Estimation of Serum Urea
Haematology lab
Miss. Tahani Al Shehri
Objective
• 1. To estimate the concentration of urea
in serum
• 2. To obtain experience in the use of
kits
Introducton
Introducton
• Urea is nitrogen compound , formed
almost solely in the liver
• From the catabolism of amino acids and
is the main excretion product of protein
metabolism
Introducton
• The concentration
of urea in the blood
serum represent
mainly a balance
between urea
formation from
protein catabolism
and urea excretion
by kidney .
Introducton
• If kidney fail ,
blood urea Conc.
Increase to high
level and toxic
condition known as
(Uremia ) will result .
• In uremia , urea
must be removed
from the blood by
clinical procedure
called “Blood Dialysis
“
Introducton
Blood Urea Nitrogen (BUN)
• Some time used as measurement of serum urea
• ½ Mwt of Urea is Nitrogen
Normal range
• Serum urea ( 10-50 ) mg/dl
• BUN ( 5- 25) mg/dl
Clinical calculator
http://www.clinicalculator.com/homepage.htm
Clinical calculator
Serum urea normally vary
depending on :
• Age ( due to change kidney function )
• Sex ( conc. are slightly higher in men )
• Diet ( protein diet
Urea )
Abnormal condition
• Causes of high Serum urea
• 1. tissue protein catabolism (-ve N balance)
This occurs in :
Fevers
Wasting disease
Thyrotoxicosis
Diabetic coma
After trauma or a major operation
Abnormal condition
• 2. Excess breakdown of blood protein
Leukemia
Release of leukocyte protein
GIT Bleeding
Hb & plasma protein can
be released in to the gut
Abnormal condition
• 3. Diminished excretion of urea
Pre-renal
Eg,
-Shock
-congestive heart
failure
-Sodium depletion
-Addison’s disease
Renal disease
Eg,
Acute Glomerulonephritis
Chronic heart failure
Sever destructive renal disease
Acute renal failure
Hepatorenal syndrom
Post-renal
Eg,
ُُ
-Enlarge prostate
Gland
-Stone
Azotemia :- Is a term used for a high •
blood serum urea concentration
Uraemia :- ( as opposed to Azotemia) •
Is the name given to the clinical •
syndrom that develops when there is
nitrogen retention due to renal failure
Low Serum urea
•
•
•
•
•
•
•
•
1.Late pregnancy Due to :
glomerluar filtration rate (GFR)
Use of N by fetus
Water retention
2. Liver disease
3.long term of protein malnutrition
Increase rate of protein anabolism
Long term replacement of blood loss with
intravenous dextran or glucose or saline
(Dilution )