Yaacobi Nurit, Bar-Meir Maskit, Shchors Irina, Bromiker Ruben
From the Departments of *Pediatrics, †Infectious diseases, §Neonatology, and ‡Faculty of Medicine, Shaare Zedek Medical Center, the Hebrew University, Jerusalem, Israel.
Pediatr Infect Dis J. 2015 Apr;34(4):351-4. doi: 10.1097/INF.0000000000000594.
Bacteremia is a frequent complication in neonatal intensive care units. Blood cultures are the standard for the diagnosis. It is a common practice to draw small blood volumes for culture from neonates in order to prevent anemia; however, this might compromise the test sensitivity. We examined whether using 1 mL of blood in a single aerobic bottle would improve the culture yield compared with our current practice of obtaining 2 samples of 0.5 mL of blood (aerobic and anaerobic bottles).
A prospective controlled study was conducted between December 2009 and September 2010 at the neonatal intensive care unit of Shaare Zedek Medical Center, Jerusalem, Israel. Study population included newborns from whom blood cultures were obtained. A sample of 2 mL of blood from each patient was divided into a single aerobic bottle (1 mL; study sample) and into 2 aerobic and anaerobic bottles (0.5 mL each; control samples). Culture bottles were weighed before and after blood inoculation and time to positivity (TTP) was recorded.
We obtained 706 complete culture sets from 519 patients. Pathogens grew in 72 (10.2%) cultures from 37 patients. Isolation of organisms was significantly higher in the 0.5 mL control group (94.4% vs. 77.7%, P = 0.012). The TTP was similar in 0.5 mL and 1 mL aerobic bottles, but significantly longer in the anaerobic bottle.
Allocating 1 mL of blood into 2 bottles, aerobic and anaerobic, improved the yield of the culture compared with 1 mL in a single aerobic bottle.
菌血症是新生儿重症监护病房常见的并发症。血培养是诊断的标准方法。为预防贫血，从新生儿采集少量血液进行培养是常见做法；然而，这可能会降低检测灵敏度。我们研究了与目前采集两份0.5mL血液样本（需氧瓶和厌氧瓶）的做法相比，在单个需氧瓶中使用1mL血液是否能提高培养阳性率。
2009年12月至2010年9月，在以色列耶路撒冷沙雷兹德克医疗中心的新生儿重症监护病房进行了一项前瞻性对照研究。研究对象包括接受血培养的新生儿。将每位患者的2mL血液样本分为单个需氧瓶（1mL；研究样本）和两个需氧瓶及厌氧瓶（各0.5mL；对照样本）。在血液接种前后对培养瓶称重，并记录阳性时间（TTP）。
我们从519例患者中获得了706套完整的培养样本。37例患者的72份（10.2%）培养样本中培养出病原体。0.5mL对照组的微生物分离率显著更高（94.4%对77.7%，P = 0.012）。0.5mL和1mL需氧瓶中的TTP相似，但厌氧瓶中的TTP明显更长。
与在单个需氧瓶中使用1mL血液相比，将1mL血液分别注入需氧瓶和厌氧瓶可提高培养阳性率。
