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.

LOINCActive

LOINC Code 19891-1: Carbon dioxide [Partial pressure] in Exhaled gas --at end expiration

Name: LOINC Code 19891-1: Carbon dioxide [Partial pressure] in Exhaled gas --at end expiration
Creator: HealthAssure Clinical Team
Published: 2026-05-21T11:17:28.199Z

19891-1 is a LOINC code used to identify Carbon dioxide [Partial pressure] in Exhaled gas --at end expiration 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^at end expiration. It is commonly used with the system or sample type Exhl gas.

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 Carbon dioxide^at end expiration. It is commonly used with the system or sample type Exhl gas.

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

What it does not mean

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

Key facts

Carbon dioxide [Partial pressure] in Exhaled gas --at end expiration
Carbon dioxide^at end expiration
Breath; Carbonic anhydride; cO2; End tidal pCO2; ETCO2; ExG; Exhaled gas; Exhaled gas (=breath); Exp; Gases; Lung; Partial pressure; PCO2; PetCO2; Point in time; PULMONARY; Pulmonology; QNT; Quan; Quant; Quantitative; Random; Respiratory

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

Carbon dioxide [Partial pressure] in Exhaled gas --at end expirationpCO2 end exp ExGCarbon dioxide^at end expirationPULMPPresPtExhl gas

Frequently asked questions

Code details

Code19891-1

SystemLOINC

Display nameCarbon dioxide [Partial pressure] in Exhaled gas --at end expiration

DescriptionCarbon dioxide^at end expiration

Short namepCO2 end exp ExG

ComponentCarbon dioxide^at end expiration

PropertyPPres

TimingPt

System (specimen)Exhl gas

ScaleQn

ClassPULM

Example unitsmm Hg

StatusACTIVE

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released1.0l

Last changed2.56

Part names

Carbon dioxide^at end expirationPPresPtExhl gasQnPartial pressurePoint in time (spot)Exhaled gas

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.