Catheter-Associated Bloodstream Infection Incidence and Risk Factors in Adults with Cancer: A Prospective Cohort Study.

Central venous catheter-associated blood stream infections (CA-BSI) cause considerable morbidity in adult patients with hematologic cancers and solid tumors. A range of central venous access devices (CVAD) may be used across differing patient diagnoses and for varying indications. The aim of our study was to determine the incidence and risk factors for CA-BSI.

A prospective observational cohort study of consecutive adult patients requiring a CVAD in a hematology-oncology unit (including autologous but not allogeneic transplantation) was performed. All CVADs were inserted under ultrasound guidance in a dedicated interventional radiology facility with peripherally inserted central venous catheters (PICCs) inserted in the basilic or cephalic vein and tunnelled lines, non-tunnelled lines and implantable ports inserted via the internal jugular vein. Standardized surveillance methods for CA-BSI were applied and data on CVAD complications were recorded.

1119 CVADs were assessed in 723 patients over 50,478 line days. Median patient age was 55yrs and 56% were male. Patient diagnoses included aggressive hematologic malignancies (48%, includes AML (17%), MDS (1%), NHL (22%) and MM (8%)), Hodgkin lymphoma (3%), other hematologic malignancies (3%), oesophageal/colon/rectal cancers (26%), and all other solid tumors (20%). CVAD types included PICCs (71%), non-tunnelled lines (14%), tunnelled lines (14%), and implantable ports (1%). 291 lines were removed due to a clinical suspicion of infection, 133 of these had CA-BSI and 34 of these had a positive tip culture in addition to meeting the definition of CA-BSI. The four most common bacterial isolates were S. epidermidis (n=23), S. aureus (n=15), Pseudomonas sp (n=12) and Stenotrophomonas sp (n=10). The rate of CA-BSI per 1,000 line days was 2.63. In multivariate analysis, factors associated with CA-BSI included: type of CVAD (greatest for non-tunnelled lines (HR 3.67, p<0.0001) and tunnelled lines (HR 1.83, p=0.0062) compared to PICC lines); patient diagnosis (greatest for aggressive haematological malignancies (HR 2.95, p=0.0031) and least for oesophageal, colon and rectal cancers (HR 0.26, p=0.014) compared to other solid tumours); side of insertion (greatest for right-sided lines (HR 1.61, p=0.024)); and number or prior line insertions (HR1.2, p=0.016). In a subgroup analysis of patients with aggressive hematologic malignancies, the association between CA-BSI and line type (greater infection for tunnelled (HR 1.46, p=0.09) and non-tunnelled lines (HR 3.73, p<0.001) compared to PICCs) and side of line insertion (more infection with right sided lines (HR1.66, p=0.035)) remained. 4.8% of lines were complicated by symptomatic thrombosis which was less common in patients with oesophageal, colon and rectal cancer (HR 0.43, p=0.027) and in lines inserted in the internal jugular vein (HR 0.2, p=0.0083) compared to PICC lines.

Incidence of CA-BSI in an Australian adult cancer population is comparable to other reports in the literature. This study highlights the utility of a standardised CA-BSI surveillance strategy in adult patients with cancer, provides further data to support the use of PICC lines in such patient populations, including patients with hematological malignancies, and suggests that the side of line insertion may influence CA-BSI.

No relevant conflicts of interest to declare.