KIDNEY FUNCTION TESTS- ROLE OF KIDNEY, MACROSCOPIC, MICROSCOPIC AND BIOCHEMICAL EXAMINATION

1. KIDNEY
FUNCTION TESTS
SELINA SRAVANTHI
SNVPMV
HYDERABAD
1
ROLE OF KIDNEY & URINE ANALYSIS (PHYSICAL, MACROSCOPIC & MICROSCOPIC CONSTITUENTS)

2. ROLE OF KIDNEY
◘ The kidneysperform many crucial functions, like
◘ maintaining overallfluid balance, regulating and filtering minerals from blood
◘ water and electrolyte balance.
◘ acid base balance.
◘ filteringwaste materials from food, medications, and toxic substances
◘ creating hormones that help produce red blood cells, promote bone health,
◘ Secretion of erythropoietin, activation of vitamin D and activation of
angiotensinogen by renin
◘ regulate blood pressure
◘ Metabolic Function: site for gluconeogenesis
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3. ROLE OF KIDNEY
◘ The functional unit of kidney are Nephrons
◘ maintaining overall fluid balance
◘ Each kidney contains about 1,000,000 to 1,300,000 nephrons.
◘ The nephron is composed of glomerulus and renal tubules.
◘ The nephron performs its homeostatic function by ultra filtration at
glomerulus and secretion and reabsorption at renal tubules.
◘ Urine is formed by the following mechanism
◘ Glomerular Filtration
◘ Tubular Reabsorption
◘ Tubular Secretion
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ROLE OF KIDNEY

5. ROLE OF KIDNEY
◘ Each nephron is a complex apparatus comprised of five basic parts:
◘ Glomerulus: functions to filter incoming blood.
◘ Factors facilitate filtration:
◘ high pressure in the glomerular capillaries, which is a result of their position
between two arterioles.
◘ the semipermeable glomerular basement membrane, which has a
molecular size cutoff value of approximately 66,000 Da.
The volume of blood filtered per minute is the glomerular filtration rate (GFR),
and its determination is essential in evaluating renal function.
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6. ROLE OF KIDNEY
◘ Each nephron is a complex apparatus comprised of five basic parts:
◘ Proximal convoluted tubule:
◘ Returns the bulk of each valuable substance back to the blood circulation.
◘ 75% of the water, sodium, and chloride.
◘ 100% of the glucose (up to the renal threshold)
◘ almost all of the amino acids, vitamins, and proteins and varying amounts of urea,
uric acid, and ions, such as magnesium, calcium and potassium.
◘ Secretes products of kidney tubular cell metabolism, such as hydrogen ions,
and drugs, such as penicillin.
◘ With the exception of water and chloride ions, the process is active; that is, the
tubular epithelial cells use energy to bind and transport the substances across
the plasma membrane to the blood.$elin@ SNVPMV 6

7. ROLE OF KIDNEY
◘ Each nephron is a complex apparatus comprised of five basic parts:
◘ Loop of Henle:
◘ Facilitates the reabsorption of water, sodium, and chloride.
The osmolality in the medulla in this portion of the nephron increases steadily from
the corticomedullary junction inward
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8. ROLE OF KIDNEY
◘ Each nephron is a complex apparatus comprised of five basic parts:
◘ Distal convoluted tubule:
◘ The filtrate entering this section of the nephron is close to its final
composition.
◘ Effects small adjustments to achieve electrolyte and acid-base
homeostasis (under the hormonal control of both antidiuretic hormone
(ADH) and aldosterone).
The distal convoluted tubule is much shorter than the proximal tubule, with two or
three coils that connect to a collecting duct.
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9. ROLE OF KIDNEY
◘ Each nephron is a complex apparatus comprised of five basic parts:
◘ Collecting duct:
◘ The collecting ducts are the final site for either concentrating or diluting
urine.
◘ The hormones ADH and aldosterone act on this segment of the nephron
to control reabsorption of water and sodium.
◘ Chloride and urea are also reabsorbed here.
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10. PURPOSE OF TESTING RENAL FUNCTIONS
◘ Many diseases affect renal function.
◘ In most renal diseases, complete nephron is affected.
◘ In some diseases, selective impairment of renal function is seen
◘ Impairment of glomerular function or,
◘ Impairment of one or more tubular function
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11. ◘ To assess the functional capacity of kidney- diagnose the disease or
disorders of kidneys and urinary tract and other systematic diseases
◘ Early detection of possible renal impairment.
◘ Severity and progression of the impairment.
◘ Monitor response to treatment
◘ Monitor the safe and effective use of drugs which are excreted in the
urine
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PURPOSE OF TESTING RENAL FUNCTIONS

12. ◘ Urine examination is usually employed to diagnose most of the kidney
disorders
◘ Urine examination is classified into 3 types
◘ macroscopic examination
◘ microscopic examination
◘ biochemical examination
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URINE ANALYSIS

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URINE
ANALYSIS
PHYSICAL
EXAMINATION
Volume
Colour
Odour
pH
Specific Gravity
MICROSCOPIC
EXAMINATION
Cells
Crystals
Casts
Microorganism
Parasites
Contamination
BIOCHEMICAL
EXAMINATION
Proteins
Sugars
Ketone Bodies
Bile salts
Bile pigments
Blood

14. ◘ COLOUR
◘ Normal color of urine is pale yellow due to urochrome
◘ Abnormal colours are observed during diseased state.
◘ PINK/ORANGE/ RED – haematuria, beetroot juice intake, Porphyrins,
Rifampicin
◘ RED- BROWN- BLACK – Haemoglobin, Homogentisic acid, L-DOPA, melanin
◘ BLUE- cholera
◘ BLUE-GREEN – Pseudomonas
◘ YELLOW-BROWN – bilirubin/ JAUNDICE
◘ YELLOW - GREEN – biliverdin / JAUNDICE
◘ ORANGE/ YELLOW– excessive sweat, fever, Isoniazid, Vitamins B
◘ CLOUDY – Protein intake, crystallisation, precipitation of salts on standing or in
refrigerator
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URINE ANALYSIS - MACROSCOPIC EXAMINATION

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URINE ANALYSIS - MACROSCOPIC EXAMINATION

16. ◘ ODOUR
◘ Smell of normal urine is slightly pungent.
◘ Aromatic Smell- Volatile Fatty Acids
◘ Ammoniacal Smell – Due To Bacterial Action/ Dehydration/ Kidney or Liver
disorders/ Kidney stones
◘ Foul smell – diet with onions, garlic, fish / sulfonamide, diabetes , arthiritis
medication/ Pregnancy/
◘ Mousy/ musky Odour – Ketonuria
◘ Sweet Odour – Diabetes mellitus
◘ Smell of maple syrup – maple syrup urine disease – body doesn’t metabolize AA
like leucine, isoleucine and valine
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URINE ANALYSIS - MACROSCOPIC EXAMINATION

17. ◘ VOLUME
◘ Normal volume is 1000 – 2000 mL/24 hours (depending on water intake)
◘ Increase in urine levels – POLYURIA (more than 2000 mL/ 24 hrs)
◘ Drugs
◘ IV solutions
◘ Diabetes Mellitus
◘ Diabetes insipidus
◘ Decrease in urine levels – OLIGURIA (Less than 400 mL/ 24 hrs)
◘ Dehydration
◘ Acute glomerulonephritis
◘ Less than 100 mL/ 24 hrs – ANURIA
◘ Congestive heart failure
◘ Renal tract obstruction
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URINE ANALYSIS - MACROSCOPIC EXAMINATION

18. ◘ pH
◘ Normal pH of urine is 6 – 6.5 (around)
◘ High pH – Renal Alkalosis
◘ Due to sodium carbonate containing drugs
◘ Strict vegetarian diet
◘ Low pH – Renal Acidosis
◘ Ammonium chloride containing drugs
◘ Starvation
◘ Ketosis
◘ Fever
◘ Diabetes$elin@ SNVPMV 18
URINE ANALYSIS - MACROSCOPIC EXAMINATION

19. ◘ Specific Gravity
◘ Measured using urinometer or refractometer
◘ Measurement of urine density reflects the ability of
the kidney to concentrate or dilute the urine
relative to the plasm from which it is filtered.
◘ Normal value: 1.001-1.040
◘ Increase in specific gravity
◘ Low water intake/ dehydration
◘ Diabetes mellitus
◘ Albuminuria
◘ Acute nephritis
◘ Decrease in specific gravity
◘ Absence of ADH
◘ Renal tubular damage$elin@ SNVPMV 19
URINE ANALYSIS - MACROSCOPIC EXAMINATION
S.G Osmolality
(mosm/kg)
1.001 100
1.010 300
1.020 800
1.025 1000
1.030 1200
1.040 1400
Isosthenuria
Persistent production of fixed
low Specific gravity urine
isoosmolar with plasma despite
variation in water intake.

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URINE ANALYSIS - BIOCHEMICAL EXAMINATION

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URINE
ANALYSIS
PHYSICAL
EXAMINATION
Volume
Colour
Odour
pH
Specific Gravity
MICROSCOPIC
EXAMINATION
Cells
Crystals
Casts
Microorganism
Parasites
Contamination
BIOCHEMICAL
EXAMINATION
Proteins
Sugars
Ketone Bodies
Bile salts
Bile pigments
Blood

22. ◘ PROTEINS – Qualitative tests
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URINE ANALYSIS – BIOCHEMICAL EXAMINATION
TEST OBSERVATION INFERENCE
Urine +
sulphosalicylic
acid drop by
drop
White
precipitate
Presence of
proteins
Hellers nitric acid
ring test : 3mL
conc nitric acid
+ urine sample
drop wise along
the sides of test
tube
White ring is
formedat the
junctionof two
layers
Presence of
proteins
Heat
coagulation: boil
5mL of urine
sample for 5 min
Turbidityis
observed
Presence of
proteins
◘ Presence of protein in urine – Proteinuria
◘ Severeexercise
◘ High protein diet
◘ Pregnancy
◘ Kidney Disease
◘ Damage to lowerurinary tract
◘ Fasting

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URINE ANALYSIS - BIOCHEMICAL EXAMINATION

24. ◘ SUGARS – Qualitative tests
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URINE ANALYSIS – BIOCHEMICAL EXAMINATION
TEST OBSERVATION INFERENCE
Benedicts reagent test : 2mL
urine + 2mL benedicts
qualitativereagent and boil for
2 min and cool
a) Green ppt
b) Brick red ppt
c) Yellow ppt
a)1% glucose
b)2%glucose
c) More than 2%
glucose
Fehling's reagent test: 2mL of
Fehling's A and Fehling’s B
+2mL urine boil for 2 to 5
minutes
Red or yellow ppt is formed Presence of
Glucose
◘ Presence of glucose in urine – Glucosuria
◘ Diabetes mellitus,
◘ Hypertension
◘ Corticosterol drugs

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URINE ANALYSIS - BIOCHEMICAL EXAMINATION

26. ◘ KETONE BODIES – Qualitative tests
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URINE ANALYSIS – BIOCHEMICAL EXAMINATION
TEST OBSERVATION INFERENCE
Rothera’s test : 5mL urine +
small amt of ammonium
sulphate + 2 drops of sodium
nitroprusside + 2mL of strong
ammonia solution and wait
for 10 min
Permanganate pink
colour is observed
Presence of ketone
bodies
◘ Presence of ketone bodies in urine – Ketonuria
◘ Diabetes mellitus,
◘ Starvation
◘ Excessive fatty acid metabolism
◘ Pregnancy

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URINE ANALYSIS - BIOCHEMICAL EXAMINATION

28. ◘ BILE SALTS – Qualitative tests
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URINE ANALYSIS – BIOCHEMICAL EXAMINATION
TEST OBSERVATION INFERENCE
Sulphur powder test: Take 5
mLurine in a beakerand
sprinkle sublimed sulphur
powder
Powdersinks to bottom Presence of bile salts
◘ Presence of Bile salts in urine may be due to
◘ Jaundice
◘ Obstruction of biliary tract
◘ Liverdiseases

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URINE ANALYSIS - BIOCHEMICAL EXAMINATION

30. ◘ BILE PIGMENTS – Qualitative tests
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URINE ANALYSIS – BIOCHEMICAL EXAMINATION
TEST OBSERVATION INFERENCE
Gmelin test : 10mL of urine + 2
to 3 drops of dil. HCl filterit ,
allow the filter paper to dry
and put a drop of HNO3
Coloration of paper in
followingorder
Green, Blue, Violet, Red,
Yellowishred
Presence of bile
pigments
Heller’s nitric acid test: 3mL of
conc. HNO3 + add urine drop
wise slowly
Fine play of colors is
observed
Presence of bile
pigments
◘ Presence of Bile pigments in urine can be determined by Vandenbergh & Fouchet test

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URINE ANALYSIS - BIOCHEMICAL EXAMINATION

32. ◘ BLOOD – Qualitative tests
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URINE ANALYSIS – BIOCHEMICAL EXAMINATION
TEST OBSERVATION INFERENCE
Benzidine test : 2mL urine +
few mL of H2O2 + pinch of
bezidine in acetic acid
Green colour is
observed
Presence of blood
◘ Presence of blood in urine - Hematuria
◘ Renal Caliculi
◘ Glomerulonephritis
◘ SevereUTI
◘ Renal tract tumor

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URINE ANALYSIS - BIOCHEMICAL EXAMINATION

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URINE
ANALYSIS
PHYSICAL
EXAMINATION
Volume
Colour
Odour
pH
Specific Gravity
MICROSCOPIC
EXAMINATION
Cells
Crystals
Casts
Microorganism
Parasites
Contamination
BIOCHEMICAL
EXAMINATION
Proteins
Sugars
Ketone Bodies
Bile salts
Bile pigments
Blood

35. ◘ Take the urine sample (10-15 mL) into test tube and centrifuge it at low speeds
(2000-3000 rpm) for 5-10 min.
◘ The supernatant fluid is discarded
◘ A small drop of sediment left at the bottom is mixed is taken on a glass slide.
◘ The sample is studied under a microscope for
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URINE ANALYSIS - MICROSCOPIC EXAMINATION
LOW POWER
◘ Cells
◘ Crystals
◘ Casts
HIGH POWER
◘ Cells – WBC/ leucocytes
◘ Crystals
◘ Microorganisms

36. ◘ Presence of Granular Casts, RBC, bacteria, Glucose, Albumin and Ketonebodiesis
abnormal.
◘ Hematuriais the presence of abnormal numbers of red cells in urine due to any of several
possible causes
◘ glomerular damage,
◘ kidney trauma,
◘ urinary tract stones,
◘ acute tubular necrosis,
◘ upper and lowerurinary tract infections,
◘ Nephrotoxins
◘ White blood cell casts are most typical for acute pyelonephritis, but they may also be
present with glomerulonephritis. Their presence indicates inflammationof the kidney.
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URINE ANALYSIS - MICROSCOPIC EXAMINATION

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URINE ANALYSIS - MICROSCOPIC EXAMINATION
◘ CRYSTALS
◘ Tyrosinecrystals with congenital tyrosinosis
◘ Leucine crystals in patients with severe liver disease or with maple syrup urine
disease.
Urinary crystals.
(A) Calcium oxalate crystals;
(B) uric acid crystals
(C) triple phosphate crystals with
amorphous phosphates ;
(D) cystine crystals.

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URINE ANALYSIS - MICROSCOPIC EXAMINATION
◘ CRYSTALS
◘ Crystals found in basic urine are
carbonate and phosphate crystals

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URINE ANALYSIS - MICROSCOPIC EXAMINATION
◘ CELLS
◘ Few epithelial cells and RBC are
observed occasionallyin urine
◘ This may be due to fever or urinary tract
calculi or acute renal damage or
glomerulonephritis

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URINE ANALYSIS - MICROSCOPIC EXAMINATION

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URINE ANALYSIS - MICROSCOPIC EXAMINATION

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URINE ANALYSIS - MICROSCOPIC EXAMINATION
◘ CASTS
◘ Urinary casts are cylindrical structures produced by the kidney and present in
the urine in certain disease states.
◘ They form in the distal convoluted tubule and collecting ducts of nephrons, then
dislodge and pass into the urine, where they can be detected by microscopy.
◘ These casts are of two types
CELLULAR CASTS
◘ RBC
◘ WBC
◘ Epithelial
ACELLULAR CASTS
◘ Hyaline casts
◘ fatty casts
◘ waxy casts
◘ pigment casts

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URINE ANALYSIS - MICROSCOPIC EXAMINATION
◘ CASTS

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URINE ANALYSIS - MICROSCOPIC EXAMINATION
◘ CASTS

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