Department of Emergency and Critical Care Medicine, Chiba University Graduate School of Medicine, Inohana Chuo, Chiba, Japan.
Crit Care. 2010;14(2):R27. doi: 10.1186/cc8898. Epub 2010 Mar 4.
Bacteremia is recognized as a critical condition that influences the outcome of sepsis. Although large-scale surveillance studies of bacterial species causing bacteremia have been published, the pathophysiological differences in bacteremias with different causative bacterial species remain unclear. The objective of the present study is to investigate the differences in pathophysiology and the clinical course of bacteremia caused by different bacterial species.
We reviewed the medical records of all consecutive patients admitted to the general intensive care unit (ICU) of a university teaching hospital during the eight-year period since introduction of a rapid assay for interleukin (IL)-6 blood level to routine ICU practice in May 2000. White blood cell count, C-reactive protein (CRP), IL-6 blood level, and clinical course were compared among different pathogenic bacterial species.
The 259 eligible patients, as well as 515 eligible culture-positive blood samples collected from them, were included in this study. CRP, IL-6 blood level, and mortality were significantly higher in the septic shock group (n = 57) than in the sepsis group (n = 127) (P < 0.001). The 515 eligible culture-positive blood samples harbored a total of 593 isolates of microorganisms (Gram-positive, 407; Gram-negative, 176; fungi, 10). The incidence of Gram-negative bacteremia was significantly higher in the septic shock group than in the sepsis group (P < 0.001) and in the severe sepsis group (n = 75, P < 0.01). CRP and IL-6 blood level were significantly higher in Gram-negative bacteremia (n = 176) than in Gram-positive bacteremia (n = 407) (P < 0.001, <0.0005, respectively).
The incidence of Gram-negative bacteremia was significantly higher in bacteremic ICU patients with septic shock than in those with sepsis or severe sepsis. Furthermore, CRP and IL-6 levels were significantly higher in Gram-negative bacteremia than in Gram-positive bacteremia. These findings suggest that differences in host responses and virulence mechanisms of different pathogenic microorganisms should be considered in treatment of bacteremic patients, and that new countermeasures beyond conventional antimicrobial medications are urgently needed.
菌血症被认为是影响脓毒症结局的危急情况。虽然已经发表了关于引起菌血症的细菌种类的大规模监测研究，但不同致病细菌引起的菌血症的病理生理学差异仍不清楚。本研究的目的是探讨不同细菌引起的菌血症的病理生理学和临床过程的差异。
我们回顾了 2000 年 5 月常规 ICU 实践中引入白细胞介素（IL）-6 血液水平快速检测以来，在八年期间连续入住大学教学医院综合 ICU 的所有患者的病历。比较不同致病细菌引起的菌血症的白细胞计数、C 反应蛋白（CRP）、IL-6 血液水平和临床病程。
本研究纳入了 259 例符合条件的患者和他们的 515 份培养阳性血样。与败血症组（n=127）相比，脓毒性休克组（n=57）的 CRP、IL-6 血液水平和死亡率显著更高（P<0.001）。515 份培养阳性血样共培养出 593 株微生物（革兰阳性菌 407 株，革兰阴性菌 176 株，真菌 10 株）。脓毒性休克组的革兰阴性菌血症发生率明显高于败血症组（P<0.001）和严重败血症组（n=75，P<0.01）。革兰阴性菌血症（n=176）的 CRP 和 IL-6 血液水平明显高于革兰阳性菌血症（n=407）（P<0.001，<0.0005）。
在伴有脓毒性休克的菌血症 ICU 患者中，革兰阴性菌血症的发生率明显高于败血症或严重败血症患者。此外，革兰阴性菌血症的 CRP 和 IL-6 水平明显高于革兰阳性菌血症。这些发现表明，在治疗菌血症患者时，应考虑不同致病微生物的宿主反应和毒力机制的差异，并且迫切需要除传统抗菌药物以外的新对策。
