Pseudohyponatremia is mitigated by which method?

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Multiple Choice

Pseudohyponatremia is mitigated by which method?

Pseudohyponatremia happens because indirect measurements assume a constant plasma water fraction. If there’s a large non-aqueous solid fraction from high lipids or proteins, indirect ISE ends up diluting the sample and interpreting the reduced aqueous Na+ concentration as true hyponatremia. The fix is to measure sodium in undiluted plasma water, which direct ion-selective electrode (ISE) measurements do. Direct ISE assesses the sodium activity in the actual aqueous phase of the serum without relying on the plasma’s water fraction, so it isn’t distorted by excessive lipids or proteins. Temperature correction isn’t relevant to this artifact, and diluting the sample would only worsen the error in indirect measurements. Hence, direct ISE measurements best mitigate pseudohyponatremia.

Pseudohyponatremia happens because indirect measurements assume a constant plasma water fraction. If there’s a large non-aqueous solid fraction from high lipids or proteins, indirect ISE ends up diluting the sample and interpreting the reduced aqueous Na+ concentration as true hyponatremia. The fix is to measure sodium in undiluted plasma water, which direct ion-selective electrode (ISE) measurements do. Direct ISE assesses the sodium activity in the actual aqueous phase of the serum without relying on the plasma’s water fraction, so it isn’t distorted by excessive lipids or proteins. Temperature correction isn’t relevant to this artifact, and diluting the sample would only worsen the error in indirect measurements. Hence, direct ISE measurements best mitigate pseudohyponatremia.

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