Birkhamshaw Edmund, Winzor Gemma
Birmingham Heartlands Hospital, University Hospitals Birmingham NHS Foundation Trust, Bordesley Green East, Birmingham, B9 5SS, UK.
Public Health England, Public Health Laboratory Birmingham, Bordesley Green East, Birmingham, B9 5SS, UK.
Infect Prev Pract. 2019 Apr 19;1(1):100007. doi: 10.1016/j.infpip.2019.100007. eCollection 2019 Mar.
Optimising the diagnosis of bacteraemia has clinical, infection control and antimicrobial stewardship benefits. It's well documented that volume of blood received in blood culture bottles affects test sensitivity. The ability of blood cultures to detect bacteraemia is proportional to the volume of blood cultured. We undertook a period of baseline measurement and established that mean blood culture fill volume was inadequate.
The primary aim was to increase the percentage of adequately filled blood cultures (≥5ml) by 20% and increase the percentage of optimally filled bottles (8-10ml) by 10% in six months (by 1st August 2018). Our secondary aim was to increase the mean volume in blood culture bottles to 8ml (by 1 August 2018). We measured the clinical impact of this on test sensitivity by comparing blood culture positivity rate between adequately and inadequately filled bottles.
Following a period of baseline measurement we implemented three phases of plan/do/study/act (PDSA) intervention cycles (including a small test pilot cycle). Interventions were focused around user education/engagement, real time user feedback and laboratory reporting. User questionnaires were administered to investigate knowledge and practice; further informing the interventions.
RESULTS & CONCLUSION: Between 1 March - 1 August 2018 the mean volume of blood inoculated into culture bottles rose from 5ml (95% CI 4.1-6.0ml) to 7.5ml (95% CI 6.4-8.5ml). The percentage of adequately-filled (≥5ml) blood culture bottles increased from 47% to 61% (absolute increase of 14%) and the percentage of optimally-filled (≥8ml) bottles increased from 16% to 29% (absolute increase of 13%). Although our project didn't fully meet its aims, we observed a significant and sustained improvement in filling of blood culture bottles.
优化菌血症的诊断对临床、感染控制及抗菌药物管理有益。有充分文献记载，血培养瓶中所采集的血液量会影响检测灵敏度。血培养检测菌血症的能力与培养的血液量成正比。我们进行了一段时间的基线测量，发现血培养的平均填充量不足。
主要目的是在六个月内（至2018年8月1日）将充分填充的血培养瓶（≥5毫升）的百分比提高20%，并将最佳填充瓶（8 - 10毫升）的百分比提高10%。次要目的是在2018年8月1日前将血培养瓶中的平均血量增加至8毫升。我们通过比较充分填充和未充分填充的瓶子之间的血培养阳性率，来衡量这对检测灵敏度的临床影响。
在进行了一段时间的基线测量后，我们实施了三个阶段的计划/执行/研究/行动（PDSA）干预循环（包括一个小型测试试点循环）。干预措施集中在用户教育/参与、实时用户反馈及实验室报告方面。发放用户问卷以调查知识和实践情况，为干预措施提供进一步信息。
在2018年3月1日至8月1日期间，接种到培养瓶中的血液平均量从5毫升（95%置信区间4.1 - 6.0毫升）增至7.5毫升（95%置信区间6.4 - 8.5毫升）。充分填充（≥5毫升）的血培养瓶的百分比从47%增至61%（绝对增幅14%），最佳填充（≥8毫升）的瓶子的百分比从16%增至29%（绝对增幅13%）。尽管我们的项目未完全实现目标，但我们观察到血培养瓶填充情况有显著且持续的改善。
