From Isonatric to Isotonic Hemodialysis

Background: Isonatric hemodialysis aims at maintaining stable cellular hydration through a close control of natremia, considered a surrogate of tonicity. However, 2 methods are available to perform isonatric hemodialysis: one based on natremia derived from plasma conductivity (NaCond) and the other based on natremia measured at laboratory (NaLab). We compared the control of tonicity obtained by isonatric hemodialysis based on NaLab or NaCond. Methods: Changes in tonicity NaLab and NaCond were recorded during 55 hemodialysis sessions. Sessions were divided according to the variation of tonicity: hypotonic sessions (tonicity decrease ≥2 mOsm/kg); isotonic sessions (tonicity variation <2 mOsm/kg); hypertonic sessions (tonicity increase ≥2 mOsm/kg). Results: During isotonic hemodialysis, NaCond decreases significantly by 1 mmol/L, whereas NaLab remained stable. Conclusions: Isonatric hemodialysis based on NaLab and isonatric hemodialysis based on NaCond is to be distinguished. Isotonic hemodialysis could be performed by decreasing NaCond by 1 mmol/L or maintaining NaLab stability.

Experimental Investigations on Electrical Plasma Conductivity in a Model Spark Gap for Surge Currents

In this experimental investigation the electrical conductivity of plasma is measured during surge current using potential probes. The measurements were carried out in a narrow gap arrangement based on spark gap technology. In order to investigate the electrical conductivity during surge this model is tested using 8/20 µs surge currents according to the IEC 62475. The measured behaviour of the electrical conductivity during surge and the uncertainty of these measurements are discussed