Institute of Medical Technologies and Health Management, Joanneum Research GmbH, Elisabethstrasse 11a, 8010, Graz, Austria.
Biomed Microdevices. 2010 Jun;12(3):399-407. doi: 10.1007/s10544-010-9396-3.
Glycemic control of intensive care patients can be beneficial for this patient group but the continuous determination of their glucose concentration is challenging. Current continuous glucose monitoring systems based on the measurement of interstitial fluid glucose concentration struggle with sensitivity losses, resulting from biofouling or inflammation reactions. Their use as decision support systems for the therapeutic treatment is moreover hampered by physiological time delays as well as gradients in glucose concentration between plasma and interstitial fluid. To overcome these drawbacks, we developed and clinically evaluated a system based on microdialysis of whole blood. Venous blood is heparinised at the tip of a double lumen catheter and pumped through a membrane based micro-fluidic device where protein-free microdialysate samples are extracted. Glucose recovery as an indicator of long term stability was studied in vitro with heparinised bovine blood and remained highly stable for 72 h. Clinical performance was tested in a clinical trial in eight healthy volunteers undergoing an oral glucose tolerance test. Glucose concentrations of the new system and the reference method correlated at a level of 0.96 and their mean relative difference was 1.9 +/- 11.2%. Clinical evaluation using Clark's Error Grid analysis revealed that the obtained glucose concentrations were accurate and clinically acceptable in 99.6% of all cases. In conclusion, results of the technical and clinical evaluation suggest that the presented device delivers microdialysate samples suitable for accurate and long term stable continuous glucose monitoring in blood.
重症监护患者的血糖控制对这类患者群体有益，但连续测定其血糖浓度具有挑战性。目前基于间质液葡萄糖浓度测量的连续血糖监测系统存在灵敏度损失的问题，这是由于生物污垢或炎症反应所致。由于生理时滞以及血浆和间质液之间的葡萄糖浓度梯度，这些系统在作为治疗治疗的决策支持系统方面受到阻碍。为了克服这些缺点，我们开发并临床评估了一种基于全血微透析的系统。在双腔导管的尖端用肝素化静脉血，并通过基于膜的微流体装置泵送，在那里提取无蛋白的微透析样品。体外用肝素化牛血研究了葡萄糖回收率作为长期稳定性的指标，结果表明其在 72 小时内仍高度稳定。在 8 名接受口服葡萄糖耐量试验的健康志愿者中进行的临床试验中测试了临床性能。新系统和参考方法的葡萄糖浓度相关性达到 0.96 的水平，其平均相对差异为 1.9 +/- 11.2%。使用 Clark 的误差网格分析进行临床评估表明，在所有情况下，所获得的葡萄糖浓度均准确且在临床可接受范围内，占 99.6%。总之，技术和临床评估的结果表明，所提出的设备可提供适用于血液中准确和长期稳定的连续血糖监测的微透析样品。
