CC:血培养阳性时间作为铜绿假单胞菌血流感染成人患者导管相关菌血症和死亡率的预测指标

Abstract

Background: Time to positivity (TTP) and differential TTP (DTP) emerge as diagnostic and prognostic tools for bloodstream infections (BSI) though specific cut-off values need to be determined for each pathogen. Pseudomonas aeruginosa BSI (PAE-BSI) is of critical concern, particularly in immunocompromised patients, due to high mortality rates. Catheter-related infections are a common cause, necessitating rapid and accurate diagnostic tools for effective management (source-control).

背景：血培养阳性时间（TTP）和差异阳性时间（DTP）已成为血流感染（BSI）的诊断和预后工具，但需要针对每种病原体确定具体的临界值。铜绿假单胞菌血流感染（PAE-BSI）因其高死亡率而备受关注，尤其是在免疫功能低下患者中。导管相关感染是其常见原因，因此需要快速、准确的诊断工具以实现有效管理（感染源控制）。

Methods: Unicentric retrospective observational study analyzing the diagnostic utility and best cut-off values of time to positivity (TTP) and differential time to positivity (DTP) to identify catheter-related PAE-BSI and the association of TTP with 30-day mortality.

方法：本研究为单中心回顾性观察研究，旨在分析TTP和DTP的诊断效用及最佳临界值，以识别导管相关PAE-BSI，并探讨TTP与30天死亡率的关系。

Results: 1177 PAE-BSI cases TTP were included in the study. TTP was available in all episodes whereas DTP was available in 355 episodes. Breakthrough bacteremia disregarding the TTP, more than one positive blood culture or > 7 days with a catheter in place and both a TTP < 13h and a DTP > 2h were independently associated to catheter-related PAE-BSI. Secondly, lower TTP were significantly associated with higher 30-day mortality rates in both catheter-related and non-catheter-related PAE-BSI. For catheter-related infections, TTP < 14h exacerbated mortality among patients among patients in whom the catheter was not removed within 48h (OR 2.9[1.04-8]); whereas for other sources TTP < 16h increased mortality (OR 1.6[1.1-2.4]) particularly when the empiric antibiotic therapy was not active (OR 3.8[1.5-10]).

结果：研究共纳入1177例PAE-BSI患者的TTP数据。所有病例均记录了TTP，而355例记录了DTP。研究发现，无论TTP如何，突破性菌血症、多次血培养阳性或导管留置时间超过7天，以及TTP < 13小时且DTP > 2小时，均与导管相关PAE-BSI独立相关。其次，较短的TTP与导管相关和非导管相关PAE-BSI的30天死亡率显著相关。对于导管相关感染，若导管未在48小时内拔除，TTP < 14小时会显著增加死亡率（OR 2.9[1.04-8]）；而对于其他感染源，TTP < 16小时会增加死亡率（OR 1.6[1.1-2.4]），尤其是在经验性抗生素治疗无效时（OR 3.8[1.5-10]）。

Conclusion: These findings advocate for the routine use of TTP over DTP as a diagnostic tool to guide timely interventions such as catheter removal, thereby potentially improving patient outcomes in PAE-BSI. Moreover, lower TTP have also prognostic implications in both catheter-related and non-catheter-related infections.

结论：本研究支持将TTP而非DTP作为常规诊断工具，以指导及时干预（如导管拔除），从而可能改善PAE-BSI患者的预后。此外，较短的TTP在导管相关和非导管相关感染中均具有预后意义。