Department of Anesthesiology, University Hospital Greifswald, Germany.
Department of Anesthesiology, University Hospital Greifswald, Germany.
Clin Microbiol Infect. 2019 Mar;25(3):326-331. doi: 10.1016/j.cmi.2018.05.016. Epub 2018 Jun 4.
Sepsis guidelines recommend obtaining blood cultures before starting anti-infective therapy in patients with sepsis. However, little is known of how antibiotic treatment before sampling affects bacterial growth. The aim of this study was to compare the results of blood cultures drawn before and during antibiotic therapy.
Prospective clinical cohort study of septic patients. Adult intensive care unit patients with two or three blood culture sets at the beginning of sepsis between 2010 and 2017 were included. Patients with blood culture samples obtained before antibiotic therapy were compared with patients with samples taken during antibiotic therapy. Blood culture positivity, defined as presence of a microbiological pathogen, was compared between the groups. Logistic regression was performed to adjust the impact of different factors with respect to blood culture positivity.
In total, 559 patients with 1364 blood culture sets at the beginning of sepsis were analysed. Blood culture positivity was 50.6% (78/154) among patients with sepsis who did not receive antibiotics and only 27.7% (112/405) in those who were already receiving antibiotics (p <0.001). Logistic regression revealed antibiotic therapy as an independent factor for less pathogen identification (odds ratio 0.4; 95% CI 0.3-0.6). Gram-positive pathogens (28.3% (111/392) versus 11.9% (116/972); p <0.001) and also Gram-negative pathogens (16.3% (64/392) versus 9.3% (90/972); p <0.001) were more frequent in blood culture sets drawn before antibiotic therapy compared with sets obtained during antibiotic therapy.
Obtaining blood cultures during antibiotic therapy is associated with a significant loss of pathogen detection. This strongly emphasizes the current recommendation to obtain blood cultures before antibiotic administration in patients with sepsis.
脓毒症指南建议在脓毒症患者开始抗感染治疗前采集血培养。然而，关于采样前抗生素治疗如何影响细菌生长知之甚少。本研究旨在比较抗生素治疗前后采集的血培养结果。
这是一项 2010 年至 2017 年间脓毒症患者的前瞻性临床队列研究。纳入了在脓毒症开始时接受了两次或三次血培养的成年重症监护病房患者。将未接受抗生素治疗的患者的血培养样本与接受抗生素治疗时采集的样本进行比较。比较两组血培养阳性率（定义为存在微生物病原体）。采用逻辑回归分析不同因素对血培养阳性率的影响。
共分析了 559 例患者的 1364 份血培养起始时的样本。未接受抗生素治疗的脓毒症患者血培养阳性率为 50.6%（78/154），而已经接受抗生素治疗的患者血培养阳性率仅为 27.7%（112/405）（p<0.001）。逻辑回归显示抗生素治疗是病原体检出率降低的独立因素（比值比 0.4；95%可信区间 0.3-0.6）。与抗生素治疗时采集的血培养相比，抗生素治疗前采集的血培养中革兰阳性病原体（28.3%（111/392）比 11.9%（116/972）；p<0.001）和革兰阴性病原体（16.3%（64/392）比 9.3%（90/972）；p<0.001）更为常见。
在抗生素治疗期间采集血培养会显著降低病原体的检出率。这强烈强调了目前在脓毒症患者中推荐在给予抗生素前采集血培养的建议。
