Diagnostic yield of bacteriological tests and predictors of severe outcome in adult patients with COVID-19 presenting to the emergency department

Abstract

BackgroundGuidelines recommend maximal efforts to obtain blood and sputum cultures in patients with COVID-19, as bacterial coinfection is associated with worse outcomes. The aim of this study was to evaluate the yield of bacteriological tests, including blood and sputum cultures, and the association of multiple biomarkers and the Pneumonia Severity Index (PSI) with clinical and microbiological outcomes in patients with COVID-19 presenting to the emergency department (ED).MethodsThis is a substudy of a large observational cohort study (PredictED study). The PredictED included adult patients from whom a blood culture was drawn at the ED of Haga Teaching Hospital, The Netherlands. For this substudy, all patients who tested positive for SARS-CoV-2 by PCR in March and April 2020 were included. The primary outcome was the incidence of bacterial coinfection. We used logistic regression analysis for associations of procalcitonin, C reactive protein (CRP), ferritin, lymphocyte count and PSI score with a severe disease course, defined as intensive care unit admission and/or 30-day mortality. The area under the receiver operating characteristics curve (AUC) quantified the discriminatory performance.ResultsWe included 142 SARS-CoV-2 positive patients. On presentation, the median duration of symptoms was 8 days. 41 (29%) patients had a severe disease course and 24 (17%) died within 30 days. The incidence of bacterial coinfection was 2/142 (1.4%). None of the blood cultures showed pathogen growth while 6.3% was contaminated. The AUCs for predicting severe disease were 0.76 (95% CI 0.68 to 0.84), 0.70 (0.61 to 0.79), 0.62 (0.51 to 0.74), 0.62 (0.51 to 0.72) and 0.72 (0.63 to 0.81) for procalcitonin, CRP, ferritin, lymphocyte count and PSI score, respectively.ConclusionBlood cultures appear to have limited value while procalcitonin and the PSI appear to be promising tools in helping physicians identify patients at risk for severe disease course in COVID-19 at presentation to the ED.

High procalcitonin levels associated with increased intensive care unit admission and mortality in patients with a COVID-19 infection in the emergency department

“…Surme et al investigated predictors of ICU admission and mortality and also found that high PCT were associated with an increase of the composite outcome of ICU admission and mortality [ 19 ]. Kaal et al also showed similar results in a cohort of 142 patients, and showed that patients with PCT levels above 0.1 ng/mL have an elevated risk of a severe infection [ 20 ].…”

Platelet‐derived immuno‐inflammatory indices show best performance in early prediction of COVID‐19 progression

“… 4 , 5 , 6 , 7 There was a nearly threefold increased risk of severe COVID‐19 with a lymphocyte count <1.5 x 10 9 /L. 7 However, certain studies failed to determine any significant correlations between absolute lymphocyte count and severe disease, such as the study by Kaal et al 26 We found lower lymphocyte counts in patients who experienced disease progression and death; however, the results were without statistical significance. The result is evidently a consequence of commonly present lymphopenia in most of our patients at admission (median 0.980 x 10 9 /L).…”

Serum Procalcitonin as a Predictive Biomarker in COVID-19: A Retrospective Cohort Analysis

“…Carbonell et al concluded that elevated procalcitonin level at admission was associated with higher mortality, independent of the possible bacterial co-infection [18]. Surme et al found that high procalcitonin levels were associated with worse outcomes and higher mortality in ICU patients [19]. Tong-Minh et al showed a higher rate of ICU admission and mortality in patients with higher procalcitonin levels in the emergency department [20].…”