Zhang Jingjing, Burr Renee A, Sheth Heena S, Piraino Beth
Clin Nephrol. 2016 Sep;86(9):141-6. doi: 10.5414/CN108633.
Data on hemodialysis (HD)-related organism specific bacteremia rates by type of access over an extended period are scant in the literature. Using a registry data base we examined all positive blood cultures by organisms for each type of HD access over 14 years.
The IRB-approved registry data collection of prevalent patients at our HD unit from 1/1/1999 through 12/31/2012 was analyzed. All positive blood cultures were recorded and expressed as episodes/1,000 days by access type: arteriovenous fistula (AVF), arteriovenous graft (AVG), and central venous catheter (CVC).
The rate of positive blood cultures in patients with CVCs was 1.86/1,000 days and was much higher than in patients with an AVF (0.08/1,000 days, p < 0.001) or an AVG (0.31/1,000 days, p < 0.002). There was considerable fluctuation in the bacteremia rate in CVCs with a spike during 2004 - 2008, due predominately to coagulase-negative staphylococcus (CNS) bacteremia. The rate subsequently decreased after retraining of staff. The exit site infection (ESI) rate of CVCs was low, suggesting this was not contributing to the cause of the increase rate of CNS bacteremia. Those patients using a CVC had a markedly increased risk of multiple episodes compared to those using an AVF. Bacteremia with Pseudomonas, polymicrobial, and fungal organisms occurred only in those with a CVC.
The frequency and type of positive blood culture in HD patients are highly associated with type of access used. The high rate of CNS bacteremia with CVC in conjunction with low ESI rate suggests that contamination at the time of accessing the catheter may be the problem. Staff training was followed by a decrease in infection rates. Trending organism-specific bacteremia infection rates in HD units may provide important clues to bacteremia causality and thus prevention.
长期以来，关于不同类型血管通路的血液透析（HD）相关特定病原体菌血症发生率的文献资料较少。我们利用一个登记数据库，对14年间每种HD血管通路的所有血培养阳性结果按病原体进行了检查。
分析了经机构审查委员会批准的、收集自1999年1月1日至2012年12月31日期间在我们血液透析单位的现患患者的登记数据。记录所有血培养阳性结果，并按血管通路类型（动静脉内瘘（AVF）、动静脉移植物（AVG）和中心静脉导管（CVC））表示为每1000天的发作次数。
使用CVC的患者血培养阳性率为1.86/1000天，远高于使用AVF的患者（0.08/1000天，p<0.001）或使用AVG的患者（0.31/1000天，p<0.002）。CVC的菌血症发生率有相当大的波动，在2004 - 2008年期间出现峰值，主要是由于凝固酶阴性葡萄球菌（CNS）菌血症。在对工作人员进行再培训后，该发生率随后下降。CVC的出口部位感染（ESI）率较低，表明这不是CNS菌血症发生率增加的原因。与使用AVF的患者相比，使用CVC的患者发生多次发作的风险明显增加。假单胞菌属、多种微生物和真菌性菌血症仅发生在使用CVC的患者中。
HD患者血培养阳性的频率和类型与所使用的血管通路类型高度相关。CVC的CNS菌血症发生率高且ESI率低表明，导管穿刺时的污染可能是问题所在。工作人员培训后感染率下降。监测HD单位特定病原体的菌血症感染率可能为菌血症的病因及预防提供重要线索。
