Yu David, Larsson Anna, Parke Åsa, Unge Christian, Henning Claes, Sundén-Cullberg Jonas, Somell Anna, Strålin Kristoffer, Özenci Volkan
Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden.
Functional Area of Emergency Medicine, Karolinska University Hospital, Stockholm, Sweden.
Front Microbiol. 2020 Jul 23;11:1639. doi: 10.3389/fmicb.2020.01639. eCollection 2020.
Optimal sampling is critical for the performance of blood cultures (BCs). Most guidelines recommend collecting 40 ml of blood, divided between two venipuncture sites, i.e., multi-sampling strategy (MSS). Sampling through a single venipuncture site, i.e., single-sampling strategy (SSS) is easier; however, the diagnostic performance of SSS compared to MSS remains unknown. Thus, we aimed to study if SSS is non-inferior to MSS for detection of pathogenic microorganisms.
A prospective, paired, non-inferiority design was used. Patients with clinically suspected sepsis admitted to an Emergency Department were included. Six BC bottles were simultaneously collected, consisting of four BC bottles from the first arm and two from the other arm. SSS consisted of BC bottles 1, 2, 3, and 4, and MSS consisted of BC bottles 1, 2, 5, and 6. Samples were incubated in a BacT/ALERT BC system.
The final analysis included 549 episodes. Pathogenic microorganisms were detected in 162 cases (29.5%) with MSS and 160 cases (29.1%) with SSS, yielding an absolute difference of 0.36%, with a 95% confidence interval of -1.33 to 2.06%, which did not exceed the predefined non-inferiority margin of 5%. MSS tended to produce more contaminant growth (7.3% of cases) than SSS (5.3% of cases; = 0.072).
The study showed that SSS was non-inferior to MSS in detecting pathogenic microorganisms and supports the use of SSS as a routine method.
最佳采样对于血培养（BC）的性能至关重要。大多数指南建议采集40毫升血液，分两个静脉穿刺部位采集，即多采样策略（MSS）。通过单个静脉穿刺部位采样，即单采样策略（SSS）更简便；然而，与MSS相比，SSS的诊断性能尚不清楚。因此，我们旨在研究SSS在检测致病微生物方面是否不劣于MSS。
采用前瞻性、配对、非劣效性设计。纳入急诊科临床怀疑患有败血症的患者。同时采集6个血培养瓶，其中4个血培养瓶采自一侧手臂，另外2个采自另一侧手臂。SSS包括血培养瓶1、2、3和4，MSS包括血培养瓶1、2、5和6。样本在BacT/ALERT血培养系统中培养。
最终分析纳入549例次。MSS检测出致病微生物162例（29.5%），SSS检测出160例（29.1%），绝对差异为0.36%，95%置信区间为-1.33%至2.06%，未超过预先设定的5%的非劣效性界值。MSS产生污染性生长的比例（7.3%）高于SSS（5.3%；P = 0.072）。
该研究表明，SSS在检测致病微生物方面不劣于MSS，并支持将SSS作为常规方法使用。
