Objectives

Bloodstream infection has a high mortality rate. It is not clear whether laboratory-based rapid identification of the organisms involved would improve outcome.

Methods

The RAPIDO trial was an open parallel-group multicentre randomized controlled trial. We tested all positive blood cultures from hospitalized adults by conventional methods of microbial identification and those from patients randomized (1:1) to rapid diagnosis in addition to matrix-assisted desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) performed directly on positive blood cultures. The only primary outcome was 28-day mortality. Clinical advice on patient management was provided to members of both groups by infection specialists.

Results

First positive blood culture samples from 8628 patients were randomized, 4312 into rapid diagnosis and 4136 into conventional diagnosis. After prespecified postrandomization exclusions, 2740 in the rapid diagnosis arm and 2810 in the conventional arm were included in the mortality analysis. There was no significant difference in 28-day survival (81.5% 2233/2740 rapid vs. 82.3% 2313/2810 conventional; hazard ratio 1.05, 95% confidence interval 0.93–1.19, p 0.42). Microbial identification was quicker in the rapid diagnosis group (median (interquartile range) 38.5 (26.7–50.3) hours after blood sampling vs. 50.3 (47.1–72.9) hours after blood sampling, p < 0.01), but times to effective antimicrobial therapy were no shorter (respectively median (interquartile range) 24 (2–78) hours vs. 13 (2–69) hours). There were no significant differences in 7-day mortality or total antibiotic consumption; times to resolution of fever, discharge from hospital or de-escalation of broad-spectrum therapy or 28-day Clostridioides difficile incidence.

Conclusions

Rapid identification of bloodstream pathogens by MALDI-TOF MS in this trial did not reduce patient mortality despite delivering laboratory data to clinicians sooner.

中文翻译：

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快速微生物鉴定对血液感染临床预后的影响：RAPIDO随机试验。

目标

血液感染具有很高的死亡率。尚不清楚基于实验室的有关生物的快速鉴定是否会改善结果。

方法

RAPIDO试验是开放式平行组多中心随机对照试验。除了常规的基质辅助解吸电离-飞行时间质谱（MALDI-TOF MS）外，我们还通过常规的微生物鉴定方法对住院成人的所有阳性血液培养物进行了测试，对随机（1：1）进行快速诊断的患者进行了阳性培养。在积极的血液文化。唯一的主要结局是28天的死亡率。感染专家向两组患者提供了有关患者管理的临床建议。

结果

将来自8628例患者的首批阳性血液培养样本随机分组，其中4312例进行快速诊断，4136例进行常规诊断。在预先指定的随机后排除后，死亡率分析包括快速诊断组中的2740和常规组中的2810。28天生存率无显着差异（常规的81.5％2233/2740快速与传统的82.3％2313/2810；危险比1.05，95％置信区间0.93-1.19，p 0.42）。在快速诊断组中，微生物鉴定更快（中位数（四分位数间距）在采血后38.5（26.7-50.3）小时，而在采血后50.3（47.1-72.9）小时，p <0.01），但是有效的抗菌治疗时间不更短（分别为中位（四分位间距）24（2–78）小时与13（2–69）小时）。7天死亡率或抗生素总消耗量无显着差异；解决发烧，出院或广谱治疗升级或28天的时间艰难梭菌的发生率。

结论

尽管通过MALDI-TOF MS快速鉴定出血液中的病原体，尽管能尽快将实验室数据提供给临床医生，但并未降低患者的死亡率。