Jaffrin Michel Y, Fenech Marianne, de Fremont Jean-François, Tolani Michel
UMR CNRS 6600, Technical University of Compiegne, France.
ASAIO J. 2002 May-Jun;48(3):326-33. doi: 10.1097/00002480-200205000-00021.
Bioimpedance spectroscopy (BIS) permits evaluation of extra- and intracellular fluid volumes in patients. We wished to examine whether this technique, used in combination with hematocrit measurement, can reliably monitor fluid transfers during dialysis. Ankle to wrist BIS measurements were collected during 21 dialysis runs while hematocrit was continuously monitored in the blood line by an optical device. Extracellular (ECW) and intracellular (ICW) water volumes were calculated using Hanai's electrical model of suspensions. Plasma volume variations were calculated from hematocrit, and changes in interstitial volume were calculated as the difference between ECW and plasma volume changes. Because accuracy of ICW was too low, changes in ICW were calculated as the difference between ultrafiltered volume and ECW changes. Total body water (TBW) volumes calculated pre- and postdialysis were, respectively, 3.25+/-3.2 and 1.95+/-2.5 liters lower on average than TBW given by Watson et al.'s correlation. Average decreases in fluid compartments expressed as percentage of ultrafiltered volume were as follows: plasma, 18%; interstitial, 28%, and ICW, 54%. When the ultrafiltered volume was increased in a patient in successive runs, the relative contributions of ICW and interstitial fluid were augmented so as to reduce the relative drop in plasma volume.
生物电阻抗光谱法（BIS）可用于评估患者细胞外液和细胞内液的容量。我们希望研究该技术与血细胞比容测量相结合时，能否可靠地监测透析过程中的液体转移情况。在21次透析过程中收集了从脚踝到手腕的生物电阻抗光谱测量数据，同时通过光学设备持续监测血路中的血细胞比容。使用Hanai的悬浮液电学模型计算细胞外液（ECW）和细胞内液（ICW）的容量。根据血细胞比容计算血浆容量变化，间质容量变化通过细胞外液变化与血浆容量变化之差来计算。由于细胞内液的准确性过低，细胞内液的变化通过超滤量与细胞外液变化之差来计算。透析前后计算的总体液（TBW）容量平均分别比Watson等人相关性计算的总体液低3.25±3.2升和1.95±2.5升。以超滤量的百分比表示的各体液腔室平均减少量如下：血浆18%；间质28%，细胞内液54%。当在连续几次透析中增加患者的超滤量时，细胞内液和间质液的相对贡献增加，从而减少血浆容量的相对下降。
