Bioburden Predictors of Diabetic Ulcer Complications

描述(申请人提供)：很难确定糖尿病足溃疡(DFU)的感染相关并发症。这项应用的目标是制定战略，以准确地识别可能会发展为感染相关并发症的DFU。其目的是1)确定a)高微生物负荷、b)微生物多样性和c)金黄色葡萄球菌和厌氧菌在预测无临床感染迹象的糖尿病足部溃疡中与感染相关的并发症方面的预后效果；以及2)确定组合微生物维度将在多大程度上提高任何单一维度以上的预测能力。一项前瞻性研究设计将用于观察伤口闭合前DFU中感染相关的并发症。150名患有DFU但没有临床感染迹象的患者的样本将每两周接受一次伤口生物接触评估和感染相关并发症的跟踪，直到1)伤口闭合，2)DFU相关截肢，3)失去随访，或4)六个月的数据收集结束。伤口生物负荷有三个维度：微生物负荷、微生物多样性和有毒微生物的存在。每个维度将通过定量培养用Levine‘s技术获得的拭子样本来测量。Levine的技术从深层组织层抽取液体样本，与伤口组织培养相比，已被证明是一种有效的伤口生物负荷测量方法。在每次随访期间，将收集伤口生物量的重复测量。此外，伤口恶化、骨髓炎或截肢的结果将在随访期间进行评估。ROC分析将用ROC曲线下面积(AUC)来评估预后效果。将考虑两种结果：(A)伤口闭合前伤口恶化和/或骨髓炎的发展，以及(B)伤口闭合前截肢。将使用多变量Logistic回归开发复合预测因子。这项研究的发现将改善有风险的DFU与那些没有发生并发症风险的DFU的区别。通过这种方式，资源可以更具成本效益地用于患者，对他们来说，更有力的干预可以防止不良后果。

DESCRIPTION (provided by applicant): It is difficult to identify diabetic foot ulcers (DFU) destined for infection-related complications. The objective of this application is to develop strategies to accurately identify DFUs that are likely to proceed to develop infection-related complications. The aims are to 1) determine the prognostic efficacy of a) high microbial load, b) microbial diversity, and c) Staphylococcus aureus and anaerobes based on swab cultures obtained using Levine's technique in predicting infection-related complications among diabetic foot ulcers without signs of clinical infection; and 2) Determine the extent to which combining microbiological dimensions will improve the predictive ability above any single dimension. A prospective research design will be used to observe infection-related complications among DFUs before wound closure. A sample of 150 subjects with DFUs but without signs of clinical infection will be assessed for wound bioburden and followed for infection-related complications every two weeks until 1) wound closure, 2) DFU-related amputation, 3) loss to follow-up or 4) the end of six months of data collection. Wound bioburden has three dimensions: microbial load, microbial diversity, and presence of virulent organisms. Each dimension will be measured by quantitatively culturing swab specimens obtained using Levine's technique. Levine's technique samples fluid from deep tissue layers and has been shown to be a valid measure of wound bioburden when compared to cultures of wound tissue. Repeat measures of wound bioburden will be collected during each follow-up. In addition, the outcomes of wound deterioration, osteomyelitis, or amputation will be assessed during follow-up. ROC analysis will be used to evaluate the prognostic efficacy in terms of area under the ROC curve (AUC). Two outcomes will be considered: (a) the development of wound deterioration and/or osteomyelitis before wound closure, and (b) amputation before wound closure. A composite predictor will be developed using multivariable logistic regression. The findings from this research will improve the discrimination of DFUs at-risk from those not-at-risk for developing complications. In this way, resources can be more cost efficiently directed toward patients for whom more vigorous interventions can prevent undesirable outcomes.