Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutegrid.4714.6t, Stockholm, Sweden.
Functional Area of Emergency Medicine, Karolinska University Hospital, Stockholm, Sweden.
J Clin Microbiol. 2022 Feb 16;60(2):e0193521. doi: 10.1128/JCM.01935-21. Epub 2021 Dec 1.
The performance of blood cultures (BCs) relies on optimal sampling. Sepsis guidelines do not specify which sampling protocol to use but recommend two sets of BC bottles, each set containing one aerobic and one anaerobic bottle. For the single-site sampling (SSS) protocol, only one venipuncture is performed for all four bottles. The predominating multisite sampling (MSS) protocol implies that BC bottles are collected from two separate venipuncture sites. The aim of this study was to compare SSS and MSS. Primary outcomes were number of BC sets collected, sample volume, and diagnostic performance. This was a retrospective clinical study comparing BC results in an emergency department before and after changing the sampling protocol to SSS from MSS. All BC samples were incubated in the BacT/Alert BC system. The analysis included 5,248 patients before and 5,364 patients after the implementation of SSS. There was a significantly higher proportion of positive BCs sampled with SSS compared with MSS, 1,049/5,364 (19.56%) and 932/5,248 (17.76%), respectively (0.018). This difference was due to a higher proportion of solitary BC sets (two BC bottles) in MSS. Analyzing only patients with the recommended four BC bottles, there was no difference in positivity. SSS had a higher proportion of BC bottles with the recommended sample volumes of 8-12 ml than MSS (0.001). Changing the sampling protocol to SSS from MSS resulted in higher positivity rates, higher sample volume and fewer solitary BC sets. These advantages of SSS should be considered in future sepsis guidelines.
血培养（BC）的性能依赖于最佳的采样。脓毒症指南并未指定使用哪种采样方案，但建议使用两套 BC 瓶，每套瓶中各包含一个需氧瓶和一个厌氧瓶。对于单点采样（SSS）方案，仅对所有四套瓶进行一次静脉穿刺。主要的多点采样（MSS）方案意味着从两个不同的静脉穿刺部位采集 BC 瓶。本研究旨在比较 SSS 和 MSS。主要结局是采集的 BC 套数、样本量和诊断性能。这是一项回顾性临床研究，比较了改变采样方案为 SSS 前后急诊部的 BC 结果。所有 BC 样本均在 BacT/Alert BC 系统中孵育。分析包括 SSS 实施前的 5248 例患者和 SSS 实施后的 5364 例患者。与 MSS 相比，SSS 采集的阳性 BC 比例明显更高，分别为 1049/5364（19.56%）和 932/5248（17.76%）（0.018）。这种差异是由于 MSS 中单瓶 BC 套（两套 BC 瓶）的比例较高。仅分析推荐的四套 BC 瓶的患者，阳性率没有差异。SSS 中推荐的 8-12ml 样本量的 BC 瓶比例高于 MSS（0.001）。将采样方案从 MSS 改为 SSS 可提高阳性率、增加样本量和减少单瓶 BC 套。在未来的脓毒症指南中应考虑 SSS 的这些优势。
