Osmolality, Serum

Update Type: Test Resumed

Test Updated: 01/10/2024

Test Overview

Test Methodology

Freezing Point

Test Usage

Evaluation of electrolyte balance, hyperosmolar status and hydration status.

Reference Range *

269 - 298 mOsm/kg

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Details

Days Set Up

Daily, 24 hours

Analytic Time

2 hours

Soft Order Code

OSMO

MiChart Code

Osmolality, Serum

Synonyms

Laboratory

Chemical Pathology

Section

Automation

STAT Availability

STAT requests for this test will be performed on a STAT basis (supervisory staff approval is not required).

Specimen Requirements

Collection Instructions

Collect blood in SST or red top tube. Centrifuge, aliquot serum into a plastic vial and refrigerate.

Alternate Specimen

Sodium or lithium heparin acceptable. [4/99]

Normal Volume

0.5 mL serum

Minimum Volume

0.25 mL serum

Billing

CPT Code

83930

Fee Code

20740

LOINC

2692-2