What is known and objective: Procalcitonin (PCT) levels rise in systemic inflammation, especially if bacterial in origin. COVID-19, caused by the novel coronavirus SARS-CoV-2, presents with acute respiratory distress syndrome. Elevated procalcitonin in COVID-19 is considered as a marker for severity of disease. There is no study available that indicates whether elevated PCT in COVID-19 is associated with inflammation or superimposed bacterial infection. The objective of this study is to evaluate the association between PCT levels and superadded bacterial infection, and the effect of discontinuation of antibiotic in the low PCT (<0.25 ng/ml) group on patients' outcomes.
Methods: A retrospective chart review of patients admitted with COVID-19 pneumonia at a single tertiary care centre. We collected information on demographics, co-morbidities, PCT level, antibiotic use, culture results for bacterial infection, hospital length of stay (LOS) and mortality.
Statistical analysis: Continuous variables were summarized with the sample median, interquartile range, mean and range. Categorical variables were summarized with number and percentage of patients.
Results and discussion: We studied a total of 147 patients with COVID-19 pneumonia. 101 (69%) patients had a low PCT level (< 0.25 ng/ml). Bacterial culture results were negative for all patients, except 1 who had a markedly elevated PCT level (141.ng/ml). In patients with low PCT, 42% received no antibiotics, 59% received antibiotics initially, 32 (57%) patients antibiotic discontinued early (within 24 hours) and their culture remained negative for bacterial infections during hospitalizations. LOS was shorter (6 days in low PCT group compared to 9 days) in high PCT group. LOS was 1 day shorter (5 days vs 6 days) in no antibiotic group compared to antibiotic group. Our study examines the association between PCT level and superadded bacterial infection in COVID-19 pneumonia. Our results demonstrate that most patients admitted with COVID-19 have a low PCT (<0.25 ng/ml), which suggests no superadded bacterial infection and supports the previously published literature regarding low PCT in viral pneumonia.
What is new and conclusion: Procalcitonin level remains low in the absence of bacterial infection. Early de-escalation/discontinuation of antibiotics is safe without adverse outcomes in COVID-19 pneumonia. Early de-escalation/discontinuation of antibiotics is associated with lower LOS.
Keywords: COVID-19 pneumonia; antibiotic stewardship; procalcitonin.
© 2021 John Wiley & Sons Ltd.