Test Catalog

Test Id : CRT2F

Not Orderable

Creatinine, 24 Hour, Urine

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Overview

Test Catalog

Useful For
Suggests clinical disorders or settings where the test may be helpful

Normalizing urinary analytes to account for the variation in urinary concentration

Method Name
A short description of the method used to perform the test

Only orderable as part of a profile. For more information see:

-TLTE4 / Leukotriene E4, 24 Hour, Urine

-MCM24 / Mast Cell Mediators, 24 Hour, Urine

 

Enzymatic Colorimetric Assay

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Creatinine, 24 HR, U

Specimen Type
Describes the specimen type validated for testing

Urine

ORDER QUESTIONS AND ANSWERS

Question ID Description Answers
TM10F Collection Duration (h)
VL8F Urine Volume (mL)

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Only orderable as part of a profile. For more information see:

-TLTE4 / Leukotriene E4, 24 Hour, Urine

-MCM24 / Mast Cell Mediators, 24 Hour, Urine

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.

1 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Urine Frozen (preferred) 30 days
Refrigerated 30 days
Ambient 14 days

Useful For
Suggests clinical disorders or settings where the test may be helpful

Normalizing urinary analytes to account for the variation in urinary concentration

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Creatinine is formed from the metabolism of creatine and phosphocreatine, both of which are principally found in muscle. Thus, the amount of creatinine produced is, in large part, dependent upon the individual's muscle mass and tends not to fluctuate much from day-to-day.

 

Creatinine is not protein bound and is freely filtered by glomeruli. All filtered creatinine is excreted in the urine. Renal tubular secretion of creatinine contributes a small proportion of excreted creatinine. Although most excreted creatinine is derived from an individual's muscle mass, dietary protein intake, particularly of cooked meat, can contribute to urinary creatinine levels.

 

The renal clearance of creatinine provides an estimate of glomerular filtration rate.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Only orderable as part of a profile. For more information see:

-TLTE4 / Leukotriene E4, 24 Hour, Urine

-MCM24 / Mast Cell Mediators, 24 Hour, Urine

 

Normal values mg per 24 hours:

Males: 930-2955 mg/24 hours

Females: 603-1783 mg/24 hours

 

Reference values have not been established for patients who are younger than 18 years.

Interpretation
Provides information to assist in interpretation of the test results

Decreased creatinine clearance indicates decreased glomerular filtration rate. This can be due to conditions, such as progressive kidney disease, or result from adverse effect on renal hemodynamics that are often reversible, including certain drugs or from decreases in effective renal perfusion (eg, volume depletion or heart failure).

 

Increased creatinine clearance is often referred to as "hyperfiltration" and is most frequently seen during pregnancy or in patients with diabetes mellitus before diabetic nephropathy has occurred. It may also occur with large dietary protein intake.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

The reliability of 24-hour urinary creatinine determinations is, as for all timed urine collections, very dependent on accurately collected 24-hour specimens.

 

Intraindividual variability in creatinine excretion may be due to differences in muscle mass or amount of ingested meat.

 

Acute changes in glomerular filtration rate, before a steady state has developed, will alter the amount of urinary creatinine excreted.

 

Rifampicin, levodopa, and calcium dobesilate (eg, Dexium) cause artificially low creatinine results. According to Clinical and Laboratory Standards Institute guidelines, methyldopa, as tested, causes artificially low creatinine results.

 

Dicynene (etamsylate) at therapeutic concentrations may lead to falsely low results.

 

N-Ethylglycine at therapeutic concentrations and DL-proline at concentrations greater or equal to 1 mmol/L gives falsely high results.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Delaney MP, Lamb EJ. Kidney disease. In: Rifai N, Horvath AR, Wittwer CT, eds: Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:1256-1323

2. Meeusen JW, Rule AD, Voskoboev N, Baumann NA, Lieske JC. Performance of cystatin C- and creatinine-based estimated glomerular filtration rate equations depends on patient characteristics. Clin Chem. 2015;61(10):1265-1272. doi:10.1373/clinchem.2015.243030

3. Newman DJ, Price CP. Renal function and nitrogen metabolites. In: Burtis CA, Ashwood ER, eds. Tietz Textbook of Clinical Chemistry. 3rd ed. WB Saunders Company; 1999:1204-1270

4. Kasiske BL, Keane WF. Laboratory assessment of renal disease: clearance, urinalysis, and renal biopsy. In: Brenner BM, ed. The Kidney. 6th ed. WB Saunders Company; 2000:1129-1170

Method Description
Describes how the test is performed and provides a method-specific reference

This enzymatic method is based on the determination of sarcosine from creatinine with the aid of creatininase, creatinase, and sarcosine oxidase. The liberated hydrogen peroxide is measured via a modified Trinder reaction using a colorimetric indicator. Optimization of the buffer system and the colorimetric indicator enables the creatinine concentration to be quantified both precisely and specifically.(Package insert: Creatinine plus ver 2. Roche Diagnostics; V 15.0, 03/2019)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Sunday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

1 day

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

7 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their account representative. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
CRT2F Creatinine, 24 HR, U 65634-8
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
CR_AF Creatinine, 24 HR, U 2162-6
TM10F Collection Duration (h) 13362-9
VL8F Urine Volume (mL) 3167-4
CRF24 Creatinine Concentration, 24 HR, U 20624-3

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports