Unique blood culture for diagnosis of bloodstream infections in emergency departments: a prospective multicentre study

Abstract

Detection of microorganisms by blood cultures (BCs) is essential in managing patients with bacteraemia. Rather than the number of punctures, the volume of blood drawn is considered paramount in efficient and reliable detection of microorganisms. We performed a 1-year prospective multicentre study in adult emergency departments of three French university hospitals comparing two methods for BCs: a unique blood culture (UBC) collecting a large volume of blood (40 mL) and the standard method of multiple blood cultures (MBC). The performances of both methods for bacterial contamination and efficient microbial detection were compared, each patient serving as his own control. Amongst the 2314 patients included, three hundred were positive for pathogens (n=245) or contaminants (n=55). Out of the 245 patients, 11 were positive for pathogens by UBC but negative by MBC and seven negative by UBC but positive by MBC (p 0.480). In the subgroup of 137 patients with only two BCs, UBC was superior to MBC (p 0.044). Seven and 17 patients had contaminated BCs by UBC and MBC only, respectively (p 0.062). Considering the sums of pathogens missed and contaminants, UBC significantly outperformed MBC (p 0.045). Considering the complete picture of cost savings, efficient detection of microorganisms and decrease in contaminations, UBC offers an interesting alternative to MBC.

Utility of anaerobic bottles for the diagnosis of bloodstream infections

“…We analyzed herein the efficiency of anaerobic BC in our hospital, in which care of immunosuppressed patients is prominent; we also tried to determine which patients would really benefit from anaerobic BC. In our study, 11.9% of BC (aerobic and/or anaerobic bottle positive) were positive, which is in the range of previously published studies (6.8 to 11.6%) [15][16][17][18][19]. The number of positive BC using anaerobic bottles (7.7%) was also consistent with previous studies (8.9 to 13%) [14][15][16][17][18] .…”

“…Contaminations are reported in up to 50% of BC in the literature, CoNS being the most frequently isolated microorganisms, as shown in our study. The high amount of contamination by skin flora in our study may be explained, in part, by a majority of patients having central line, increasing the risk for contamination when blood samples are taken via the catheter [19]. This high rate of contaminants and also the growth of aerobic bacteria in anaerobic bottles may be also interpreted as an evidence for poor sampling procedures.…”

“…The improved performance of BC, when anaerobic bottles are used, may be related to the increase volume of collected blood volume and also to the richer medium that may better support bacterial growth. By increasing the volume of collected blood the detection of facultative anaerobic pathogens has been shown to be improved [19]. However, volume of collected blood per bottle could not be evaluated in our study.…”

Relevance of blood cultures in acute pyelonephritis in a single-center retrospective study

“…If 11 BC were useful for a total of 264 sampled tests (i.e., one every 24 patients), which represents an approximate cost of a valuable BC to be 840€ or 1150 USD. To further diminish the expenses of BC, Dargère et al [13] recently discussed and compared a strategy that collected a large volume of blood (40 mL) in one unique BC to the standard multi-puncture BC strategy in septic ED-patients. The authors argued that with a larger volume of blood drawn in a unique bottle, they outperformed the standard procedure in bacteriological terms with significantly decreased charges.…”

Training of French Nursing Students on Drawing Blood Culture: Results from a Broad Electronic Survey

“…Thus, opportunities exist to improve blood culture related practices for nursing students to reduce blood culture contamination, im-the student despite evidence in favour this last one. Single-sampling reduces the incidence of contamination [31][32][33] and improve the diagnosis performance of blood culture [32,34]. Adequate volume sampling is the most important parameter for the detection of bloodstream infection, thus a minimal of 8-10 mL of blood is required [26].…”