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.

LOINCBoth

LOINC Code 74938-2: Lidocaine trough [Mass/Vol]

Name: LOINC Code 74938-2: Lidocaine trough [Mass/Vol]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:55.156Z

74938-2 is a LOINC code used to identify Lidocaine trough [Mass/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 Lidocaine^trough. It is commonly used with the system or sample type Ser/Plas.

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 Lidocaine^trough. It is commonly used with the system or sample type Ser/Plas.

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: DEPRECATED
Order vs observation: Both

What it does not mean

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

Key facts

Deprecated Lidocaine [Mass/volume] in Serum or Plasma --trough
Lidocaine^trough
c232; c251; CLID; DRUG/TOXICOLOGY; Drugs; Level; Mass concentration; Pl; Plasma; Plsm; Point in time; Pre; Predose; Pre-dose; QNT; Quan; Quant; Quantitative; Random; SerP; SerPl; SerPlas; Serum; Serum or plasma; SR; Xylocaine

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

Lidocaine trough [Mass/Vol]Deprecated Lidocaine [Mass/volume] in Serum or Plasma --troughDeprecated Lidocain Trough SerPl-mCncLidocaine^troughDRUG/TOXLidocaine trough, BloodMCnc

Frequently asked questions

Code details

Code74938-2

SystemLOINC

Display nameLidocaine trough [Mass/Vol]

DescriptionLidocaine^trough

Short nameDeprecated Lidocain Trough SerPl-mCnc

ComponentLidocaine^trough

PropertyMCnc

TimingPt

System (specimen)Ser/Plas

ScaleQn

ClassDRUG/TOX

Example unitsmg/L

StatusDEPRECATED

Order/ObservationBoth

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.48

Last changed2.54

Consumer names

Lidocaine trough, Blood

Part names

Lidocaine^troughMCncPtSer/PlasQnMass ConcentrationPoint in time (spot)Serum or Plasma

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.