Physical examination of urine along with detailed formation, composition and methods of sample collection and preservation

1. Physical
Examination Of
Urine
By:
Dr. Amita Yadav
MBBS,
MD(Pathology)

2. Urine-
Is an ultrafiltrate of plasma
from which glucose, amino acids, water
and other substances essential to body
metabolism have been reabsorbed.

3. Formation of urine---
 In the normal adults approx. 1200 ml of blood
perfuses the kidney each minute .
 That is 25% of the cardiac output .
 The glomeruli receive blood through afferent
arterioles and an ultrafiltrate of the plasma passes
into the bowman’s space.
 From there the filtrate is passed through the
tubules and the collecting ducts.
 Reabsorption and secretion of various substances .
 Concentration of urine occurs .
 180 lt of glomerular filtrate in 24 hrs is reduced to
1-2 lt .

5. Urine consists of ---
(96%)
water
Inorganic:
Cl-, Na, K.
trace amounts of:
sulfate, HCO3 etc.)
(4%)
dissolved solids:
(2%)
Urea: (half)
(2%)
Other compounds
Organic:
creatinine
uric acid

6. Importance of urine analysis--
-
 1. General evaluation of health
 2. Diagnosis of disease or disorders of the kidneys or
urinary tract
 3. Diagnosis of other systemic disease that affect kidney
function.
 4. Monitoring of patients with diabetes
 5. Screening for drug abuse both as a part of rehabilitation
and in the world of professional sports.
 6. To determine pregnancy in women.

7. Examination Of Urine---
Three steps :
First: physical characteristics of urine are
noted and recorded.
Second: series of chemical tests is run.
Third: urine sediment is examined under
microscope to identify the components of
sediments.

8. Sample Collection---
 random specimen
◦ most commonly received specimen
 First morning urine
◦ the ideal screening specimen
◦ used for routine screening, pregnancy tests and for
determining orthostatic proteinuria
 Fasting Specimen (Second Morning Specimen)
◦ second voided urine specimen used for glucose monitoring
 24-hour specimen
◦ timed specimen is used to determine concentration of a
particular substance
◦ Instruction:
 Day 1 – 7am
 patient voids and discards specimen
 patient collects all urine for the next 24 hours
 Day 2 – 7am
 patient voids and adds this urine to the previously collected urine

9.  Catheterized Specimen
◦ used for bacterial culture
 Midstream Clean-Catch Specimen
◦ an ideal specimen for routine screening and for bacterial culture
◦ patient is instructed to cleanse thoroughly the genitalia and is
asked to collect the midstream portion of urine. When collecting,
patient should be instructed to separate the labia in females or
retract the foreskin in uncircumcised males.
 Suprapubic Aspiration
◦ used for bacterial culture and cytology
sterile needle is introduced into the bladder to collect sample
that is free of contaminants
 Pediatric Specimen
◦ soft, clear plastic bag with adhesive is attached to the genital
portion

10. Suprapubic aspiration-

11. Truly representative sample:
• it is necessary to regulate:
time of collection, length of collection
period, patient's dietary, medical intake
and method of collection.
• Initial morning sample is preferred
(particularly for protein analysis) because
they are more concentrated from
overnight retention in bladder.

12. Preservatives used--
 1. Hydrochloric acid
 2. Toluene
 3. Boric acid
 4. Thymol
 5. Formalin

13. Properly labeled specimen---
 Patient’s full name
 Age and sex
 Date of collection
 Time of collection

14. Specimen Evaluation---
 Before proceeding with any examination
urine sample must be evaluated in terms
of acceptability.
 It includes-proper labeling
-proper specimen for requested
examination.
-proper preservative
-visible signs of contamination
-transportation delay.

15. • Time of analysis:
- must analyzed within 1hour at room
temperature or within 8hours at 2oC- 8oC.
- If not assayed within these time limits,
several changes will occur.

16. Direct visual observation.
• Normal fresh urine:
• Colour: pale or amber
• Appearance- clear.
• Volume :750 - 2000 ml/24hr.

17. • Physical examination involves:
1.Colour
2.Transparency
3.Odor
4.Volume
5.pH
6.Specific gravity

18. 1. Colour -
 Normal urine is clear , pale or straw colour due to
urochrome pigment.
Increases during - Fever
-Thyrotoxicosis
- Starvation
( Small amounts of urobilins and uroerythrin.)
 Factors affecting colour of urine are-
-Fluid balance
-Diet
-Medicines and
-Diseases

19. ABNORMAL COLOURS :
a. COLOURLESS – after ingestion of large
amount of water, polyuria.
b. DEEP AMBER – after exercise, high grade
fever.
c. DEEP YELLOW- Jaundice

20. d. ORANGE BROWN- excreted urobilinogen is
colourless, but it is converted in presence of light
and low pH to urobilin .
e. RED/PINK – in heamoglobinuria , haematuria
, myoglobinuria and porphyria.
f. DARK BROWN/ BLACK- in alkaptonuria .
g. GREEN- phenol poisoning
h. MILKY- presence of chyle , fat.

21.  Silver or milky appearance -----
Pus, bacteria or epithelial cells
 Yellow foam ---- Bilirubin
 Orange, green, blue or red ---- Medications
 Vitamin B supplements can turn urine bright
yellow.
 Cola coloured urine---- Rhabdomyolysis

22. Hematuria-

23. In jaundice-

24. Pyuria-

25. Chyluria-

26. 2- Transparency:
• Urine is normally clear.
• Bacteria, blood, sperm, crystals, or mucus can make urine
look cloudy.
• Turbidity may be due to precipitation of crystals or non
pathologic salts.
• Amorphous phosphate ,ammonium urate and carbonate
precipitate in alkaline urine.
• Uric acid and urates cause white,pink or orange cloud in
acidic urine.

27. • In pathological urine: it is due to pus, blood and
bacteria.
• Degree of cloudiness depends on: pH and dissolved
solids
 Turbidity: may be due to gross bacteriuria,
 Smoky appearance: is seen in hematuria.
 Thread-like cloudiness: is seen in sample full of mucus.

28. 3. Odor ---
 Normally urine -mild aromatic due to
presence of urinoids.It may change to :
a. FRUITY- Ketoacidosis , starvation
b. MUSTY - Phenylketonuria
c. FISHY – UTI with Proteus
d. AMMONICAL - UTI with Escherichia
coli
e. FOUL- UTI
f. SULFUROUS - Cystinuria

29. 4- Volume:
• Is important part of assessment for fluid
balance and kidney functions.
• Adults produce from 750ml-2500ml / 24h,
with the average of about 1.5L per person.
• For routine urine examination, a 10ml-
12ml of sample is optimal for analysis.

30. I . POLYURIA : Urinary volume > 2500mL
per day
 CAUSES :
-Excessive intake of water ( polydipsia ).
- Diabetes mellitus and diabetes insipidus.
- Drugs with diuretic effect such as caffeine ,
alcohol and diuretics.
-.chronic renal failure

31. Oligourea-
urinary volume < 500 ml/day
Causes-
 A. PRERENAL : loss of intravascular
volume
- haemorrhage
- dehydration
- severe vomiting
-severe burns

32. B. POSTRENAL :
-bilateral hydronephrosis
-long standing obstruction of urinary tract.
Obstruction may be due to clots , stones ,
strictures , tumour, sloughed tissues.
C .RENAL PARENCHYMAL DISEASES

33. III . COMPLETE SUPRESSION : Of urine
is called anuria ( < 150mL /day)
CAUSES :
-Retention of urine as in BPH and stricture
in urethra.
-Stone and tumours in kidney.

34. 5. pH -
Normal reaction of urine is acidic with pH
4.6 to 7.6.
CAUSES OF HIGHLY ACIDIC URINE :
a. Protein-rich diet.
b. UTI by E.coli
c. Respiratory and metabolic acidosis
d. Ingestion of acidic food.

35. CAUSES OF ALKALINE URINE:
a. If specimen is allowed to stand at room
temperature , it becomes alkaline.
b. For the treatment of uric acid calculi
c. UTI by urea splitting bacteria – proteus,
pseudomonas

36. Methods of pH estimation-
--
1.LITMUS PAPER TEST :
2. pH INDICATOR PAPER :
3. PH METER :
4. REAGENTS STRIP TEST:

37. Litmus paper test---

38. 6. Specific Gravity -
- It depends on amount of solutes in solution.
-It reflects the relative degree of concentration
or dilution of a urine specimen.
- It helps in evaluating the concentrating and
diluting abilities of the kidneys
- Urea( 20 %) ,Na Cl (25%), Sulphate ,
Phosphate – major contributors
- SG ranges from 1.003-1.035.
- Specific gravity of urine in normal adults
with adequate fluid intake is 1.016 – 1.022.

39.  Increase in specific gravity-
Diabetes mellitus
Nephrotic syndrome
Fever
Congestive heart failure
 Decrease in specific gravity-
Diabetes insipidus
Compulsive water drinking
• Isosthenuria -Specific gravity is fixed (1.010 )

40. Measurement of specific
gravity-
1. Urinometer method-
Based on principle of buoyancy
2. Refractometer method-
Measures refractive index of
dissolved
solids
3. Reagent strip method-
indirect method .
3 main ingredients : polyelectrolyte ,
indicator and a buffer.

41. Urinometer-

42.  Urinometer is a hydrometer that is
calibrated to measure the specific gravity
of urine at a specific temperature, usually
at 200C.
 Based on principle of buoyancy so the
urinometer will float higher in urine than
in water, because urine is denser.
 Thus higher the specific gravity of a
specimen, the higher the urinometer will
float.

43.  Specific gravity is affected by presence
of dense molecules, protein and glucose.
 Subtract 0.003 from specific gravity after
temperature correction for each 1 g/dl of
protein and 0.004 for each 1g/dl of
glucose.
 Temperature correction-
 For every 30C below 200C, subtract
0.001 from the reading and for every 30C
above 200C, add 0.001.