Annals of clinical biochemistry
-
Ann. Clin. Biochem. · Jan 2002
Comparative StudyEffect of low protein concentration on serum sodium measurement: pseudohypernatraemia and pseudonormonatraemia!
The effect of high concentrations of protein or lipid on the measurement of plasma sodium by indirect ion selective electrode (ISE) causing pseudohyponatraemia and pseudonormonatraemia is well described. The effect of a low total protein concentration, however, has not been described. ⋯ There were approximately equal numbers of samples with a protein concentration less than 50 g/L (1.3%) as samples with a protein concentration greater than 80 g/L (1.3%). The frequency of erroneous sodium results owing to the use of an indirect ISE was less in hypoproteinaemic (2%) than in hyperproteinaemic (20%) samples.