Objectives

The role of follow-up blood cultures (FUBCs) in the management of Gram-negative bacteraemia (GNB) is poorly understood. We aimed to determine the utility of FUBCs in identifying patients with increased mortality risk.

Methods

An observational study with a prospectively enrolled cohort of adult inpatients with GNB was conducted at Duke University Health System from 2002 to 2015. FUBCs were defined as blood cultures performed from 24 hours to 7 days from initial positive blood culture.

Results

Among 1702 patients with GNB, 1164 (68%) had FUBCs performed. When performed, FUBCs were positive in 20% (228/1113) of cases. FUBC acquisition was associated with lower all-cause in-hospital mortality (108/538, 20%, vs. 176/1164, 15%; p 0.01) and attributable in-hospital mortality (78/538, 15%, vs. 98/1164, 8%; p < 0.0001). Propensity score–weighted Cox proportional hazards models revealed that obtaining FUBCs was associated with reductions in all-cause (hazard ratio (HR) 0.629; 95% confidence interval (CI), 0.511–0.772; p < 0.0001) and attributable mortality (HR 0.628; 95% CI, 0.480–0.820; p 0.0007). Positive FUBCs were associated with increased all-cause mortality (49/228, 21%, vs. 110/885, 11%; p 0.0005) and attributable mortality (27/228, 12%, vs. 61/885, 7%; p 0.01) relative to negative FUBCs. Propensity score–weighted Cox proportional hazards models revealed that positive FUBCs were associated with increased all-cause (HR 2.099; 95% CI, 1.567–2.811; p < 0.0001) and attributable mortality (HR 1.800; 95% CI, 1.245–2.603; p 0.002). In a calibration analysis, a scoring system accurately identified patients at high risk of positive FUBCs.

Conclusions

Rates of positive FUBCs were high and identified patients at increased risk for mortality. Clinical variables can identify patients at high risk for positive FUBCs. FUBCs should be considered in the management of GNB.

中文翻译：

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积极的随访血液培养确定了革兰氏阴性菌血症患者的高死亡风险。

目标

后续血液培养（FUBCs）在革兰氏阴性菌血症（GNB）的管理中的作用知之甚少。我们旨在确定FUBC在确定死亡风险增加的患者中的实用性。

方法

杜克大学医疗系统于2002年至2015年对前瞻性登记的GNB成人住院患者进行了一项观察性研究。FUBC定义为从最初的阳性血液培养开始24小时至7天进行的血液培养。

结果

在1702名GNB患者中，有1164名（68％）进行了FUBC。进行检查时，FUBC在20％（228/1113）的病例中为阳性。FUBC的获得与院内全因死亡率较低（108/538，20％，176/164，15％; p 0.01）和可归因的院内死亡率（78/538，15％，vs 98）相关/ 1164，8％； p <0.0001）。倾向得分加权的Cox比例风险模型显示，获得FUBC与降低全因（风险比（HR）0.629； 95％置信区间（CI），0.511-0.772； p <0.0001）和可归因的死亡率（HR 0.628）相关。 ; 95％CI，0.480–0.820; p 0.0007）。FUBC阳性与全因死亡率增加（49/228，21％，vs. 110/885，11％; p 0.0005）和归因死亡率（27/228，12％，vs. 61/885，7％; p 0.01）相对于阴性FUBC。倾向得分加权的Cox比例风险模型显示，阳性FUBC与全因增加（HR 2.099; 95％CI，1.567–2.811; p <0.0001）和归因死亡率（HR 1.800; 95％CI，1.245–2.603; P <0.0001）相关。 p 0.002）。在校准分析中，评分系统可准确识别出高阳性FUBC风险患者。

结论

FUBCs阳性率很高，并且确定了死亡风险增加的患者。临床变量可以确定高阳性FUBCs风险的患者。在GNB的管理中应考虑FUBC。