Department of Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.
Division of Critical Care Medicine, Department of Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.
BMC Infect Dis. 2022 Jul 17;22(1):622. doi: 10.1186/s12879-022-07605-x.
Catheter-related bloodstream infection (CRBSI) is associated with increased morbidity, mortality, and cost of treatment in critically ill patients. A differential time to positivity (DTP) of 120 min or more between blood cultures obtained through the catheter vs. peripheral vein is an indicator of CRBSI with high sensitivity and specificity. However, it is no clear whether pooled sampling would be as efficient as individual sampling in order to reduce costs, contamination, or anemia.
This was a prospective diagnostic study conducted at the medical ICU and semi-ICU of Khon Kaen University's Srinagarind Hospital in Thailand from May 2020 to November 2021. Fifty patients with triple-lumen central venous catheters (CVCs) who were clinically suspected of CRBSI were enrolled. 15 mL of blood was drawn through each catheter lumen, 10 mL of which was inoculated into three blood culture bottles, and the remaining 5 mL was pooled into a single bottle. Sensitivity, specificity, accuracy, and time to positivity of the pooled blood cultures were calculated using individual blood cultures as a reference.
Of the 50 patients enrolled, 14 (28%) were diagnosed with CRBSI, 57.9% of whom were infected with gram-negative bacteria as the causative pathogen (57.9%). Extensively drug-resistant (XDR) Klebsiella pneumoniae was the most common organism. Sensitivity and specificity of the pooled blood sampling method were 69.23% (95% CI [0.44-0.94]) and 97.3% (95% CI [0.92-1.02]), respectively. The area under the ROC curve (AUC) was 0.83 (95% CI [0.68-0.99]). A paired T-Test to compare time to positivity of the pooled blood bottle and the first positive culture from the individual bottles indicated statistical significance (14.9 and 12.4 h, respectively). The mean difference was 2.5 [0.9-4.1] h, with a 95% CI and a p-value of 0.006.
Pooled blood sampling results in a lower sensitivity and longer time to positivity for CRBSI diagnosis in patients with triple-lumen CVCs than individual lumen sampling. Trial registration Retrospectively registered at Thai Clinical Trials Registry. The study was reviewed and approved on 08/03/2022. TCTR identification number is TCTR20220308002.
导管相关血流感染 (CRBSI) 与危重症患者的发病率、死亡率和治疗费用增加有关。导管与外周静脉采集的血培养之间的差异时间至阳性 (DTP) 为 120 分钟或更长时间，是 CRBSI 的一个具有高灵敏度和特异性的指标。然而，尚不清楚与单独采样相比， pooled 采样是否能更有效地降低成本、污染或贫血的风险。
这是一项在泰国孔敬大学诗琳通医院医学 ICU 和半 ICU 进行的前瞻性诊断研究，研究时间为 2020 年 5 月至 2021 年 11 月。共纳入 50 例临床疑似 CRBSI 的三腔中央静脉导管 (CVC) 患者。通过每个导管腔抽取 15 mL 血液，其中 10 mL 接种于三个血培养瓶中，其余 5 mL 混合于一个单独的瓶中。以单独的血培养为参考，计算 pooled 血培养的灵敏度、特异性、准确性和阳性时间。
50 例患者中，14 例（28%）诊断为 CRBSI，其中 57.9%（95%CI [0.44-0.94]）的病原体为革兰氏阴性菌。广泛耐药（XDR）肺炎克雷伯菌是最常见的病原体。pooled 血样采集方法的灵敏度和特异性分别为 69.23%（95%CI [0.44-0.94]）和 97.3%（95%CI [0.92-1.02]）。ROC 曲线下面积（AUC）为 0.83（95%CI [0.68-0.99]）。配对 T 检验比较 pooled 血瓶和第一个阳性培养瓶的阳性时间有统计学意义（分别为 14.9 和 12.4 小时）。平均差异为 2.5 [0.9-4.1] 小时，95%CI 和 p 值分别为 0.006。
与单独的腔采样相比，在三腔 CVC 患者中，pooled 血样采集的灵敏度较低，CRBSI 诊断的阳性时间较长。
泰国临床试验注册中心回顾性注册。该研究于 2022 年 08 月 03 日进行了审查和批准。TCTR 编号为 TCTR20220308002。
