This document discusses renal function tests. It begins by outlining the objectives of renal function tests which are to detect possible renal damage, assess severity, observe progress of renal disease, and monitor safe drug use. It then discusses causes of kidney disorders which can be pre-renal, renal, or post-renal. The main tests of renal function described are urine examination, tests of excretory function like creatinine clearance, and estimating blood urea nitrogen and serum creatinine levels. The document provides details on how to perform and interpret these tests.

1. RENAL FUNCTION TEST
By
KHAISA JERRY

2. Objectives
 To detect possible renal damage
 Assessment of its severity.
 To observe the progress of renal
disease
 To monitor the safe and effective
use of drugs which are excreted
in the urine

3. Causes of kidney functional disorders
• Pre-renal e.g.
decreased
intravascular
volume
• Renal e.g. acute
tubular necrosis
• Postrenal e.g.
ureteral
obstruction

4. TEST of Renal Function Test
• Urine examination
• Tests of excretory functions
• Creatinine clearance test
• Estimation of BUN and serum creatinine
levels

5. Urine Examination
Chemical
Physical
• Apprearan
ce
• Volume
• Specific
gravity
• Odor
•
•
•
•
Glucose
Ketones
Bilirubin
urobilinoge
n
• Protein
• pH
Microscopic
• Cells
• Casts
• Crystals

6. ESTIMATION OF BLOOD UREA NITROGEN
(BUN) & SERUM CREATININE
 Blood Urea Nitrogen
 urea nitrogen is a form break down of
proteins
 Normal values of BUN and creatinine are as
follows;
BUN = 8-25 mg/dl
Creatinine = 0.6-1.6 mg/dl

7. ESTIMATION OF BLOOD UREA NITROGEN
(BUN) & SERUM CREATININE
The estimation is most useful for the assessment of the
severity and progress of renal failure in;
1. Acute tubular necrosis
2. Acute glomerulonephritis
3. Chronic renal disease
4. Post-renal obstruction
Decrease in BUN level may be caused by;
1. Low protein diet
2. Liver damage
3. Dialysis

8. Laboratory test
(Glomerular filtration rate)
 Creatinine Clearance test
- measures the rate at which the kidneys
are able to remove (to clear) a filterable
substance from the blood.
- creatinine clearance is a rough measure of
the glomerular filtration rate
a) Serum creatinine conc (Crs)
b) Urine creatine conc ( Cru)
c) Urine Volume

9. Laboratory test
(Glomerular filtration rate)
Creatinine clearance=(Cru x V/t) / Crs
• Normal range male
•
female
= 85 – 125 ml/min
= 75 – 115 ml/min

10. Laboratory test
(Glomerular filtration rate)
 Try to calculate this=)
Using urine creatinine of 120mg/dl, serum
creatinine of 1.0 mg/dl and urine volume of 1440
ml obtained from 24 –hour specimen. Calculate
the GFR
Answer ?

11. Laboratory test
(Glomerular filtration rate)
Formula;
Creatinine clearance
= (Cru x V/t) / Crs
= [120mg/dl x 1440ml / (24H x 60min)]
1.0mg/dl
=120 x 1440ml / 1440min
1.0
=120ml/min

12. TESTS OF EXCRETORY FUNCTIONS
If the clinical findings or simple urine
examination indicate that renal damage is
present, renal function can be assessed by tests
of excretory function.
Following tests can be performed for this
purpose;
• Urine concentration test
• Vasopressin test
• Urine dilution or water load test
• Dye excretion tests