Evaluation of the blood volume effect on the diagnosis of bacteremia in automated blood culture systems

Background: Blood culture volume is the most important variable in detecting bacteremia and fungemia. However, the majority of hospitals in Taiwan do not meet the criteria for an ideal blood culture volume (8-10 mL per bottle, two bottles per set) during collection. Methods: The object of this study is to initiate an educational program for healthcare workers to increase blood volume collection and to evaluate the relationship between blood volumes and bacteremia recovery rate for detecting bacteremia and fungemia effectively by using the BD BACTEC 9240 blood culture system. Results: After education, the blood sample volume >= 5 mL group increased from 2.93% to 71.24%. For a total of 4,844 bottles, the relative improvement in recovery rate for detection has increased by 17.81% between the <5 mL group and the >= 5 mL group. The recovery rates for the low-volume (<3 mL), mid-volume (3-7 mL), high-volume (8-10 mL) and extreme high-volume (>10 mL) groups are 13.31%, 15.02%, 17.68%, and 14.96%, respectively. Conclusion: With good blood collection practice, our study found that blood volume obtained was in direct proportion to recovery rate for the detection of bacteremia and fungemia. Copyright (c) 2012, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC. All rights reserved.