Creatinine
| Order Code: | CRT |
| Order Form: | Laboratory Requisition |
Specimen:
Plasma
Collection Medium:
 |
| Plasma Separator Tube |
Alternate
Collection Media:
Call laboratory for additional acceptable specimen collection containers.
Minimum:
3 mL whole blood in light green top tube or 1 microtainer for pediatric
patients
Testing
Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around
Time:
2 hours (upon receipt in laboratory)
Reference Range:
Premature 0.3 - 1.0 mg/dL
Neonates 0.2 - 0.9 mg/dL
2-12 months 0.2 - 0.4 mg/dL
1-2 years 0.2 - 0.5 mg/dL
3-4 years 0.3 - 0.7 mg/dL
5-6 years 0.3 - 0.7 mg/dL
7-8 years 0.2 - 0.6 mg/dL
9-10 years 0.3 - 0.7 mg/dL
11-12 years 0.3 - 0.9 mg/dL
13-15 years 0.4 - 0.9 mg/dL
Males 16 years and older 0.6 - 1.2 mg/dL
Females 16 years and older 0.5 - 1.0 mg/dL
Note: There are gender-specific ranges only for ages 16 years and
older.
Comments:
Methodology switched from Jaffe method (colorimetric) to enzymatic
method on May 10, 2011. This switch also affected estimated glomerular
filtration rate (eGFR) calculation.
Test
Limitations:
Icterus: No significant interference up to an I index of 60
(approximate conjugated and unconjugated bilirubin concentration: 60
mg/dL).
Hemolysis: No significant interference up to an H index of 966 (approximate hemoglobin concentration: 966 mg/dL).
Lipemia (Intralipid): No significant interference up to an L index of 1000 (approximate triglycerides concentration: 2000 mg/dL). There is poor correlation between turbidity and triglycerides concentration.
Ascorbic acid < 300 mg/L (< 1.7 mmol/L) does not interfere.
Calcium dobesilate (e.g. Dexium) gives falsely low recoveries from 12.0 μmol/L (5 mg/L). Cyanokit (hydroxocobalamin) at therapeutic levels causes significantly higher results.
N-ethylglycine at therapeutic concentrations and DL-proline at concentrations > 1 mmol/L (115 mg/L) give falsely high results. No significant interference up to a creatine level of 4 mmol/L (524 mg/L).
Cephalosporin antibiotics do not affect this test. 2-Phenyl-1,3- indandion (Phenindion) at therapeutic concentrations interferes with the assay.
Hemolyzed samples from neonates, infants or adults with HbF values > 600 mg/dL interfere with the test.
In very rare cases gammopathy, in particular type IgM (Waldenström's macroglobulinemia), may cause unreliable results.
For diagnostic purposes, the results should always be assessed in conjunction with the patient's medical history, clinical examination and other findings.
Hemolysis: No significant interference up to an H index of 966 (approximate hemoglobin concentration: 966 mg/dL).
Lipemia (Intralipid): No significant interference up to an L index of 1000 (approximate triglycerides concentration: 2000 mg/dL). There is poor correlation between turbidity and triglycerides concentration.
Ascorbic acid < 300 mg/L (< 1.7 mmol/L) does not interfere.
Calcium dobesilate (e.g. Dexium) gives falsely low recoveries from 12.0 μmol/L (5 mg/L). Cyanokit (hydroxocobalamin) at therapeutic levels causes significantly higher results.
N-ethylglycine at therapeutic concentrations and DL-proline at concentrations > 1 mmol/L (115 mg/L) give falsely high results. No significant interference up to a creatine level of 4 mmol/L (524 mg/L).
Cephalosporin antibiotics do not affect this test. 2-Phenyl-1,3- indandion (Phenindion) at therapeutic concentrations interferes with the assay.
Hemolyzed samples from neonates, infants or adults with HbF values > 600 mg/dL interfere with the test.
In very rare cases gammopathy, in particular type IgM (Waldenström's macroglobulinemia), may cause unreliable results.
For diagnostic purposes, the results should always be assessed in conjunction with the patient's medical history, clinical examination and other findings.
Methodology:
Enzymatic Colorimetric
Sample
Processing:
Centrifuge at 3000 RPM for 10 minutes.
Aliquot plasma into labeled container and cap.
Aliquot plasma into labeled container and cap.
Sample
Storage:
Refrigerate.
Transport
Instructions:
Place specimen into zip-lock type bag, seal bag.
Place requisition into outside pocket of bag.
Transport in cooler with refrigerated coolant packs.
Place requisition into outside pocket of bag.
Transport in cooler with refrigerated coolant packs.
CPT Code:
82565
See also:
Creatinine-Other, Body Fluid (e.g., surgical drain, pericardial, peritoneal, peritoneal dialysis, pleural, or synovial)
Creatinine-Other, Body Fluid (e.g., surgical drain, pericardial, peritoneal, peritoneal dialysis, pleural, or synovial)
See Additional Information:
Chemistry Pediatric Reference Ranges
Chemistry Pediatric Reference Ranges