Arterial lines, especially in Cardiac Intensive Care Units (CICU) are important in
caring for patients. While not central lines, blood cultures are often drawn from
them, potentially leading to contamination and over-diagnosis of central line-associated
bloodstream infections (CLABSI). Diagnostic stewardship is needed to ensure that correct
cultures are obtained, increase the identification of true-positive bacteremia, reduce
contamination, and eliminate false-positive CLABSIs.
A retrospective review was performed to determine effects of a clinical work pathway
(CWP) on blood culture practices and CLABSI rates in a 12-bed pediatric CICU from
August 1st, 2019, to July 31, 2021. A multidisciplinary and multi-unit team developed
a blood culture pathway in August 2020 discouraging culturing of often colonized arterial
lines in favor of peripheral venous draws. The primary outcome was the total number
of arterial line cultures collected per 100 patient-days. The secondary outcomes were
the National Healthcare Safety Network standardized infection ratio (SIR) for the
unit and the CLABSI rate per 1000 device-days.
In the pre-intervention period, 763 blood culture were sent over 4316 patient days.
For the post-intervention period, 632 cultures were sent over 5151 patient days. CICU
had 981 additional device days in the post-period as compared to the pre-intervention
period. Arterial line cultures decreased significantly from 3.99 arterial line cultures/100
patient days to 0.29 cultures/100 patient days (p< 0.001). The SIR went from 2.428
to 2.107 between the pre- and post-implementation period. The CLABSI rate decreased
from 3.13 infections/1000 device days to 2.71 infections/1000 device days.
Standardization of blood cultures in the CICU decreased the number of arterial line
cultures and contributed to a reduction in the SIR and CLABSI rate. The impact of
the COVID-19 pandemic on blood culture practices is unclear although higher patient
acuity was evident by the increase in device days post implementation of the CWP.