What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveBoth

LOINC Code 13540-0: CO2 (CSF) [Moles/Vol]

Name: LOINC Code 13540-0: CO2 (CSF) [Moles/Vol]
Creator: HealthAssure Clinical Team
Published: 2026-05-25T17:13:11.347Z

13540-0 is a LOINC code used to identify CO2 (CSF) [Moles/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 Carbon dioxide. It is commonly used with the system or sample type CSF.

Reviewed by HealthAssure Clinical TeamUpdated 25 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 Carbon dioxide. It is commonly used with the system or sample type CSF.

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

Carbon dioxide, total [Moles/volume] in Cerebral spinal fluid
Carbon dioxide
Confirmatory test for paroxysmal nocturnal hemoglobinuria (pnh)
Carbonic anhydride; cCO2; Cerebral spinal fluid; Cerebrospinal Fl; Chemistry; CO2; CO2 TOTAL; CO2CT; ctCO2; Level; Lung; Neuro; Neurology; Point in time; Pulmonary; Pulmonology; QNT; Quan; Quant; Quantitative; Random; Respiratory; Spinal Fl; Spinal Fld; Spinal Flu; Spinal Fluid; Substance concentration; tCO2

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.

Related SNOMED CT concepts

705114005SNOMED CT mapping for CO2 (CSF) [Moles/Vol] (13540-0)

Related observations and tests

SNOMED_CT 705114005high

LOINC Code System

Source: LOINC-SNOMED cooperation package

Common synonyms

CO2 (CSF) [Moles/Vol]Carbon dioxide, total [Moles/volume] in Cerebral spinal fluidCO2 CSF-sCncCarbon dioxideCHEMCarbon Dioxide (CO2), Spinal fluidSCnc

Frequently asked questions

Code details

Code13540-0

SystemLOINC

Display nameCO2 (CSF) [Moles/Vol]

DescriptionCarbon dioxide

Short nameCO2 CSF-sCnc

ComponentCarbon dioxide

PropertySCnc

TimingPt

System (specimen)CSF

ScaleQn

ClassCHEM

Example unitsmmol/L

StatusACTIVE

Order/ObservationBoth

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released1.0k

Last changed2.34

Consumer names

Carbon Dioxide (CO2), Spinal fluid

Part names

Carbon dioxideSCncPtCSFQnSubstance ConcentrationPoint in time (spot)Cerebral spinal fluid

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.