Blood culture and profile of inflammatory biomarkers among COVID-19 patients in an intensive care unit of a tertiary care hospital

Abstract

Introduction and Aim: This is a retrospective study to analyse the pathogens causing bacteraemia in COVID-19 patients and its correlation with inflammatory biomarkers such as procalcitonin (PCT), C-reactive protein (CRP), total WBC counts (TC) and D-dimer. The objectives of this study were to evaluate the blood culture positivity rate, to identify the pathogens causing bacteraemia, to analyse their antibiogram and to assess the significance of inflammatory markers along with patient outcomes.   Materials and Methods: This study included 165 COVID-19-positive patients admitted to the Intensive care unit (ICU) of a tertiary care hospital from June to September 2020. Blood culture, identification and antibiotic sensitivity testing (AST) were done using automated systems. Values of D-dimer, CRP, PCT and TC were obtained using immunoturbidimetric assay, chemiluminescent immunoassay, immunochromatographic testing and automated haematology analyser respectively.   Results: Among 143 blood culture samples obtained from 122 COVID-19 positive patients, 80 flagged positive. Out of the 80 isolates obtained, 53 (66.25%), 17 (21.25%) and 10 (12.5%) were gram-positive bacteria, gram-negative bacteria and candida respectively.  The blood culture positivity rate was 25.4%. Acinetobacter spp. and K. pneumoniae showed high levels of antibiotic resistance. Among 16 patients with elevated PCT, 15 (93.7%) patients showed positive blood cultures. CRP of >5 mg/L and deranged total WBC counts were seen among all blood culture-positive patients. In 100 patients with elevated D-dimer, 54% (54/100) patients showed positive blood culture.   Conclusion: From this study, we conclude that early identification of pathogens and initiation of appropriate antimicrobial therapy is crucial for managing sepsis associated with COVID-19 infection. PCT, CRP, TC and D-dimer can help as biomarkers in the management of COVID-19 patients with secondary bloodstream infections (BSI).