73%) developing positive cultures within 5 days of requiring TPA. Our study also found that 9/20 (45%) individuals developed line occlusions after having positive blood cultures. 8/9 (89%) developed line occlusions within 3 days of having positive blood cultures.

Conclusions: Our study shows a significant association between occluded catheters and positive blood cultures suggesting that occlusion of a CVC may be used as a surrogate risk factor for impending bloodstream infection. Previous studies have discussed how bacteria can adhere to the fibrin sheath of a CVC and promote thrombogenesis. Others have found that clots may serve as a nidus for infection. Thus, more investigation is required to determine whether occlusion indicates that the CVC already has bacteria or whether the occlusion may increase the risk of future infection. Additional studies are needed to clarify whether early line removal is indicated for patients with catheter occlusions.