Detailed Analysis of the Characteristics of Sample Volume in Blood Culture Bottles

Abstract

Blood volume is the most important variable for the detection of microorganisms in blood cultures (BCs). Most standards recommend 40 to 60 ml blood, collected in several BC bottles filled up to 10 ml. We measured blood volume in individual BC bottles and analyzed the associations of hospital, bottle type, day of the week, daily sampling time, and age and sex of the patient with sampling volume and BC result. The variation in blood volume per BC bottle was analyzed in a mixed linear model using hospital, bottle type, weekday, sampling time, age, and sex as fixed factors and patient identification (ID) and episode as random factors to control for repetitive sampling of individual patients. Only 18% of all bottles were filled with the recommended 8 to 10 ml, and 47% were filled with less than 8 ml. The mean (± standard error) volume was larger in positive bottles (9.09 ± 0.15) than in negative bottles (8.47 ± 0.07) (P < 0.001). Blood volume was larger in BacT/Alert-FA Plus bottles than in -FN Plus BC bottles (P < 0.001). There were significantly lower volumes collected during the night (P < 0.001). The volume of blood collected decreased significantly with increasing patient age (P < 0.001). Larger volumes were collected from male patients than from female patients: 8.78 (± 0.06) versus 8.36 (± 0.06) ml (mean ± standard error [SE]), respectively (P < 0.001). The odds of detecting a positive patient increases by 13% for each additional milliliter of blood drawn. Our results show that we need to work actively with the development of blood sampling routines to overcome age and sex effects and to optimize blood sampling volumes.

Detection of bacterial co-infections and prediction of fatal outcomes in COVID-19 patients presenting to the emergency department using a 29 mRNA host response classifier

“…Existing diagnostic tests have major limitations. Gold standard bacterial cultures often take days to result, are limited by the ability of the organism to grow in the culture medium, and require a large sample volume when testing complex patient samples like blood 14,15 .…”

Digital microbiology

“…Pre-analytics addresses the collection and quality of samples transported to the laboratory. For example, the filling volume of blood culture flasks, which directly correlates with positivity rates and the analytical sensitivity of blood culture diagnostics [18]. Modern blood culture systems provide automated weighting of blood cultures to determine the collected volumes and provide a feedback to the laboratory information system (LIS) [19].…”

Mass Spectrometry Proteotyping-Based Detection and Identification of Staphylococcus aureus, Escherichia coli, and Candida albicans in Blood

“…However, false negative blood cultures may result from the presence of antibiotics in the culture, originating from the patient blood, from infections caused by opportunistic microorganisms that grow poorly in standardized, automated, blood culture systems or that only few viable cells of the pathogen have been recovered from patient blood samples ( Sinha et al., 2018 ). Furthermore, the success of recovery of microorganisms in cases of bacteremia has been shown to be linked to the volume of blood initially taken ( Murray and Masur, 2012 ; Skvarc et al., 2013 ; Loonen et al., 2014 ; Opota et al., 2015 ; Henning et al., 2019 ). In some cases, however, it is not possible to recover large volumes of blood ( Kirn and Weinstein, 2013 ), for example, from newborn infants at neonatal intensive care units, wherein culture-independent diagnostics methods, i.e., not relying on blood cultures, and thus not needing large volumes of patient blood, would be of utmost importance ( Steinbach, 2016 ; Henning et al., 2019 ).…”

“…Furthermore, the success of recovery of microorganisms in cases of bacteremia has been shown to be linked to the volume of blood initially taken ( Murray and Masur, 2012 ; Skvarc et al., 2013 ; Loonen et al., 2014 ; Opota et al., 2015 ; Henning et al., 2019 ). In some cases, however, it is not possible to recover large volumes of blood ( Kirn and Weinstein, 2013 ), for example, from newborn infants at neonatal intensive care units, wherein culture-independent diagnostics methods, i.e., not relying on blood cultures, and thus not needing large volumes of patient blood, would be of utmost importance ( Steinbach, 2016 ; Henning et al., 2019 ).…”