pseudohyponatraemia

Last edited 08/2022 and last reviewed 01/2023

Pseudohyponatraemia

• marked elevations of either lipids or proteins in plasma can cause artifactual decreases in serum sodium because of the larger relative proportion of plasma volume that is occupied by the excess lipids or proteins
• the increased protein or lipid will not appreciably change the total number of solute particles in solution
  • therefore the directly measured plasma osmolality will be normal
  • in pseudohyponatraemia no shifts of water occur

Reference:

• (1)Verbalis JG, Goldsmith SR, Greenberg A et al. Diagnosis, evaluation, and treatment of hyponatremia: expert panel recommendations. Am J Med 2013; 126: S1-42.