LOINCActiveBoth

LOINC Code 2691-4: Osmolality (Periton fld) [Osmolality]

2691-4 is a LOINC code used to identify Osmolality (Periton fld) [Osmolality] 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 Observation. It is commonly used with the system or sample type Periton fld.

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 Observation. It is commonly used with the system or sample type Periton fld.

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

  • Osmolality of Peritoneal fluid
  • Observation
  • Ascites; Ascitic fluid; Ascitis; Chemistry; Osmo; Osmolality; Peritoneal fluid; Point in time; Prt; QNT; Quan; Quant; Quantitative; Random

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

Osmolality (Periton fld) [Osmolality]Osmolality of Peritoneal fluidOsmolality PrtObservationCHEMOsmolality, Peritoneal fluidOsmol

Frequently asked questions

Code details

Code2691-4
SystemLOINC
Display nameOsmolality (Periton fld) [Osmolality]
DescriptionObservation
Short nameOsmolality Prt
ComponentObservation
PropertyOsmol
TimingPt
System (specimen)Periton fld
ScaleQn
ClassCHEM
Example unitsmOsm/kg
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0
Last changed2.79

Consumer names

Osmolality, Peritoneal fluid

Part names

ObservationOsmolPtPeriton fldQnOsmolalityPoint in time (spot)Peritoneal 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.

LOINC Code 2691-4 | HealthAssure