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Test Code LABF Lactate, Body Fluid

Useful For

Aid in differentiating between bacterial and viral meningitis

 

Aid in identifying increased glycolysis or hypoxia associated with bacterial meningitis, cerebral infarction, cerebral arteriosclerosis, intracranial hemorrhage, hydrocephalus, traumatic brain injury, cerebral edema, epilepsy, and inborn errors of metabolism

Method Name

Photometric, Lactate Oxidase/Peroxidase (Vitros Dry Slide)

Reporting Name

Lactate, BF

Specimen Type

Body Fluid


Specimen Required


Specimen Type: Spinal fluid

Container/Tube: Sterile container

Specimen Volume: 1 mL

Collection Instructions:

1. Centrifuge to remove any cellular material.

2. Indicate specimen source. Spinal fluid is the only acceptable source.


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Body Fluid Frozen (preferred) 30 days
  Refrigerated  14 days

Reject Due To

Hemolysis

Mild OK; Gross OK

Lipemia

Mild OK; Gross OK

Icterus

NA

Other

NA

Clinical Information

Lactate found in cerebrospinal fluid (CSF) is predominantly produced by central nervous system (CNS) glycolysis and is independent of serum lactate. Increased CSF lactate concentrations are related to increased cerebral glycolysis or hypoxia associated with bacterial meningitis, cerebral infarction, cerebral arteriosclerosis, intracranial hemorrhage, hydrocephalus, traumatic brain injury, cerebral edema, epilepsy, and inborn errors of metabolism. Lactate measurement in CSF has been proposed as a test to differentiate bacterial from viral meningitis.

Reference Values

Not applicable

Interpretation

Published studies suggest normal cerebrospinal fluid (CSF) lactate concentration is 1.1 to 2.3 mmol/L and meta-analysis of 33 studies concluded concentrations >3.9 mmol/L are suggestive of bacterial meningitis, with lower concentrations suggestive of viral meningitis.

Cautions

Cerebrospinal fluid (CSF) lactate concentrations should be interpreted in conjunction with clinical findings and other laboratory results. 

 

CSF lactate concentrations decrease after treatment with antibiotics, therefore specimens should be collected prior to initiation of antibiotics in order to differentiate bacterial from ascetic meningitis.

Clinical Reference

Tietz Textbook of Clinical Chemistry and Molecular Diagnosis. Fifth edition. Edited by CA Burtis, ER Ashwood, DE Bruns, et al. Elsevier, St. Louis, 2012

Method Description

The instrument used is a Vitros 350. Lactate in the specimen is oxidized by lactate oxidase to pyruvate and hydrogen peroxide. The generated hydrogen peroxide oxidizes the 4-aminoantipyrine, 1,7-dihydroxynaphthlaene dye system in a horseradish peroxidase-catalyzed reaction and results in a dye complex. Each mole of lactate oxidized results in 0.5 mole of the dye complex. The specimen is incubated at 37° C for 5 minutes and the intensity of the dye complex is measured spectrophotometrically at 540 nm.(Package insert: Vitros Chemistry Products Instructions for Use - LAC, Version 7.0 Ortho-Clinical Diagnostics, Inc. Rochester, NY 14626, 2012)

Day(s) and Time(s) Performed

Monday through Sunday, Continuously

Analytic Time

1 day/2 hours

Specimen Retention Time

1 day

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test has been modified from the manufacturer’s instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

83605

LOINC Code Information

Test ID Test Order Name Order LOINC Value
LABF Lactate, BF 14165-5

 

Result ID Test Result Name Result LOINC Value
LACBF Lactate, BF 14165-5
FLD19 Fluid Type 14725-6