Neves Lariessa, Marra Alexandre Rodrigues, Camargo Thiago Zinsly Sampaio, dos Santos Maura Cristina, Zulin Flávia, da Silva Patrícia Candido, de Moura Natália Ariede, Victor Elivane da Silva, Pasternak Jacyr, dos Santos Oscar Fernando Pavão, Edmond Michael B, Martino Marines Dalla Valle
Intensive Care Unit, Hospital Israelita Albert Einstein, São Paulo, Brazil.
Instituto Israelita de Ensino e Pesquisa Albert Einstein, São Paulo, Brazil.
BMC Res Notes. 2015 Aug 28;8:383. doi: 10.1186/s13104-015-1365-8.
The collection of blood cultures is an extremely important method in the management of patients with suspected infection. Microbiology laboratories should monitor blood culture collection.
Over an 8-month period we developed a prospective, observational study in an adult Intensive Care Unit (ICU). We correlated the mass contained in the blood vials with blood culture positivity and we also verified the relationship between the mass of blood and blood volume collected for the diagnosis of bloodstream infection (BSI), as well as we explored factors predicting positive blood cultures.
We evaluated 345 patients with sepsis, severe sepsis or septic shock for whom blood culture bottles were collected for the diagnosis of BSI. Of the 55 patients with BSI, 40.0% had peripheral blood culture collection only. BSIs were classified as nosocomial in 34.5%. In the multivariate model, the blood culture mass (in grams) remained a significant predictor of positivity, with an odds ratio 1.01 (i.e., for each additional 1 mL of blood collected there was a 1% increase in positivity; 95% CI 1.01-1.02, p = 0.001; Nagelkerke R Square [R(2)] = 0.192). For blood volume collected, the adjusted odds ratio was estimated at 1.02 (95% CI: 1.01-1.03, p < 0.001; R(2) = 0.199). For each set of collected blood cultures beyond one set, the adjusted odds ratio was estimated to be 1.27 (95% CI: 1.14-1.41, p < 0.001; R(2) = 0.221).
Our study was a quality improvement project that showed that microbiology laboratories can use the weight of blood culture bottles to determine if appropriate volume has been collected to improve the diagnosis of BSI.
血培养采集是疑似感染患者管理中的一项极其重要的方法。微生物实验室应监测血培养采集情况。
在8个月的时间里，我们在一个成人重症监护病房（ICU）开展了一项前瞻性观察性研究。我们将血瓶中所含血量与血培养阳性情况进行关联，还验证了用于诊断血流感染（BSI）所采集的血量与血容量之间的关系，并探索了预测血培养阳性的因素。
我们评估了345例患有脓毒症、严重脓毒症或脓毒性休克且采集血培养瓶用于诊断BSI的患者。在55例BSI患者中，40.0%仅进行了外周血培养采集。34.5%的BSI被分类为医院感染。在多变量模型中，血培养血量（以克为单位）仍然是阳性的显著预测因素，优势比为1.01（即，每多采集1 mL血液，阳性率增加1%；95%置信区间1.01 - 1.02，p = 0.001；Nagelkerke R方[R(2)] = 0.192）。对于采集的血容量，调整后的优势比估计为1.02（95%置信区间：1.01 - 1.03，p < 0.001；R(2) = 0.199）。对于超过一组的每组采集血培养，调整后的优势比估计为1.27（95%置信区间：1.14 - 1.41，p < 0.001；R(2) = 0.221）。
我们的研究是一个质量改进项目，表明微生物实验室可以利用血培养瓶的重量来确定是否采集了合适的血量，以改善BSI的诊断。
