Mechanisms of oedema in nephrotic syndrome: Old theories and new ideas

Abstract

To summarize, the asymmetry of volume expansion, which has been traditionally attributed to the decrease in plasma oncotic pressure, is more likely due to an alteration of the capillary hydraulic conductivity, possibly linked to functional changes at the level of intercellular junctions. The low plasma oncotic pressure does not unbalance the transcapillary oncotic gradient and cannot be considered as a determining factor in oedema generation or as a resistance factor for oedema resorption. Therefore, diuretics preventing renal sodium retention remain the cornerstone of the treatment of nephrotic oedema. Accordingly, the association of amiloride and furosemide provides a powerful treatment allowing progressive removal of oedema from nephrotic patients [37].