Urinalysis. macroscopic analysis. biochemical examination. microscopic assessment. quantity color odour clarity

Transcription

1 Urinalysis

2 Urinalysis an array of tests performed on urine one of the most common methods of medical diagnosis easy to perform, non-invasive fresh urine (midstream urine collection, ml) or 24 h urine

3 Reasons to perform Routine medical evaluation: general yearly screening, assessment before surgery (pre-operative assessment), admission to hospital, screening for kidney disease, chronic diseases: diabetes mellitus, hypertension (high blood pressure), liver disease Assessing particular symptoms: abdominal pain, jaundice, thirst, weight loss painful urination, flank pain, fever, blood in the urine Diagnosing medical conditions: urinary tract infection, kidney infection, kidney stones, kidney impairment, kidney inflammation (glomerulonephritis) Monitoring disease progression and response to therapy: diabetes related kidney disease, blood pressure related kidney disease

4 Urinalysis macroscopic analysis quantity color odour clarity biochemical examination specific gravity / density ph blood, protein glucose, ketones, bilirubin, urobilinogen microscopic assessment

5 Macroscopic analysis Quantity ml daily normal water intake under 500 ml daily: oliguria under 100 ml daily: anuria above 2500 ml daily: polyuria

6 Macroscopic analysis Color transparent solution can range from colorless to amber, a pale yellow physiological: the color comes primarily from the presence of urobilin ( heme hemoglobin aging red blood cells)

7 Macroscopic analysis Abnormal color: dark yellow dehydration light orange B vitamins orange drugs (rifampicin, phenazopyridine) dark orange to brown jaundice,liver diseases black or dark-colored (melanuria) melanoma reddish or brown porphyria, hematuria pink or reddish consumption of beets greenish consumption of asparagus fluorescent yellow / greenish dietary supplemental vitamins (B vitamins)

8 Macroscopic analysis Odor described as urinoid can be strong in concentrated specimens, does not imply infection fruity or sweet odor diabetic ketoacidosis ammoniacal odor alkaline fermentation pungent odor UTIs other abnormal odors : medications and diet, gastrointestinal diseases

9 Macroscopic analysis Turbidity / Clarity bacterial infection proteinuria crystallization of salts: phosphates clears if 10% acetic acid is added urates clears by heating oxalates clears if HCl is added

10 Biochemical properties aqueous solution: > 95% water urea 9.3 g/l chloride 1.87 g/l sodium 1.17 g/l potassium g/l creatinine g/l other dissolved ions, inorganic and organic compounds some diseases alter the quantity and consistency of the urine e.g. glucose diabetes

11 Biochemical properties Density / specific gravity normal urine specific gravity: high values: the kidney is actively reabsorbing water fluid depletion or renal failure due to reduced renal perfusion abnormal urinary compounds e.g. glucose in diabetes low values: failure of the renal tubules to concentrate urine usually associated with high urine volumes

12 Biochemical properties Acidity(pH) normally acid (ph = 5-6) ph can vary between ph can be modified by drugs, diseases (diabetes, renal tubular acidosis), urinary infections ph : drugs (acetazolamide, potassium citrate, and sodium bicarbonate), diet high in citrus, vegetables ph : drugs (ammonium chloride, chlorothiazide diuretics, methenamine mandelate), diet high in meat or cranberries modified ph can lead to stone formation

13 Biochemical properties Demonstration of proteins macromolecules they are not normally present in measurable amounts in the glomerular filtrate or in the urine proteinuria the permeability of the glomerulus is abnormally increased the function of the proximal convolute tube is altered pathological if > 30mg/24 h

14 Biochemical properties Esbach's test put 5 ml of urine in a test tube add 1 ml of Esbach's reagent (10g picric acid and 20 g citric acid dissolved in 1 l of water) appearance of a white-yellow precipitate indicates the presence of proteins

15 Biochemical properties reaction with trichloroacetic acid put 5 ml of urine in a test tube add 1 ml of trichloroacetic acid (10% or 20%) appearance of a flocculent precipitate indicates the presence of proteins

16 Biochemical properties Qualitative determination of urobilinogen Ehrlich's test put 5 ml of fresh urine in a test tube add 3-4 drops of Ehrlich reagent (pdimethylaminobenzaldehyde in HCl) after 1-2 min pink or faint red color that intensifies on heating indicates increased urobilinogen levels

17 Biochemical properties Qualitative determination of reducing sugars Nylander's test a test for glucose in the urine using a solution containing bismuth subnitrate which forms a black precipitate in a positive reaction put 5 ml of urine in a test tube add 1 ml of Nylander's reagent (potassium sodium tartrate, sodium hydroxide, and bismuth subnitrate in water) and heat for 4 min in the presense of a reducing sugar the bismuth is reduced and forms a black precipitate

18 Microscopic assessment the urine sediment is centrifuged and examined using low power microscope (at least 10 microscope fields) cells: epithelial cells red blood cells white bloods cells crystals casts bacteria or yeast in counting chambers using urine produced over a determined time (ex. 180 minutes)

19 Microscopic assessment red blood cells 1-5 RBC/HPF (400x) or 1000 RBC/min renal origin: deformed, faded color from the urinary tract: normal shape and color inflammation, injury, or disease in the kidneys or elsewhere in the urinary tract

20 Microscopic assessment white blood cells: 3-5 WBC/HPF or 2000 WBC/min usually in groups of cells if they form casts: renal origin increase infection or inflammation in the urinary tract

21 Microscopic assessment epithelial cells from the bladder: transitional epithelial cells from the external urethra: squamous epithelial cells increase urinary tract infections, inflammation, malignancies

22 Microscopic assessment Urinary casts: cylindrical structures produced by the kidney formed in the distal convoluted tubule and collecting ducts of nephrons types: hyalin red cell granular epithelial waxy fatty

23 Microscopic assessment hyaline casts: the most frequently occurring colorless, homogeneous, transparent, usually rounded ends

24 Microscopic assessment red cell casts: renal hematuria brown to almost colorless usually diagnostic of glomerular disease

25 Microscopic assessment white cell casts: indicative of inflammation or infection of the kidneys

26 Microscopic assessment granular casts: indicate significant renal disease color: black to pale yellow

27 Microscopic assessment epithelial casts: rare; in renal diseases that primarily affects the tubules

28 Microscopic assessment waxy casts: result from the degeneration of granular casts severe chronic renal failure, malignant hypertension, and diabetic disease of the kidney short, broad casts, with blunt or broken ends

29 Microscopic assessment Crystals solutes can form crystals if: the urine ph is increasingly acidic or basic; the concentration of dissolved substances is increased; and the urine temperature promotes their formation they may group together to form kidney "stones" or calculi