LOINCActiveBoth

LOINC Code 16551-4: CO2 (BldC) [Moles/Vol]

16551-4 is a LOINC code used to identify CO2 (BldC) [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 BldC.

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 BldC.

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 Capillary blood
  • Carbon dioxide
  • Blood - capillary; Cap bld; Cap blood; Capillary bld; Capillary blood; Carbonic anhydride; cCO2; Chemistry; CO2; CO2 TOTAL; CO2CT; ctCO2; Finger stick; Level; Point in time; QNT; Quan; Quant; Quantitative; Random; 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.

Common synonyms

CO2 (BldC) [Moles/Vol]Carbon dioxide, total [Moles/volume] in Capillary bloodCO2 BldC-sCncCarbon dioxideCHEMCarbon Dioxide (CO2), BloodSCnc

Frequently asked questions

Code details

Code16551-4
SystemLOINC
Display nameCO2 (BldC) [Moles/Vol]
DescriptionCarbon dioxide
Short nameCO2 BldC-sCnc
ComponentCarbon dioxide
PropertySCnc
TimingPt
System (specimen)BldC
ScaleQn
ClassCHEM
Example unitsmmol/L
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0l
Last changed2.73

Consumer names

Carbon Dioxide (CO2), Blood

Part names

Carbon dioxideSCncPtBldCQnSubstance ConcentrationPoint in time (spot)Blood capillary

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 16551-4 | HealthAssure