Gastmeier P, Schwab F, Behnke M, Geffers C
Institut für Hygiene und Umweltmedizin, Charité - Universitätsmedizin Berlin, Deutschland.
Anaesthesist. 2011 Oct;60(10):902-7. doi: 10.1007/s00101-011-1889-9. Epub 2011 Aug 28.
The data of the German hospital nosocomial infection surveillance system (KISS) were used to investigate the association between the frequency of blood cultures (BC) and central venous catheter associated bloodstream infection (CVC-BSI) rates in intensive care units (ICU).
A questionnaire on the frequency of BCs taken was sent to all ICUs participating in KISS and univariable and multivariable analyses were performed on the results.
A total of 223 ICUs provided data. The median number of BC pairs taken in 2006 was 60 with a huge variation from 3.2 to 680 per 1,000 patient days. The mean primary BSI rate was 0.90 per 1,000 patient days and 0.25 BSIs per 1,000 patient days were caused by coagulase negative Staphylococci (CNS). The mean CVC-BSI rate was 1.40 per 1,000 CVC days. In the univariable analysis the blood culture frequency had a significant influence on the CVC-associated BSI rate, considering either all pathogens (p=0.001) or only the subgroup of CNS-related cases (p=0.019). There was also a significant influence of the BC frequency on the CVC-BSI rate considering all pathogens (p=0.004) as well as the subgroup of CNS (p=0.018). Therefore the BC frequency was a significant factor affecting the incidence of BSI and CVC-BSI. According to the multivariable analysis an increase of the BC frequency of 100 BCs per 1,000 patient days leads to a 1.27-fold higher incidence density of CVC-BSI with a 95% confidence interval (95% CI) of 1.01-1.26. A further significant risk factor for CVC-BSI was the length of stay in the ICU with an adjusted incidence rate ratio (IRR) of 1.25 (95% CI 1.15-1.35). To have the status of an interdisciplinary ICU was a significant protective factor (IRR 0.64; 95% CI 0.45-0.92).
If an external benchmarking of ICU CVC-BSI rates is intended an adjustment according to the BC frequency is necessary. The BC frequency itself should be established as a quality indicator in intensive care.
利用德国医院感染监测系统（KISS）的数据，调查重症监护病房（ICU）血培养（BC）频率与中心静脉导管相关血流感染（CVC-BSI）发生率之间的关联。
向所有参与KISS的ICU发送关于血培养送检频率的调查问卷，并对结果进行单变量和多变量分析。
共有223个ICU提供了数据。2006年每1000个患者日采集的血培养对数中位数为60，范围差异极大，从3.2到680不等。原发性血流感染的平均发生率为每1000个患者日0.90例，每1000个患者日中有0.25例血流感染由凝固酶阴性葡萄球菌（CNS）引起。中心静脉导管相关血流感染的平均发生率为每1000个中心静脉导管日1.40例。在单变量分析中，无论考虑所有病原体（p = 0.001）还是仅考虑CNS相关病例亚组（p = 0.019），血培养频率对中心静脉导管相关血流感染率均有显著影响。考虑所有病原体（p = 0.004）以及CNS亚组（p = 0.018）时，血培养频率对中心静脉导管相关血流感染率也有显著影响。因此，血培养频率是影响血流感染和中心静脉导管相关血流感染发生率的一个重要因素。根据多变量分析，每1000个患者日血培养频率增加100次，中心静脉导管相关血流感染的发病密度会升高1.27倍，95%置信区间（95%CI）为1.01 - 1.26。中心静脉导管相关血流感染的另一个重要危险因素是在ICU的住院时间，调整后的发病率比值（IRR）为1.25（95%CI 1.15 - 1.35）。具备跨学科ICU的地位是一个重要的保护因素（IRR 0.64；95%CI 0.45 - 0.92）。
如果要对ICU中心静脉导管相关血流感染率进行外部基准比较，有必要根据血培养频率进行调整。血培养频率本身应被确立为重症监护中的一项质量指标。
