·        Lecture 39& 40 : Urine analysis-1Collection of urine samples     طFactors affecting specimen, types of urine samples     طQuality control, sample  analysis and reporting results     ط                                           B3  367-  70 ;  C4    165-   173

Urine Collection & Type:A. Random (first void): for protein, glucose, specific gravity, osomlility,

Dark-colored contained for some test (e.g. bilirubin)B. Timed (12-24hrs/befor or after a meal):

Low electrolyte, catecholamine in morning then peak at noonPreservatives (acid/base/refrigeration) used in certain analytes and bact. growth

Factors affecting specimenTiming:

Best time is early morning (basal state)Diet:

physicians must not if diet restriction is require to phlebotomistFasting Specimen: diet high in protein, glucose, saturated &

unsaturated FA, caffeine, serotoninsExercise:

Moderate exercise can affect certain valuesStress:

Emotions may falsely elevate white blood cellsPasture:

Body diurnal rythms and pasture (sitting or laying)

TestsTest to assess nephron function (renal): glomeral filtration, tubular secretion

& reabsorptionUrea & Creatinine (waste products) to determine clearance rate24hr collection

Creatinine (non protein nitrogen):gives clearance of glomeral filtration by colorimetric assayValues calculated relating to serum creatinine

Urea:Filtered by glomerlus & 40% reabsorbed by tubules (no good for

clearance)Test is time-consuming, expensive & difficult (been discontinued)

Analytical methodsElectrophoresis:

Distiguish glomeral nephopathy & tubular proteinuria & abnormal globulins

Urinalysis:Assess renal status & indicates glucose & hepatic-biliary functionPhysical & Chemical Exam

Specific Gravity:Most common is refractometer (urine/water)Indirect colorimeteric reagent strip

·        Lecture41& 42 : Urine analysis-2Physiochemical characters     طPhysical examination     طChemical examination     ط

Physical Character & ExamCollection:

morning specimen preferred (mid stream), analysis within 1hr particularly for proteinsChange as false positive nitrite, ^organism, ^ ammonia, ^ pH, ^casts

Appearance:Yellow (urochrome, urobilin), yellowish-brown to green (bile), Red &

Brown (porphyrins)Redish-Brown (Hb, RBC), Brownish-Black (alkaptunria)Drugs & food also alters colour

Physical Character & ExamOdor:

Pungent (fresh), ammonia (urea), noxious/fecal (infection), fruity (diabetes)

Turbidity (depends on pH & solids):Turbid (bact.), smoky (hematuria), thread-like cloudness (mucous)Alkaline: precipitate phosphate & carbonate (turbid)Acidic: precipitate ureate (cloudy)

Volume:Balance between ingestion & loss (lung, sweat, intestine)Polyuria: in diabetes & chrinic renal diseas, acromegaly, edomaAnuria/oliguria: (<200ml/day)

Physical Character & ExamSpecific Gravity:Weight of 1ml urine (g) divided by weight of 1ml of water (g)Indication density & solid dissolvedAssess hydration/dehydration statusIndicates concentration ability of the kidneyDiseases:Normal 1.005-1.030Diluted (1.000-1010) diabetes insipidusConcentrated (1.025-1.030) diabetes milletus, dehydration liver

disease, congestive heart failure, adrenal insufficiency, nephorsisFixed (1.010) isosthenuria in anuria due to tubular damage

Physical Character & ExampH:normally 4.5-8.0acidic <7.0 caused by phosphate (as salt congegate, Na+, K+..)reflects excretion of metab.. acids (pyruvate, lactate, citrate)systemic acidosis: dibetes milletus, renal tubular acidosisAlakine >7.0React to gastric HClInfection & bacterial contamination, medication (K citrate), fanconi's

syndrome

Chemical Exam:Reagent strip: plastic coated with different reagents bands for analytesAutomated /semi-automated (reflectance photometrySpecific Gravity if above abnormal

Chemical Exam:AnalytesGlucose/Ketones: normaly absent (carbohydrates)Proteins: qualitative proteinuria (alb)Nitrite: nitrate to nitrite (bact.)Leukocyte Estrase: WBCBilirubib/Urobilinogen: HB to Bil to Uro in gut by bact. To feces (in urine jaundice)HB/Blood: intact in renal trauma, infection, obstruction, neoplasms

·        Lecture 43& 44 : Urine analysis-3Microscopic examination, urinary stones      ط ,Reporting urine analysis      ط                                           B3  367-  70 ;  C4    165-   173

Microscopic ExamCentrifuge & microspically examine sedimentCells (counted in high-powered field):1. RBCs:^0-2/hpf hematoma (sever exercise, menstrual)Trauma, vessel injury, calculi obstruction, pyelohephrytis, cistisis, infection2. WBCs:^0-1/hpf phagocytes (neutrophils)Glumeralonephritis, urinary tract infection, inflammationLarge cell (glitter cells) no pathological significance3. Epithelia Cells:Normally lining nephrone & urinary tractLarge, flat, squamous vaginal epithelial cellsRound, uninucleated ^ 2/hpf tubular injury or degeneration, inflammation,

neoplasm

Microscopic ExamCentrifuge & microspically examine

sediment

Miscellanous:Spermatozoa, yeast, parasites

Bacteria:Normaly urine is sterileSkin or air contamination^20/hpf need culture (pregnancy,

diabetes)

Microscopic ExamCentrifuge & microspically examine sediment

Casts:Precipitate of nephrons (mucoprotein from tubular epithelial)From during renal stasis, ^salts, ^protein concentration, low pH1. Hyaline (gel cytoplasm): glomerular leak of protein (fever, dehydration,

stress)2. Grnular: epithelial cell inclusions (not pathogenic), but some in lead

toxicity3. Cellular:-Erythrocytic casts: glomerular inflammation-Luekocytic casts: inflammation of nephrons-Epithelial casts: normal-Waxy casts: tubular inflammation-Fatty casts: renal failure-Broad casts: renal failure

Microscopic ExamCentrifuge & microspically examine sediment

Crystals:In Acid Environment (normal):

Calcium oxalate, colourless envelop (star-like appearance) - normalUrate, yellow-red mass (grain appearance)- normalUric Acid, yellow to red-brown (rosette, prism shape)- normalCholesterol, clear (flat, rectangular plates) – nephritic syndromeCystine, colorless (flat hexogen) - pathological

In Alkaline Environment:Amorphous Phosphate, colorless (fine mass, sand-like) - normalCalcium carbonate, colorless (dumbbell, sphere) – normalTriple phosphate, colorless (prism, coffin lid-like) – normalAmmonium biurate, yellow-brown (spiny, sphere, thorn-like) – normalTyrosin/Leucine, yellow (smooth needles, sphere) – liver disease

Calculi (stone):Stones formed by the combination of various crystallized substance Table24.2Most common is calcium oxalateRecurrence mainly because of reduced urine flow rate & saturationChemical analysis of stone is important to determine causeStones cause obstruction leading to hematuria, infection, pain