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Defining persistent Staphylococcus aureus bacteraemia: secondary analysis of a prospective cohort study

Richard Kuehl, Laura Morata, Christian Boeing, et al

Lancet Infect Dis Published:August 04, 2020 DOI:https://doi.org/10.1016/S1473-3099(20)30447-3

Summary 摘要

Background 背景

Staphylococcus aureus persistent bacteraemia is only vaguely defined and the effect of different durations of bacteraemia on mortality is not well established. Our primary aim was to analyse mortality according to duration of bacteraemia and to derive a clinically relevant definition for persistent bacteraemia.

持续性金葡菌菌血症定义并不明确，菌血症不同持续时间对病死率的影响也未确定。我们主要的研究目的是根据菌血症持续时间分析病死率，从而确定持续性菌血症的临床定义。

Methods 方法

We did a secondary analysis of a prospective observational cohort study at 17 European centres (nine in the UK, six in Spain, and two in Germany), with recruitment between Jan 1, 2013, and April 30, 2015. Adult patients who were consecutively hospitalised with monomicrobial S aureus bacteraemia were included. Patients were excluded if no follow-up blood culture was taken, if the first follow-up blood-culture was after 7 days, or if active antibiotic therapy was started more than 3 days after first blood culture. The primary outcome was 90-day mortality. Univariable and time-dependent multivariable Cox regression analysis were used to assess predictors of mortality. Duration of bacteraemia was defined as bacteraemic days under active antibiotic therapy counting the first day as day 1.

我们对一项前瞻观察性队列研究进行了二次分析。这项研究在2013年1月1日至2015年4月30日间进行，纳入了欧洲17个中心（英国9个，西班牙6个，德国2个）连续收治的单纯金葡菌菌血症的成年住院患者。排除标准包括没有留取后续血培养，或后续首次血培养在7天后留取，或首次血培养后超过3天没有使用有效抗生素。主要预后指标为90天病死率。采用单因素及时间依赖性多因素Cox回归分析评价病死率预测指标。菌血症持续时间定义为在有效抗生素治疗下菌血症持续天数。

Findings 结果

Of 1588 individuals assessed for eligibility, 987 were included (median age 65 years [IQR 51–75]; 625 [63%] male). Death within 90 days occurred in 273 (28%) patients. Patients with more than 1 day of bacteraemia (315 [32%]) had higher Charlson comorbidity index and sequential organ failure assessment scores and a longer interval from first symptom to first blood culture. Crude 90-day mortality increased from 22% (148 of 672) with 1 day of bacteraemia, to 39% (85 of 218) with 2–4 days, 43% (30 of 69) with 5–7 days, and 36% (10 of 28) with more than 7 days of bacteraemia. Metastatic infections developed in 39 (6%) of 672 patients with 1 day of bacteraemia versus 40 (13%) of 315 patients if bacteraemia lasted for at least 2 days. The second day of bacteraemia had the highest HR and earliest cutoff significantly associated with mortality (adjusted hazard ratio 1·93, 95% CI 1·51–2·46; p<0·0001).

共筛查了1588名患者，最终纳入987名患者（中位年龄 65 岁 [IQR 51–75]; 625名 [63%] 男性）。90天内 273名 (28%) 患者死亡。菌血症持续超过1天的患者 (315 [32%]) Charlson合并症指数及SOFA评分较高，从首发症状到首次血培养时间间隔较长。90天粗病死率从菌血症持续1天者的 22% (148/672) 增加到持续2-4天的 39% (85/218)，5–7天的 43% (30/69)，以及超过7天的 36% (10/28)。菌血症持续1天的672名患者中39名 (6%)，以及菌血症持续至少2天的315名患者中 40名 (13%) 发生感染转移。第2天菌血症与病死率相关性HR最高，且临界值最早(校正风险比 1·93, 95% CI 1·51–2·46; p<0·0001)。

Interpretation 结论

We suggest redefining the cutoff duration for persistent bacteraemia as 2 days or more despite active antibiotic therapy. Our results favour follow-up blood cultures after 24 h for early identification of all patients with increased risk of death and metastatic infection.

我们建议将持续性菌血症的时间临界值重新定义为有效抗生素治疗下菌血症持续2天或更久。我们的结果支持在24小时后留取后续血培养，以早期鉴别死亡及感染转移风险增加的所有患者。

Funding

None.