Olsen Margaret A, Krauss Melissa, Agniel Denis, Schootman Mario, Gentry Clare N, Yan Yan, Damiano Ralph J, Fraser Victoria J
Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri 63110-1093, USA.
Clin Infect Dis. 2008 May 15;46(10):1537-46. doi: 10.1086/587672.
Mortality attributable to bloodstream infection (BSI) is still controversial. We studied the impact of BSI on mortality after coronary artery bypass surgery, including the specific impact of different etiologic organisms.
Our cohort consisted of 4515 patients who underwent coronary artery bypass procedures at a university hospital from 1996 through 2004. We used Society of Thoracic Surgery data supplemented with laboratory and infection control data. Mortality dates were identified using Society of Thoracic Surgery data and the Social Security Death Index. BSI within 90 days after surgery was defined by a positive blood culture result. Cox proportional hazards and propensity score models were used to analyze the association between BSI and mortality.
Patients with BSI had a 4.2-fold increased risk of death (95% confidence interval [CI], 3.0-5.9) 2-90 days after coronary artery bypass surgery, compared with uninfected patients. The risk of death was higher among patients with BSI due to gram-negative bacteria (hazard ratio [HR], 6.8; 95% CI, 3.9-12.0) and BSI due to Staphylococcus aureus (HR, 7.2; 95% CI, 3.3-15.7) and lowest among patients with BSI caused by gram-positive bacteria other than S. aureus (HR, 2.2; 95% CI, 1.1-4.6). The risk of death was highest among patients who developed BSI but had the lowest likelihood of infection (HR, 10.0; 95% CI, 3.5-28.8) and was lowest among patients who developed BSI but had the highest likelihood of infection (HR, 2.3; 95% CI, 1.2-4.6).
BSIs due to gram-negative bacteria and BSIs due to S. aureus contributed significantly to mortality. Mortality attributable to BSI was highest among patients predicted to be least likely to develop infection and was lowest among severely ill patients who were most likely to develop infection. BSI appears to be an important contributor to death after coronary artery bypass surgery, particularly among the healthiest patients.
血流感染（BSI）所致死亡率仍存在争议。我们研究了BSI对冠状动脉搭桥术后死亡率的影响，包括不同病原体的具体影响。
我们的队列由1996年至2004年在一家大学医院接受冠状动脉搭桥手术的4515例患者组成。我们使用了胸外科协会的数据，并补充了实验室和感染控制数据。使用胸外科协会数据和社会保障死亡指数确定死亡日期。术后90天内的BSI由血培养结果阳性定义。采用Cox比例风险模型和倾向评分模型分析BSI与死亡率之间的关联。
与未感染患者相比，冠状动脉搭桥术后2至90天内发生BSI的患者死亡风险增加4.2倍（95%置信区间[CI]，3.0 - 5.9）。革兰氏阴性菌所致BSI患者（风险比[HR]，6.8；95%CI，3.9 - 12.0）和金黄色葡萄球菌所致BSI患者（HR，7.2；95%CI，3.3 - 15.7）的死亡风险较高，而除金黄色葡萄球菌外的革兰氏阳性菌所致BSI患者的死亡风险最低（HR，2.2；95%CI，1.1 - 4.6）。发生BSI但感染可能性最低的患者死亡风险最高（HR，10.0；95%CI，3.5 - 28.8），而发生BSI但感染可能性最高的患者死亡风险最低（HR，2.3；95%CI，1.2 - 4.6）。
革兰氏阴性菌所致BSI和金黄色葡萄球菌所致BSI对死亡率有显著影响。在预计感染可能性最小的患者中，BSI所致死亡率最高，而在最有可能发生感染的重症患者中，BSI所致死亡率最低。BSI似乎是冠状动脉搭桥术后死亡的重要原因，尤其是在最健康的患者中。
