5. ๏ RATE OF URINARY EXCRETION OF
ANY SOLUTE
= RATE OF GLOMERULAR FILTRATION
+ RATE OF SECRETION
- RATE OF REABSORPTION
6.
7. PHYSICAL TESTS
i. URINE VOLUME
๏ Assessment of fluid balance and kidney
function.
Normal value;
adult : 800-2500 mL/day
children : 500-1400 mL/day
8. CLINICAL IMPLICATIONS
๏ 1. polyuria with elevated BUN and creatinine .
diabetic ketoacidosis
partial obstruction of urinary tract
tubular necrosis
๏ 2.polyuria with normal BUN and creatinine.
diabetes mellitus and diabetes
insipidus
tumours of brain and spinal cord
9. ๏ 3.oliguria
Renal causes
renal ischemia
renal disease due to toxic agents
Dehydration caused by prolonged
vomiting,diarrhoea,burns
Obstruction of some area of the urinary tract
Cardiac insufficiency
๏ 4.anuria
Complete urinary tract obstruction
Acute cortical necrosis
Glomerulonephritis
Acute tubular necrosis
11. 2.URINE COLOUR
๏ Yellow colour due to urochrome.
๏ Normal;
Pale yellow to amber
Straw colour- low SG
Amber colour-high SG
12. CLINICAL IMPLICATIONS
๏ Almost colourless urine;
large fluid intake
chronic interstitial nephritis
untreated diabetes mellitus
diabetes insipidus
alcohol and caffeine ingestion
diuretic therapy
nervousness
๏ Orange colour;
fever
carrots or vitamin A
phenazopyridine, nitrofurantoin
13. ๏ Green urine;
pseudomonal infection
chlorophyll
๏ Red urine
RBCs
haemoglobin
myoglobin
porphyrins
๏ Black urine
melanin
phenol poisoning
๏ Smoky urine - RBCs
๏ Milky urine - fat,cystinuria,WBCs
14. INTERFERING FACTORS
๏ Colour darkens on standing
๏ Drugs alter the colour
green - indomethacin
brown - chloroquine,furazolidone
pink to brown - laxatives
red-pink - daunorubicin
orange - rifampicin
blue urine - triamterene
black urine - chloroquine
metronidazole
15. 3.URINE ODOUR
๏ Faint odour owing to the presence of
volatile oils.
normal; aromatic odour.
16. CLINICAL IMPLICATIONS
๏ Diabetes mellitus patients urine have a
fruity odour.
๏ UTIs result in foul-smelling urine .
๏ Infants with a inherited disorder of amino
acid metabolism urine smells like burnt
sugar.
๏ Cystinuria result in sulfurous odour.
17. 4.URINE SPECIFIC GRAVITY
(SG)
๏ Measurement of the kidneys ability to
concentrate urine.
๏ Compares the density of urine against
the density of distilled water.
๏ Normal;
1.005-1.030
23. CHEMICAL EXAMINATION OF
URINE
๏ ENDOGENOUS MARKERS
a) SERUM CREATININE (kreas)
breakdown product of muscle creatine phosphate.
excreted by glomerular filtration and tubular
secretion.
doubles with each 50% decrease in GFR.
if SCr is 1mg/dl, 100% renal function
2mg/dl, 50% renal function
24. ๏ Normal;
URINE CREATININE
men : 14-26mg/kg/24 hours
women: 11-20mg/kg/24 hours
SERUM CREATININE
men : 0.6-1.2 mg/dL
women : o.4-1.0 mg/dL
28. URINE CREATININE
INCREASED BY DECREASED BY
Ascorbic acid Anabolic steroids
Corticosteroids Captopril
Methotrexate Thiazides
Methyldopa Ketoprofen
Cefoxitin
29. CREATININE CLEARANCE
๏ Rate at which creatinine is removed from
the blood.
๏ Useful measure of
glomerular filtration rate
excreting capacity of the kidney.
31. SCHWARTZ FORMULA
crcl(ml/min) = k x ht in cm/scr(mg/dl)
k = 0.45 ,infants < 1 year of age
k = 0.55 ,children and adolescent
females.
k = 0.7, adolescent males.
33. CLINICAL IMPLICATIONS
INCREASED
State of high cardiac output
pregnancy
burns
carbon monoxide poisoning
DECREASED
Impaired kidney function
dehydration
hemorrhage
congestive heart failure
34. INTERFERING FACTORS
๏ Exercise may increase creatinine
clearance and urine creatinine.
๏ Pregnancy increases CrCl
๏ Proteinuria and advanced renal failure
make CrCl an unreliable method for
determining GFR.
35. BLOOD UREA NITROGEN
๏ End product of protein metabolism (liver)
๏ It travels through the blood and is
excreted by the kidney.
๏ BUN measures the amount of nitrogen in
the blood in the form of urea.
36. ๏ Normal value;
Adults : 6-20 mg/dl
Elderly patients : 8-23 mg/dl
Children : 5-18 mg/dl
AZOTEMIA; excessive retention of nitrogenous
waste products.
Renal azotemia ; renal disease (glomerulonephritis
and chronic pyelonephritis).
Prerenal azotemia; severe dehydration
hemorrhagic shock
excessive protein intake.
Postrenal azotemia; urethral stones
tumours
prostatic obstructions.
37. CLINICAL IMPLICATIONS
๏ 1.Increased BUN levels (azotemia)
a.impaired renal function
congestive heart failure
salt and water depletion
stress
acute MI
b. chronic renal diseases
c. Urinary tract obstruction
d. hemorrhage into GI tract.
e. diabetes mellitus
๏ 2. Decreased BUN levels
a. liver failure
b. acromegaly
c. malnutrition
39. ๏ ACE inhibitors
๏ Indomethacin
๏ Penicillin
๏ Thiazides
๏ Rifampin
๏ Spironolactone
๏ Timolol
๏ Cefotaxime
๏ Phenothiazines
๏ Chloramphenicol
๏ Levodopa
๏ Amikacin
โข BUN increased by ๏ BUN decreased by
40. GLOMERULAR FILTRATION RATE
๏ GFR is the volume of water filtered or
cleared out of the plasma per minute.
๏ GFR is approximated by measuring
the urinary excretion rate of a marker
substance.
๏ Example for marker inulin.
42. URINE PROTEINS
๏ Increased amounts of protein is an
important indicator of renal diseases.
๏ Normal value;
Adult male:10-140 mg/dl
Female:30-100 mg/dl
55. URINE CHLORIDE
๏ Diagnose dehydration or as a guide in
adjusting fluid and electrolyte balance.
๏ Also useful in monitoring the effects of
reduced salt diets( CVD,HTN)
๏ Normal value;
adult: 140-250 mEq/24 hours
child : 64-176 mEq/24 hours
57. URINE CHLORIDE
๏ Ammonium chloride
administration
๏ Excessive infusion of
normal saline
๏ Ingestion of sulfides,
cyanides, halogens,
bromides and sulfhydril
compounds.
๏ Carbenicillin therapy
๏ Reduced dietary
intake of chloride
๏ Ingestion of large
amounts of licorice
๏ Alkali ingestion
๏ Dehydration
๏ INCREASED
CHLORIDE
๏ DECREASED
CHLORIDE
58. URINE KETONES
๏ From fatty acid and fat.
๏ Consists mainly of three substances
: acetone,
ฮฒ-hydroxybutyric acid
acetoacetic acid.
normal value;
urine: negative (<0.3 mg/dl)
59. CLINICAL IMPLICATIONS
๏ Hyperthyroidism
๏ Fever
๏ Pregnancy or
lactation
๏ Diabetes mellitus
๏ Starvation
๏ Anorexia
๏ INCREASED
METABOLIC STATES
๏ DECREASED
METABOLIC STATES
60. KETONES IN URINE
๏ Amino salicylic acid
๏ Cefixime
๏ Valproic acid
๏ Dimercaprol
๏ Captopril
๏ Aspirin
๏ Phenazopyridine
๏ INCREASED BY ๏ DECREASED BY
61. MACROSCOPIC EXAMINATION
of centrifuged urine.
๏ 1) Hematuria
it indicates trauma, tumour, systemic
bleeding.
๏ 2) casts
Casts are cylindrical elements with
parallel sides
67. EXOGENOUS MARKERS
๏ INULIN CLEARANCE
normal value;
men : 127ml/min/mยฒ
women: 118ml/min/mยฒ
๏ Fructose polysaccharide.
๏ Patient receives inulin to achieve a steady
blood concentration.
๏ The quantity in plasma and the amount
excreted in urine is measured.
68. IOTHALAMATE
๏ Normal value;
men : 127 ml/min/mยฒ
women: 118 ml/min/mยฒ
๏ Injection of the radioactive exogenous
marker .
๏ These are not widely used.
69. REFERENCES
๏ A manual of laboratory and diagnostic
tests; by Frances Fischbach, Marshall
B.Dunning, Edition 8.
๏ Textbook of therapeutics; Drug and
disease management by
Eric.T.Herfindal,sixth edition.
๏ Comprehensive pharmacy review by
Leon shargel,fourth edition.
๏ Basic skills in interpreting laboratory
data by Mary Lee,fourth edition.
๏ Principles of anaatomy and physiology
by Tortora, tenth edition.