Division of Infectious Diseases and Hospital Epidemiology, University Hospital Basel, Basel, Switzerland.
Clin Microbiol Infect. 2012 Sep;18(9):E355-61. doi: 10.1111/j.1469-0691.2012.03964.x. Epub 2012 Jul 12.
Coagulase-negative staphylococci (CoNS) are frequent contaminants of blood cultures. We aimed to evaluate the systemic inflammatory response syndrome (SIRS) criteria in patients with CoNS bacteraemia for discrimination between true bloodstream infection (BSI) and contamination. Prospective evaluation was carried out of clinical and laboratory parameters in adults with at least one positive blood culture with CoNS at the University Hospital of Basel between 2003 and 2007. Of 3060 positive blood cultures, 654 episodes of CoNS bacteraemia were identified. Of these, 232 (35%) were considered to be true BSI and 422 (65%) were considered to be contamination. Overall, 80% of study participants had at least one SIRS criterion, fever being the most common, and 49% had at least two SIRS criteria. In the multivariate analysis, independent predictors of BSI were fever or hypothermia (OR 2.93, 95% CI 1.91-4.5), tachycardia (OR 2.29, 95% CI 1.50-3.50), tachypnoea (OR 2.4, 95% CI 1.30-4.43), leucocytosis or leucopenia (OR 4.15, 95% CI 2.17-6.36) and the presence of a central venous line (OR 5.38, 95% CI 3.25-8.88). The probability of BSI increased with each additional SIRS criterion, ranging from 42.4% in patients with only one SIRS criterion to 56.7% for those with two criteria, and 72.3% for patients with three SIRS criteria. A positive blood culture with CoNS most likely represents true BSI if the patient has at least three SIRS criteria or two SIRS criteria and a central venous catheter. These simple bedside criteria may guide decision to treat, decreasing the use of glycopeptides.
凝固酶阴性葡萄球菌（CoNS）是血培养常见的污染菌。我们旨在评估凝固酶阴性葡萄球菌菌血症患者的全身炎症反应综合征（SIRS）标准，以区分真正的血流感染（BSI）和污染。对 2003 年至 2007 年期间在巴塞尔大学医院至少有一次 CoNS 阳性血培养的成人进行了临床和实验室参数的前瞻性评估。在 3060 次阳性血培养中，确定了 654 次凝固酶阴性葡萄球菌菌血症发作。其中，232 例（35%）被认为是真正的 BSI，422 例（65%）被认为是污染。总的来说，80%的研究参与者至少有一个 SIRS 标准，发热最常见，49%的患者至少有两个 SIRS 标准。在多变量分析中，BSI 的独立预测因素是发热或低体温（OR 2.93，95%CI 1.91-4.5）、心动过速（OR 2.29，95%CI 1.50-3.50）、呼吸急促（OR 2.4，95%CI 1.30-4.43）、白细胞增多或白细胞减少（OR 4.15，95%CI 2.17-6.36）和中央静脉导管的存在（OR 5.38，95%CI 3.25-8.88）。随着每个额外的 SIRS 标准的增加，BSI 的概率增加，从只有一个 SIRS 标准的患者的 42.4%到有两个 SIRS 标准的患者的 56.7%，到有三个 SIRS 标准的患者的 72.3%。如果患者有至少三个 SIRS 标准或两个 SIRS 标准和中央静脉导管，CoNS 阳性血培养极有可能代表真正的 BSI。这些简单的床边标准可以指导治疗决策，减少糖肽的使用。
