1] Department of Renal Medicine and Research, Manchester Institute of Nephrology and Transplantation, Manchester, UK [2] School of Biomedicine, University of Manchester, Manchester, UK.
Kidney Int. 2013 Nov;84(5):980-8. doi: 10.1038/ki.2013.208. Epub 2013 Jun 5.
The kidneys and the interstitial compartment play a vital role in body fluid regulation. The latter may be significantly altered in renal dysfunction, but experimental studies are lacking. To help define this we measured the subcutaneous interstitial pressure, bioimpedance volumes, and edema characteristics in 10 healthy subjects and 21 patients with obvious edema and chronic kidney disease (CKD). Interstitial edema was quantified by the time taken for a medial malleolar thumb pit to refill and termed the edema refill time. Interstitial pressure was significantly raised in CKD compared to healthy subjects. Total body water (TBW), extracellular fluid volume (ECFV), interstitial fluid volume, the ratio of the ECFV to the TBW, and segmental extracellular fluid volume were raised in CKD. The ratio of the ECFV to the TBW and the interstitial fluid volume were the best predictors of interstitial pressure. Significantly higher interstitial pressures were noted in edema of 2 weeks or less duration. A significant nonlinear relationship defined interstitial pressure and interstitial fluid volume. Edema refill time was significantly inversely related to interstitial pressure, interstitial compartment volumes, and edema vintage. Elevated interstitial pressure in CKD with obvious edema is a combined function of accumulated interstitial compartment fluid volumes, edema vintage, and tissue mechanical properties. The edema refill time may represent an important parameter in the clinical assessment of edema, providing additional information about interstitial pathophysiology in patients with CKD and fluid retention.
肾脏和细胞外间质在体液调节中起着至关重要的作用。后者在肾功能障碍时可能会发生显著改变，但目前缺乏相关的实验研究。为了更好地定义这一概念，我们测量了 10 名健康受试者和 21 名明显水肿和慢性肾脏病（CKD）患者的皮下细胞外间质压力、生物阻抗体积和水肿特征。通过测量内侧踝拇指凹陷恢复的时间来量化细胞外间质水肿，并将其称为水肿恢复时间。与健康受试者相比，CKD 患者的细胞外间质压力显著升高。与健康受试者相比，CKD 患者的总体液量（TBW）、细胞外液量（ECFV）、细胞外间质液量、ECFV 与 TBW 的比值以及节段性细胞外液量均升高。ECFV 与 TBW 的比值和细胞外间质液量是细胞外间质压力的最佳预测因子。持续时间为 2 周或更短的水肿患者的细胞外间质压力明显更高。细胞外间质压力和细胞外间质液量之间存在显著的非线性关系。水肿恢复时间与细胞外间质压力、细胞外间质体积和水肿持续时间呈显著负相关。CKD 伴明显水肿患者的细胞外间质压力升高是细胞外间质液体积积累、水肿持续时间和组织力学特性的综合作用。水肿恢复时间可能是水肿临床评估中的一个重要参数，为 CKD 患者和液体潴留患者的细胞外间质病理生理学提供了额外的信息。
