Wald Martin, Jeitler Valerie, Lawrenz Karin, Weninger Manfred, Pollak Arnold, Kirchner Lieselotte
Division of Neonatology and Intensive Care, Department of Pediatrics, Medical University of Vienna, Austria.
Artif Organs. 2006 Nov;30(11):888-91. doi: 10.1111/j.1525-1594.2006.00317.x.
Volutrauma caused by artificial ventilation represents a major morbidity risk for premature infants. Our working group has recently developed an innovative "split-flow ventilation" system aiming at the reduction of tidal volumes (TVs). The main problem for the practical use of this system is the fact that conventional measurements of commercially available flow sensors are distorted by the split flow. In this study, we present the first preclinical data from testing an adapted flow sensor combination recognizing the split flow. A preterm infant test lung was conventionally ventilated, modified by insertion of a split-flow line. In addition to the customary flow sensor (FS-1), a second flow sensor (FS-2) was integrated into the split-flow line, and a third (FS-3) was placed at the exit of the test lung for reference measurements. The signals of all three flow sensors were read and processed by a computer. The program was set to graphically add up flow curves 1, 2, and 3 during one ventilation loop. After 10 runs, a mean curve of FS-1+2 was calculated and compared to the mean curve of FS-3. Furthermore, the mean TV of 10 runs measured by FS-1+2 was calculated and compared with the mean TV calculated by FS-3. The summation curve FS-1+2 proved identical to the reference curve FS-3. FS-1+2 yielded a TV of 6.6 +/- 0.01 mL (inspiratory) and 6.7 +/- 0.02 mL (expiratory). The corresponding values of FS-3 were 6.5 +/- 0.20 mL and 6.6 +/- 0.09 mL, respectively. According to our results, the presented flow sensor constellation allows exact flow measurements in the experimental setting and appears suitable for usage in a split-flow ventilation circuit under clinical conditions.
人工通气引起的容积伤是早产儿发病的主要风险。我们的工作组最近开发了一种创新的“分流通气”系统，旨在减少潮气量（TVs）。该系统实际应用中的主要问题是，市售流量传感器的传统测量值会因分流而失真。在本研究中，我们展示了测试一种能识别分流的适配流量传感器组合的首批临床前数据。使用一个早产婴儿测试肺进行传统通气，并通过插入一条分流管路进行改造。除了常规的流量传感器（FS-1）外，第二个流量传感器（FS-2）被集成到分流管路中，第三个（FS-3）放置在测试肺的出口用于参考测量。所有三个流量传感器的信号由计算机读取和处理。程序设置为在一个通气回路中以图形方式将流量曲线1、2和3相加。经过10次运行后，计算出FS-1+2的平均曲线，并与FS-3的平均曲线进行比较。此外，计算出FS-1+2测量的10次运行的平均潮气量，并与FS-3计算的平均潮气量进行比较。总和曲线FS-1+2被证明与参考曲线FS-3相同。FS-1+2得出吸气潮气量为6.6±0.01 mL，呼气潮气量为6.7±0.02 mL。FS-3的相应值分别为6.5±0.20 mL和6.6±0.09 mL。根据我们的结果，所展示的数据表明，所提出的流量传感器组合在实验环境中能够进行精确的流量测量，并且似乎适用于临床条件下的分流通气回路。
