Creatinine
Synonyms
Why do we do this test?
1. Serum creatinine assess renal function
2. Urine creatinine used as the marker for adequacy for timed collection
3. For the calculation of creatinine clearance
4. Calculating fractional excretion
5. Analyte to creatinine ratio in spot samples
6. In ascitic fluid to assess the urine leakage
Specimen Type
Serum, Plasma (EDTA), Plasma (Li Heparin), Urine (spot/ timed collection), Body Fluid
Instructions for specimen collection & Patient preparation
1. Better if it is done following overnight fasting
2. Instructions for complete collection for timed collections
Specimen transportation & Processing
Specimen storage & stability
Transport in room temperature
Storage 7 days in 2 - 8°C
3 months -20°C
Specimen storage duration
Reference Intervals & Target Values
Depends on the assay
Typically - Males 60 - 120 micro moles/L
Female 55 - 100 micro moles/L
Critical Limits
Possible Pre-analytical Errors
Spuriously high values following heavy meat meals and in persons with high muscle mass (athletes).
Possible Analytical Errors
1. In jaffe reaction - in modified kinetic reactions interference is minimal with the commonly mentioned non-creatinine chromogens like ketone and protein
Bilurubin negative interference
Antibiotics like cephalosporin and streptomycin and ascobic acid give positive interference
2. In enzymetic assay, negative interference reported with Bilurubin, haemiglobin and dopamine
Available Government Laboratories
Yes
Recommended turnaround time
1 - 2 hours

Test Method
Jaffe kinetic - colourimetry, Enztmetic

Documentation

References

Last Updated : 2020-09-23 04:35:01

 

 

 

Affiliations

         

College of Chemical Pathologists of Sri Lanka

No.112, Model Farm Road, Colombo 08.  Hotline : +94 76 7044871  Email : colchempath@gmail.com

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