creatinine in serum/plasma
Indications
- assessment of renal disease (renal function)
Reference interval
* Conversion factor mg/dL to umol/L = 88.4
Principle
Clinical significance
- serum creatinine & urinary creatinine excretion are a function of lean body mass in normal persons
- little or no response to dietary changes
- serum creatinine is higher in men than in women
- a small amount of creatinine in urine is due to tubular secretion
- serum creatinine & a 24 hour urine creatinine excretion can be used to estimate the glomerular filtration rate (GFR)
- significant loss of renal function at higher GFR may result in only small changes in serum creatinine[5]
Increases
- decreased glomerular filtration
- acute or chronic renal failure
- urinary tract obstruction
- reduced renal blood flow
- shock
- dehydration
- increases independently of glomerular filtration
- ketoacidosis: acetoacetate interferences with Jaffe reaction
- massive rhabdomyolysis
- high meat intake
- supplementary creatine
- sustained exercise
- certain pharmaceutical agents
- inhibition of proximal tubule secretion
- interference with Jaffe reaction
- amphotericin B (in vivo effect)
- kanamycin (in vivo effect)
Decreases
- debilitation
- decreased muscle mass
- low serum creatinine is associated with sarcopenia & frailty[9]
- low preoperative serum creatinine is associated with higher risk of major postoperative complications & 30 day mortality[9]
- N-acetylcysteine
- cirrhosis[5]
- exercise may cause an increased creatinine clearance*
* creatinine clearance is unreliable if the urine flow is low.
Specimen
The recommended specimen is 10 uL of serum or plasma
Serum or Plasma Specimens: Collect by standard venipuncture technique. No special patient preparation is necessary. Lithium or sodium heparin may be used as an anticoagulant for plasma specimens. Special Precautions: Potassium oxalate/sodium fluoride, citrate, & EDTA should not be used as anticoagulants. Remove serum or plasma promptly from the clot or cells. Refrigerate specimens at 2-8 degrees C if not analyzed within 4 hours, or freeze specimens at -18 degrees C if analysis is delayed beyond 48 hours. Do not use specimens obtained through catheters used to infuse hyperalimentation fluid. Urine Specimens: Collect specimens by standard laboratory procedure. Keep specimens refrigerated until analysis. Dilute each specimen 40-fold with reagent grade water (1 mL patient plus 19mL of water, then take 1 mL of this dilution & add 1 mL of water) before analysis. Multiply results by 40 to obtain the creatinine value. Dynamic range for urine CREA is 0.1 - 16.5 mg/dL.
Minimum sample size is 0.5 mL; with an optimum size of 1.0 mL or larger.
More general terms
Additional terms
Component of
- chemistry 7 panel (Chem-7 SMA7)
- chemistry 8 panel (basic metabolic panel, BMP, basic chemistry panel)
- chemistry 8 panel with ionized calcium; basic metabolic panel (BMP) with ionized calcium
- chemistry 14 panel (comprehensive metabolic panel, CMP, chem 12, SMA12, SMA20)
- creatinine clearance
- chronic kidney disease epidemiology (CKD-EPI) collaboration equation
- Modification of diet in Renal Disease (MDRD) Study equation
- protein/creatinine in serum/plasma
- carnitine/creatinine in serum/plasma
- cyclic AMP/creatinine in serum/plasma
- parathyroid panel
References
- ↑ Kodak Ektachem 700 Analyzer Operator's Manual, Kodak Clinical Products, Rochester, New York.
- ↑ Kodak Ektachem Slide Package Inserts, Kodak Clinical Products Rochester, New York.
- ↑ Kodak Ektachem Training Manual, Kodak Clinical Products, Rochester, New York.
- ↑ Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 620.
- ↑ 5.0 5.1 5.2 Medical Knowledge Self Assessment Program (MKSAP) 11, 16, 17, 18. American College of Physicians, Philadelphia 1998, 2012, 2015, 2018.
- ↑ Clinical Diagnosis & Management by Laboratory Methods, 19th edition, J.B. Henry (ed), W.B. Saunders Co., Philadelphia, PA. 1996, pg 11.
- ↑ Prescriber's Letter 9(5):28 2002
- ↑ Creatinine, Serum or Plasma Laboratory Test Directory ARUP: http://www.aruplab.com/guides/ug/tests/0020025.jsp
Panel of 11 tests Laboratory Test Directory ARUP: http://www.aruplab.com/guides/ug/tests/0020144.jsp
Panel of 9 tests Laboratory Test Directory ARUP: http://www.aruplab.com/guides/ug/tests/0020399.jsp
Panel of 15 tests Laboratory Test Directory ARUP: http://www.aruplab.com/guides/ug/tests/0020408.jsp
Panel of 6 tests Laboratory Test Directory ARUP: http://www.aruplab.com/guides/ug/tests/0020474.jsp
Creatinine, Serum or Plasma Laboratory Test Directory ARUP: http://www.aruplab.com/guides/ug/tests/0020725.jsp - ↑ 9.0 9.1 9.2 Loria A et al. Low preoperative serum creatinine is common and associated with poor outcomes after nonemergent inpatient surgery. Ann Surg 2023 Feb; 277:246. PMID: https://www.ncbi.nlm.nih.gov/pubmed/36448909 https://journals.lww.com/annalsofsurgery/Abstract/2023/02000/Low_Preoperative_Serum_Creatinine_is_Common_and.12.aspx