Along the decades of haemodialysis, there had many knowledge accumulated concerning the cardiovascular stability. Nursing compromises always the observation of the patients. This is you never come out. Today the number of patient one nurse has to treat had increase because of economic reasons. So there is much work to do for the nurses and the risk concerning a severe blood pressure had increased. All clinical points to assess to real dry weight are valid in the future. But in practice, this has difficulties: If you ask two different doctors concerning the dry weight of one single and individual patient, you definitely will get three answers…
Approaching to this theme, an overview of the different fluid compartments will be helpful. A 70 kg human has 40 l total body water. 2/3 of this (>25 l) are the intra-cellular volume, 1/3 (15 l) is the extracellular volume. Blood volume consists of both: The RBC’s belong to the intra-cellular Volume, the serum compart. In case of an underfilling there happens a poor cardiovascular state with the danger of a blood pressure decrease (in worst case even a breakdown of the circulation) or muscle-cramps by too much ultrafiltration. Ultrafiltration is only reasonable when water (from over-hydration) is present. Cardio-vascular stability you will reach, when you prevent the under-filling (> the much reduced flow from the interstitial compartment into the serum compartment).
Omics Journals 