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.

LOINCActiveObservation

LOINC Code 54309-0: Lactate/Pyruvate (CSF) [Molar ratio]

Name: LOINC Code 54309-0: Lactate/Pyruvate (CSF) [Molar ratio]
Creator: HealthAssure Clinical Team
Published: 2026-05-25T17:13:11.347Z

54309-0 is a LOINC code used to identify Lactate/Pyruvate (CSF) [Molar ratio] 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 Lactate/Pyruvate. 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 Lactate/Pyruvate. 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: Observation

What it does not mean

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

Key facts

Lactate/Pyruvate [Molar ratio] in Cerebral spinal fluid
Lactate/Pyruvate
2-Hydroxypropanoic acid; 2-hydroxy-propionate; 2-hydroxy-propionic acid; Cerebral spinal fluid; Cerebrospinal Fl; Chemistry; Lact; Lactic acid; L-lactate; Point in time; Pyruvic acid; QNT; Quan; Quant; Quantitative; Random; Scrto; Spinal Fl; Spinal Fld; Spinal Flu; Spinal Fluid; Substance concentration ratio; Substance ratio

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 Lactate/Pyruvate (CSF) [Molar ratio] (54309-0)

Related observations and tests

SNOMED_CT 705114005high

LOINC Code System

Source: LOINC-SNOMED cooperation package

Common synonyms

Lactate/Pyruvate (CSF) [Molar ratio]Lactate/Pyruvate [Molar ratio] in Cerebral spinal fluidLactate/Pyruvate CSF-sRtoLactate/PyruvateCHEMLactate/Pyruvate, Spinal fluidSRto

Frequently asked questions

Code details

Code54309-0

SystemLOINC

Display nameLactate/Pyruvate (CSF) [Molar ratio]

DescriptionLactate/Pyruvate

Short nameLactate/Pyruvate CSF-sRto

ComponentLactate/Pyruvate

PropertySRto

TimingPt

System (specimen)CSF

ScaleQn

ClassCHEM

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.27

Last changed2.42

Consumer names

Lactate/Pyruvate, Spinal fluid

Part names

Lactate/PyruvateSRtoPtCSFQnSubstance RatioPoint 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.