LOINCActiveBoth

LOINC Code 82812-9: Sodium (RBC) [Mass/Vol]

82812-9 is a LOINC code used to identify Sodium (RBC) [Mass/Vol] in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Sodium. It is commonly used with the system or sample type RBC.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Sodium. It is commonly used with the system or sample type RBC.

When is it used?

  • Used in lab systems, EHRs, and clinical data exchange.
  • May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
  • Status: ACTIVE
  • Order vs observation: Both

What it does not mean

  • The code identifies the observation or test, not the actual result.

Key facts

Sodium [Mass/volume] in Red Blood Cells
Sodium
Measurement of intracellular sodium is performed in concert with the intracellular measurement of potassium. Intracellular potassium is a marker for the development of hypertension. The measurement is based on the fact that intracellular sodium is very low compared to plasma sodium. When the cells are lysed in order to measure the intracellular potassium, the hematocrit of the sample is determined by the dilution of the plasma sodium by the now free intracellular sodium. (http//pubs.acs.org/doi/pdf/10.1021/ac900776d)
Chemistry; Erythrocytes; Level; Mass concentration; Na; Na+; Point in time; QNT; Quan; Quant; Quantitative; Random; Red blood cells; Red blood corpusles

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Sodium (RBC) [Mass/Vol]Sodium [Mass/volume] in Red Blood CellsSodium RBC-mCncSodiumCHEMSodium, Red blood cellsMCnc

Frequently asked questions

Code details

Code82812-9
SystemLOINC
Display nameSodium (RBC) [Mass/Vol]
DescriptionSodium
Short nameSodium RBC-mCnc
ComponentSodium
PropertyMCnc
TimingPt
System (specimen)RBC
ScaleQn
ClassCHEM
Example unitsmg/L
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.58
Last changed2.58

Consumer names

Sodium, Red blood cells

Part names

SodiumMCncPtRBCQnMass ConcentrationPoint in time (spot)Red Blood Cells

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

LOINC Code 82812-9 | HealthAssure