Urine R/E and RFTs

Urology Department
Lady Reading Hospital
peshawar, pakistan.

1. Urine R/E also known as urine analysis or urinalysis One of the fundamental test in kidneys or urinary tract diseases Diagnosis of other systemic disease that affect kidney functions Monitoring of patients with diabetes Screening for drug abuse ( eg Sulfonamide or aminoglycosides )

2. Containers for collection of urine should be wide mouthed, clean and dry. Analysed within 1 hours of collection else requires refrigeration at 5 degree centigrade.

3. Urinalysis consists of the following measurements: Macroscopic or physical examination Chemical examination Microscopic examination of the sediment Urine culture

4. Examination of physical characteristics: Volume Color Turbidity Odor pH and Specific gravity Osmolality The refractometeror a reagent strip is used to measure specific gravity

5. Normal1-1.5 or 2 L/day Oliguria Urine Output < 400ml/day Seen in Dehydration,Shock Acute glomerulonephritis Renal Failure Polyuria Urine Output > 2.5 L/day, Seen in Increased water ingestion Diabetes mellitus and insipidus Anuria Urine output < 100ml/day Seen in renal shut down

6. Normal pale yellow=due to pigments urochrome , Urobilin and uroerythrin Cloudiness may be caused by excessive cellular material or protein, crystallization or precipitation of non pathological salts upon standing at room temperature or in the refrigerator Colour of urine depending upon it’s constituents.

7. Colorless Very diluted urine over hydration Cloudy Phosphaturia Pyuria chyluria Red Hematuria Myo/hemoglobinuria Anthocynin in beets and blackberries rifampin Orange Dehydration sulfasalazine Yellow Normal Riboflavin Green blue Biliverdin Methyelene blue phenols Brown Uroblinogen Prophyria Fava beens metronidazole Brown black Sorbitol Methyl dopa

8. Freshly voided urine is clear Cloudy urine may be due to phosphaturia, pyuria, Chyluria Lipiduria Hyperoxaluria

9. Normal aromatic due to the volatile fatty acids On long standing Ammonical decomposition of urea forming ammonia which gives a strong ammonical smell) Foul, offensive pus or inflammation Sweet Diabetes Fruity Ketonuria Maple Syrup like Maple Syrup Urine Disease Rancid Tyrosinaemia Characteristic " rotten egg“ odor Cystinuria

10. Reflects ability of kidney to maintain normal hydrogen ion concentration in plasma & ECF Urine pH ranges from 4.5 to 8 Normally it is slightly acidic lying between 5- 6.5. Tested by litmus paper pH paper Dipsticks Acidic Urine Respiratory&metabolic acidosis urine is acidic Respiratory and metabolic alkalosis urine is alkaline Exception RTA type I&II serum acidic and urine alkaline. Type II severe metabolic acidosis urine is acdic Unable to acidify the urine with acidic load diagnostic of RTA

11. PH Help in Dx nd Rx In UTI alkaline urine with PH >7.5 suggest infection with urea splitting organisms(proteus) Urease producing organism convert NH3 into NH4 ion increasing PH causing precipitatios of Ca+MAP crystals PH is acidic in uric acid and cystine stones Alkalinization of urine is important feature of therapy in both cases(uric acid&cystine lithiasis ).

12. It is measure the ratio of urine density compared with water density, which reflects the ability of the kidney to concentrate or dilute the urine relative to the plasma from which it is filtered. Measured By urinometer refractometer dipsticks

13. Normal 1.001-1.035. Increase in Specific Gravity Low fluid intake , Dehydration due to fever,sweating,vomitting and diarrhea Diabetes mellitus( glucosuria ), SIADH. I.v contrast Decrease in Specific Gravity Increased fluid intake Decreasd renal concentrating ability Diabetes insipidus Absence of ADH , Renal Tubular damage. Fixed specific gravity ( isosthenuria )=1.010Specific gravity

14. Amount of material dissolved in the urine. 50-1200 mOsm /L Urine osmolality is the better indicator of Renal function but it can not be measured with dipstick.

15. The chemical analysis of urine us undertaken to evaluate the levels of the following components Blood Protein Glucose Ketones Bilirubin Urobilinogen Wbc’s

16. When the test strip is dipped in urine the reagents are activated and a chemical reaction occurs . Normal urine having fewer than 3RBCs/HPF + ve Dipstick for blood indicates either hematuria , hemoglobinuria , myoglobinuria .

17. Detected by heat coagulation or dipstickMethod Urine proteins come from plasma protein and TommHorsfall (TH ) glycoprotein Healthy individuals excrete 80-150 mg/d of total protein and <30 mg/d of albumin. Normal urine protein is 30% albumin 30% globulin 40% tissue protein Plasma cell dyscrasias (multiple myeloma) can be associated with large amounts of excreted light chains in the urine, which may not be detected by dipstick. The light chains produced from these disorders are filtered by the glomerulus .

18. Cause of proteinuria Glomerular : most common type due to inc permeability of G.M to protein especially albumin e.g in IgA nephropathy and DM Tubular: failure to reabsorb normally filtered proteins of LMW such as Immunoglubulins e.g in fanconi syndrome Overflow proteinuria : absence of underlying disease, due to increase plasma concentration of abnormal immunoglobulins e.g in Multiple myeloma

19. Urine testing for Glucose&Ketones is useful in screening DM. Normally glomerular filteration of Glucose=to tubular reabsorption Renal threeshold corresponds to serum glucose of about 180mg/dl: above this level glucose will be detected in urine. Ketones not found in urine normally, will appear when body COH supplies are depleted & body fats breakdown occur. Occuring in Diabetic Ketoacidosis , pregnancy, after periods of starvations/rapid weight reduction. Acetoacetic acid, b- hydroxy butyric acid,acetone

20. Bilirubin doesn’t appear in urine Uroblinogen in traces amount passes in urine in pathologic condition of hemolysis and hepatocellular diseases. Obstruction of bile ducts or antiboitics that alter intestinal flora will decrease conversion to uroblinogen and their urinary excretion.

21. Less important in urologic practice LN dipstick L.E produced by neutrophils Should be done 5 mints after dipstick is immersed in urine L.E test may be – ve in presence of infection because not all pt with bacteriuria may have significant pyuria It should be done in conjunction with nitrite test for bacteriuria

22. False – ve results Inc specific gravity Glycosuria Presence of uroblinogen Medication that alter urine color Ingestion of large amount of ascorbic acid False + ve results specimen contamination

23. Nitrite test: many species of gram – ve bacteria convert nitrate into nitrite Higher specifity low sensitivity Less accurate in urine specimen having < 5 organism/ml It detects 95% of infected urine specimen and decreases the need for microscopy by as much as 30%

24. Types of cast seen : Acellular cast Hyaline casts, Granular casts, Waxy casts , Fatty casts, Pigment casts, Crystal casts. Cellular cast Red cell casts , White cell casts , Epithelial cell cast The most common type of cast hyaline casts are solidified TammHorsfallmucoprotein secreted from the tubular epithelial cells Red blood cells may stick together and form red blood cell casts. Such casts are indicative of glomerulonephritis , with leakage of RBC's from glomeruli , or severe tubular damage White blood cell casts are most typical for acute pyelonephritis , but they may also be present with glomerulonephritis .

25. First morning urine specimen is the specimen of choice and should be examined within 1 hr. A sample of urine (usually 10 -15 ml) is centrifuged in a test tube at relatively low speed ( about 3,000rpm ) for 5 minutes which produces a concentration of sediment (cellular matter ) at the bottom of the tube. A drop of sediment is poured onto a glass slide , a thin slice of glass (a coverslip ) is place over it and observed under microscope

26. Microscopic analysis with both low power(100 magnification), high power(400 magnif ) Low power: erythrocytes, leukocytes, casts, cystine craystals , oval fat macrophages & parasites like trichomonas vaginalis & schistosoma hematobium High power: circular from dysmorphic erythrocuytes , types of crystals, bacteria & yeasts 1.Cells 2.Casts 3.Crystals 4.Bacteria 5.Yeasts 6.parasites

27. Erythrocytes identified under low power diagnosed (morphology)under high power Circular(non glomerular ) from dysmorphic ( glomerular ) Circular: even distribution of Hb with either a round or crenated contour Dysmorphic : irregulary shaped with minimal Hb and irrigular distribution of cytoplasm

28. Leukocytes: normal 1-2/HPF in men & upto 5/HPF in women in whom urine sample may be contaminated e vaginal secretions. Greater number indicates infection or inflammation in the Urinary tract Old leukocytes: small and wrinkled appearance(vaginal secretions of normal women) Fresh leukocytes: larger and rounder and when the sp.gravity is <1.019 the granules in cytoplasm demonstrates glitterlike movements so called glitter cells.

29. Squamous epi cells: large, central small nucleus about the size of erthrocytes & irregular cytoplasm with granularity. frequently detected in female urine derived from lower portion of urethra, trigone of post pubertal female and vagina Transtional epi cells: smaller than squamous cells having large nucleus & demonstrate promenint cytoplasmic granules near the nucleus reminder of urinary tract Malignant transitional epi cells: altered nuclear size & morphology, can be identified with either routine papanicolaou staining or automated flow cytometry

30. Renal tubular cells: least commonly observed but most significant because their presence always indicates renal pathology. Difficult to distinguish from leukocytes but the are slightly larger

31. Is a protein coagulum that is form in the renal tubules and traps any tubular luminal content within the matrix. Tamm- horsfall mucoprotein is the matrix of all renal casts. Casts have only mucoprotein they are called hyaline casts,(after exercise or heat exposure, pyelonephrits or CKD) Rbc’s cast: entrapped erythrocytes( glomerular bleeding) Wbc’s cast: acute GN, acute PN, acute TIN Fatty cast: nephrotic synd , lipiduria , hypothyriodism

32. Cystine crystals= cystinuria Acidic urine=Ca oxalate, uric acid, cystine Alkaline urine=Ca phosphate, triple( struvite )crystals Cholestrole crystals: lipiduria

33. Each HPF views b/w 1/20,000 – 1/50,000ml Each bacterium seen /HPF = bacteria >30,000/ml 5bacteria/HPF = 100,000/ml Most common candida albicans Biconcave oval shape confused with erythrocytes and Ca-oxalate crystals but yeast can be distinguished by charcteristic budding and hyphea Diabetes and vaginal candidiasis

34. Trichomonas vaginalis : is a frequent cause of vaginitis in women and occasionally of urethritis in men Large cells e rapidly moving flagella that quickly propel the organism across the microscopic field Schistosoma hematobium : extremly common in middle east and north africa Charateristic parasitic ova with a terminal spike

35. Should be examined in pt having prostatis Normal prostatic fluid have few if any leukocytes Presence of large number or clumps of leukocytes is indicative of prostatis Oval fat macrophages are found in postinfection prostativ fluid.

36. Presumptive dx of bacterial infection made by microscopic examination of urinary sediments be confirmed by urine c/s C/s can be used To estimate the numbers of bacteria To identify the exact organism present To predict which drug will be effective to treat the infection C/s are particulary important in Recurrent infections Seriously ill pts Persistent infections Hospitalised pt with UTI Renal insufficency Drug allergies

37. C/s influneced by Method used to collect the urine Patient hydration status Whether patient is taking antimicrobial agent

38. Method Plastic culture plate with blood agar on one side and deoxycholate agar on other side A known amount of urine inoculated on agar on each side & colony counts are determined at 24-48hrs Number of bacteria in 1ml of urine is determined by multiplying the no. of colonies by volume and dilution of the inoculum if any.

39. If antiboitic sensitivity is required Additional culture plate inoculated and small antibiotic impregnated disks placed on the agar. Zones of growth inhibition seen around the disks at 12-24 hrs indicate sensitivity

40. A microscopic examination that show acid fast bacilli can give a presumptive Dx of T.B The rapidity of recovering mycobectrium depend upon pts bacillary load. If smear is highly + ve , culture would become + ve in 1-2 weeks

41. Blood examination Done to measure substance in blood that are normally excreted by kidney. Their level in blood increases in kidney dysfunction. As markers of renal function creatinine , urea,uric acid and electrolytes are done for routine analysis

42. Creatinine : breakdown product of creatine phosphate in skeletal muscle, and is usually produced at a constant rate by the body depending on muscle mass Creatinine is filtered but not reabsorbed in kidney. 0.8-1.2 mg/dl in adults & 0.4-0.8 mg/dl in children. Not increased above normal until 50% of renal function has been lost(GFR<50 ml/min). Methods most widely used for serum creatinine are based on the Jaffe reaction. This reaction occurs between creatinine and the picrate ion formed in alkaline medium (sodium picrate); a red-orange solution develops which is read colorimetrically at 520 nm.

43. • Increased serum creatinine : – Impaired renal function – Very high protein diet – Anabolic steroid users – Vary large muscle mass: body builders, giants, acromegaly patients – Rhabdomyolysis /crush injury – Athletes taking oral creatine . – Drugs: • Probenecid • Cimetidine • Triamterene • Trimethoprim • Amiloride

44. Blood Urea Urea is major nitrogenous end product of protein and amino acid catabolism, produced by liver and distributed throughout intra and extracellular fluid. Urea is filtered freely by the glomeruli . Many renal diseases with various glomerular , tubular, interstitial or vascular damage can cause an increase in plasma urea concentration. The reference interval for serum urea of healthy adults is 10-40 mg/dl. Plasma concentrations also tend to be slightly higher in males than females. High protein diet causes significant increases in plasma urea concentrations and urinary excretion.

45. Measurement of plasma creatinine provides a more accurate assessment than urea because there are many non renal factors that affect urea level. Nonrenal factors can affect the urea level (normal adults is level 10-40mg/dl) like: Mild dehydration, high protein diet, increased protein catabolism, muscle wasting as in starvation, reabsorption of blood proteins after a GIT haemorrhage , treatment with cortisol or its synthetic analogous States associated with elevated levels of urea in blood are referred to as uremia or azotemia . Causes of urea plasma elevations: Prerenal : renal hypoperfusion Renal: acute tubular necrosis Postrenal : obstruction of urinary flow

46. Blood urea is normally doubled when the GFR is halved. Parallel determination of urea and creatinine is performed to differentiate between pre-renal and post-renal azotemia . Pre-renal azotemia leads to increased urea levels, while creatinine values remain within the reference range. In post-renal azotemias both urea and creatinine levels rise, but creatinine in a smaller extent. Enzymatic Berthelot Method is used for blood urea estimation: Principal: Urea + H2O Urease > Ammonia + CO2 Ammonia + Phenolic Chromogen + Hypochlorite > Green Colored Complex whoose absorbance is read at 570nm

47. In human, uric acid is the major product of the catabolism of the purine nucleosides, adenosine and guanosine . Purines are derived from catabolism of dietary nucleic acid and from degradation of endogenous nucleic acids. Overproduction of uric acid may result from increased synthesis of purine precursors. In humans, approximately 75% of uric acid excreted is lost in the urine; most of the reminder is secreted into the GIT

48. Renal handling of uric acid is complex and involves four sequential steps: – Glomerular filtration of virtually all the uric acid in capillary plasma entering the glomerulus . – Reabsorption in the proximal convoluted tubule of about 98 to 100% of filtered uric acid. – Subsequent secretion of uric acid into the lumen of the distal portion of the proximal tubule. – Further reabsorption in the distal tubule. Hyperuricemia is defined by serum or plasma uric acid concentrations higher than 7.0 mg/dl (0.42mmol/L) in men or greater than 6.0 mg/dl (0.36mmol/L) in women

49. Glomerular function tests The GFR is the best measure of glomerular function. Normal GFR is approximately 125 mL /min When GFR decreases to 30% of normal moderate renal insufficiency. Patients remain asymptomatic with only biochemical evidence of a decline in GFR As the GFR decreases further severe renal insufficiency characterized by profound clinical manifestations of uremia and biochemical abnormalities, such as acidemia ; volume overload; and neurologic, cardiac, and respiratory manifestations When GFR is 5% to 10% of normal ESRD

50. Inulin clearance and creatinine clearance are used to measure the GFR. Creatinine Clearance: A simple, inexpensive bedside estimate of GFR. GFR= Ccr = { Ucr * Urinary flow rate(ml/min)} / Pcr Normal 100-120ml/min Dec.Renal reserve 60-100ml/min Mild Renal imp 40-60ml/min Moderate insuff . 25-40ml/min Renal failure <25ml/min ESRD <10ml/min

51. Cockroft Gault Formula Creatinine Clearance =(140-age)* weight in kg / S.creat .*72 (multiplied by 0.85 for females) MDRD Nomogram GFR(ml/min)=170*S.creat.-0.999 *age-0.176 * BUN-0.170 *albumin0.318 (multiplied by 0.742 if female)