P36 Procalcitonin as an antimicrobial stewardship tool in the COVID-19 era: a single centre experience

Abstract

BackgroundProcalcitonin (PCT) is a biomarker which may have greater specificity than other pro-inflammatory markers in identifying bacterial infection and may aid in antimicrobial stewardship in COVID-19 patients.MethodsA PCT assay by Abbott diagnostics was introduced in our hospital in November 2020. Over a 12 week period, we prospectively recorded all PCT results on in-patients with COVID-19 admitted to the ICU, as well as stewardship actions taken following discussion with the ICU physicians. Microbiology records were reviewed to ascertain whether bacterial infection was subsequently confirmed.ResultsSixty-four PCT results were recorded on 27 patients (Table 1). Antimicrobials were discontinued on 12 occasions and withheld on 16 occasions where PCT was <0.5 ng/mL. No cases of confirmed bacterial infection were diagnosed in patients with PCT concentrations of <0.05 ng/mL; however definite bacterial infection was confirmed in two patients (one case of Staphylococcus aureus bloodstream infection; one case of Staphylococcus epidermidis CVC infection), and bacterial infection was designated probable in five patients with PCT ≥0.05 ng/mL and <0.5 ng/mL.Table 1.PCT resultsResultInterpretationNo. of samples<0.05 ng/mLAbsence of bacterial infection4≥0.05 ng/mL and <0.5 ng/mLSystemic bacterial infection is not likely41≥0.5 ng/mL and <2 ng/mLSystemic bacterial infection is possible12≥2 ng/mL and <10 ng/mLSystemic bacterial infection is likely5≥10 ng/mLSystemic bacterial is highly likely2ConclusionsPCT may be a useful tool in enabling antimicrobial stewardship actions in patients with severe COVID-19, but results need to be interpreted within the clinical context.