Serum Creatinine

A serum creatinine test measures the level of creatinine in your blood and provides an estimate of how well your kidneys filter (glomerular filtration rate).

Also Known As:  Creat, Blood Creatinine, Serum Creatinine, 

Panel Tests:  Urea, Blood Urea Nitrogen, Creatinine, Calcium, Phosphorus, Albumin, Magnesium, Total Protien, Electrolytes,

Why Get Tested:

• Creatinine level is done to assess kidney function.
• creatinine can be advised to see any effect of blood pressure or diabetes on the kidney.
• Creatinine is advised to monitor renal diseases.
• Creatinine may be measured in amniotic fluid to assess the gestational (fetal) age and (fetal-maturity index), and cephalosporins.

When To Get Tested?

• Routinely as part of a comprehensive metabolic panel (CMP) or basic metabolic panel (BMP) when you have a health exam
• When your have signs and symptoms that may be due to kidney disease or damage or when you have a condition that may affect your kidneys and/or be worsened by kidney dysfunction
• At intervals to monitor treatment for kidney disease or kidney function while on certain medications

Normal Values:

• Male = 0.3 to 1.0 mg/dl
• Female = 0.3 to 1.0 mg/dl

Increased creatinine level is seen in:

• Renal function impairment both acute and chronic diseases.
• Postrenal obstruction of urine.
• Decrease in the blood perfusion because of any reason.
• Gigantism and Acromegaly.
• Injury to the muscles (Rhabdomyolysis).
• Myasthenia gravis.
• Poliomyelitis.
• Muscular dystrophy.
• Dehydration due to loss of body fluids.
• May be seen in pregnancy during eclampsia and preeclampsia.

Decreased creatinine level is seen in:

1. Old-age.
2. Decreased muscle mass.
3. Pregnancy especially in the first and second trimester.
4. Advanced and severe liver disease.
5. inadequate dietary intake.

1. Pre-renal factors for raised serum creatinine are:
   • Congestive heart failure.
   • Shock.
   • Salt and water depletion due to:
     • Vomiting.
     • Diarrhea.
     • GIT fistulas.
     • Increased use of diuretics.
     • Uncontrolled diabetes mellitus.
     • Diabetes insipidus.
     • Excessive sweating (decreased salt intake).
2. Renal factors for raised serum creatinine are:
   • Damage to:
     • Glomerulus.
     • Tubules.
     • Interstitial tissue.
     • Blood vessels.
3. Post-renal factors for raised serum creatinine are:
   • Benign prostatic hyperplasia.
   • Neoplasia compressing the ureter.
   • Calculi obstructing the ureter.
   • Congenital abnormalities obstructing or compressing the ureter.

Interfering factors:

1. Ascorbic acid can increase creatinine levels.
2. A diet high in protein like meat can increase the level.

The critical value is >4.0 mg/dL .