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Background Procalcitonin (PCT) can be elevated with certain bacterial infections. Debate continues as to how to best use this biomarker to guide antibiotic use. The primary objective of this study was to evaluate the correlation of PCT levels and the presence of bacterial infection on admission in the total population and in different disease states. Methods This was a multicenter retrospective cross-sectional study of patients admitted with specified infectious diagnoses to two VA Medical Centers from 4/1/2019 to 7/1/2021. Patients were stratified into 4 cohorts for analysis; those with COVID-19, sepsis from respiratory source_(S-R), sepsis from non-respiratory source (S-NR), and respiratory source without sepsis (R). Electronic medical records were reviewed to collect the following: initial procalcitonin, cultures, SIRS criteria, comorbidities (CKD, ESRD, HF, immunosuppressed, surgery within the 7 days), and c-reactive protein. PCT elevation was defined as ≥0.25 ng/mL. The frequency of positive cultures within 72 hours was evaluated for patients with elevated and normal PCT levels to determine the diagnostic performance of PCT overall and for each cohort. Results 632 of 664 patients were evaluated in this study. PCT is elevated twice as often in the septic groups as compared to the non-septic groups (figure 1). Positive predictive value (PPV) varies from 27% to 63% as compared to negative predictive value (NPV) 53%-79% among the disease state groups (figure 2). Although small numbers, the NPV of PCT improves to 83% in patients with elevated temperature and white blood cells (WBC) (figure 3). Figure 1Figure 2Figure 3 Conclusion The findings that NPV of PCT appears to be better than PPV, support current recommendations against using this as a diagnostic tool, but rather as a tool to assist with antibiotic de-escalation. Further studies are necessary to confirm whether there are specific markers such as temperature or WBC which may improve the NPV. Our data suggests PCT is less helpful in identifying the presence or absence of bacterial infection in septic versus non-septic patients. Disclosures All Authors: No reported disclosures.

Background Procalcitonin (PCT) is an inflammatory biomarker that can be helpful for early detection of certain types of infections and can be a useful tool to decrease unnecessary antibiotic (abx ) exposure. However, its use among clinicians remains variable. The aim of this study was to elucidate current practices at a selection of Veteran’s Administration medical centers. Methods The VISN-9 Antimicrobial Stewardship Collaborative distributed a 15-question survey electronically to providers at all five VA medical centers in VISN-9 between 1/15/22 to 3/31/22 to clinicians practicing in the acute care, ICU and ED settings. Information on level of training, primary site as well as current practices and beliefs about PCT were collected. Responses were tabulated as percentages for this cross-sectional study. Results 99 providers completed the survey with two centers comprising 83% of responses. 44% of respondents were attendings. The Figures illustrate some interesting variability in the use of PCT. Figure 1 reveals more than half of residents but less than a quarter of attendings ordered PCT on admission for patients with suspected infection. Figure 2 shows similar use of PCT by attendings and residents to initiate abx, however, residents used PCT much more than attendings to justify continuation of abx, and residents used PCT somewhat more than attendings to de-escalate abx. Only one clinician ordered PCT daily. Figure 3, ordering practices by disease state, shows similar trends between the two groups. 44% of all respondents felt somewhat comfortable whereas 22% felt somewhat uncomfortable interpreting PCT results. Some of the interesting comments from respondents included: “PCT is “ordered too often and indiscriminately”; “I never know what to do with it”; and “I usually allow my patients to complete their abx courses rather than discontinuing abx earlier”. Conclusion Using PCT to help guide abx use can help minimize unnecessary abx exposure which may help to stem the increase in antimicrobial resistance. This survey indicates that many clinicians are unsure of when to use PCT, how often to order it, and whether it is a reliable enough tool on which to base treatment decisions. Further education will be necessary to help inform best practices. Disclosures All Authors: No reported disclosures.