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URINE INTERPRETATION URINE EXAMINATION A properly performed examination of urine can produce a great deal of useful information about patient's; Metabolic functions. Functional Integrity of the organs. Ingestion of drugs and poisons. HOW TO COLLECT THE SPECIMEN HOW TO COLLECT THE SPECIMEN . An accurately timed, properly collected and well preserved specimen is essential. Neglect of this aspect of examination frequently renders all subsequent information uninterpretable or useless METHODS OF URINE COLLECTION Random collection of Speciman Taken at any time of day with no precautions regarding contamination. The sample may be dilute, isotonic, or hypertonic and may contain white cells, bacteria, and squamous epithelium as contaminants. In females, the specimen may contain vaginal contaminants such as trichomonads, yeast, and during menses, red cells. Early morning collection of the sample: First morning specimen, before ingestion of any fluid, which is fresh, concentrated and with acid pH, is considered the best one. This is usually hypertonic and reflects the ability of the kidney to concentrate urine during dehydration which occurs overnight. Clean-catch, midstream urine specimen: collected after cleansing the external urethral meatus.. A midstream urine is one in which the first half of the bladder urine is discarded and the collection vessel is introduced into the urinary stream to catch the last half. The first half of the stream serves to flush contaminating cells and microbes from the outer urethra prior to collection. Catherization of the bladder through the urethra for urine collection is carried out only in special circumstances, i.e., in a comatose or confused patient. This procedure risks introducing infection and traumatizing the urethra and bladder, thus producing iatrogenic infection or hematuria. Suprapubic transabdominal needle aspiration of the bladder. When done under ideal conditions, this provides the purest sampling of bladder urine. This is a good method for infants and small children 24-HOUR URINE COLLECTION -should start from 7.00 a.m. after discarding the first voiding, till the next morning including the first sample before 7.00 a.m. Patient should urinate in a large bottle having appropriate preservative. The bladder should be emptied into this bottle before going for defecation PHYSICAL EXAMINATION OF THE URINE PHYSICAL EXAMINATION Color Color and clarity of the urine is examined at first. Freshly voided normal urine is clear to slightly hazy with yellow color due to the pigments urochrome and `urobilin'. Intensity of color depends upon the degree of concentration. Very dilute urine is almost colorless while concentrated urine is dark yellow or amber in color. Turbidity usually results from crystallization or precipitation of urates (in acid urine) or phosphate (in alkaline urine). PATHOLOGICAL AND NON PATHOLOGICAL CAUSES OF COLOUR CHANGES Color Pathological cause Non Pahtological Cause Red Haemoglobulin Myoglbulin Porphyrin Many drugs and dyes like Rifampicin,beets Orange Bile Pigments Yellow Concentrated urine Bilirubin Urobilin Carrots Nitrfurantion Green Bacteria Specially Pseudonomas Vitamins Preparation Some Diruetics Black or Brownish Melanin Homogentisic acid Indicans Urobilin Met Haemoglobin Levodopa Cascara Iron complexes Phenols VOLUME On random collections, volume estimation is irrelevant but with timed specimen such as hourly or 24 hour urine specimen, volume must be estimated and noted. CHEMICAL URINE EXAMINATION PH Specific gravity Sugar Haemoglobin (blood) Protein Urobilinogen Bilirubin Ketones Leukocyte esterase Nitirite Bilirubin Urobilinogen PH NORMAL URINE The pH of normal urine is acidic. It is usually between 5 and 7. Normal pH range in urine 0 - 7 acid 7 neutral 7 - 14 alkaline Bacterial contamination or drugs may make the urine alkaline in reaction. . Diet can be used to modify urine pH. A high-protein diet or consuming cranberries will make the urine more acidic. A vegetarian diet, a low-carbohydrate diet, or the ingestion of citrus fruits will tend to make the urine more alkaline Abnormal pH values may indicative of Persistent alkaline urine (pH 7 - 8) suggests urinary tract infection vegetarian diet alkalosis pyloric stenosis / obstruction vomiting alkalizing drugs Persistent acid urine (pH 5 - 7) gout fever phenacetin intake predisposition to uric acid calculi (kidney stones) SPECIFIC GRAVITY The specific gravity of normal urine varies between 1.005 to 1.025 depending upon diet and intake of fluids. Specific gravity measurements are actually a comparison of the amount of solutes (substances dissolved) in urine as compared to pure water. This test simply indicates how concentrated the urine is. If a person drinks excessive quantities of water in a short period of time or gets an intravenous (IV) infusion of large volumes of fluid, then the urine SG may be as low as 1.002. The upper limit of the test pad, an SG of 1.035, indicates a concentrated urine, one with many solutes in a limited amount of water. ABNORMAL SPECIFIC GRAVITY VALUES MAY INDICATIVE OF Reduced specific gravity Raised specific gravity diabetes insipidus certain renal diseases excess fluid intake diabetes mellitus dehydration adrenal insufficiency nephrosis congestive cardiac-failure liver disease Constant specific gravity chronic renal disorder PROTEIN The protein test measures the amount of albumin in the urine. Normally, there will not be detectable quantities. When urine protein is elevated, you have a condition called proteinuria; this can be an early sign of kidney disease. Albumin is smaller than most other proteins and is typically the first protein that is seen in the urine when kidney dysfunction begins to develop. Other proteins are not detected by the test pad but may be measured with a separate urine protein test. Other conditions that can produce proteinuria include: Disorders that produce high amounts of proteins in the blood, such as multiple myeloma Conditions that destroy red blood cells Inflammation, malignancies (cancer), or injury of the urinary tract - for example, the bladder, prostate, or urethra Vaginal secretions that get into urine Proteins appear in the urine after severe exercise and prolonged standing (Orthostatic Proteinuria). ABNORMAL PROTEIN VALUES MAY INDICATIVE OF Proteinuria may be benign or pathological Benign proteinuria Pathological proteinuria External postural excessive exercise high or low temperature during pregnancy colic liver cirrhosis plasmacytoma cardiac insufficiency Renal pyelonephritis glomerulonephritis GLUCOSE Glucose is normally not present in urine. When glucose is present, the condition is called glucosuria. It results from either: An excessively high glucose concentration in the blood, such as may be seen with people who have uncontrolled diabetes mellitus A reduction in the “renal threshold.” When blood glucose levels reach a certain concentration, the kidneys begin to excrete glucose into the urine to decrease blood concentrations. Sometimes the threshold concentration is reduced and glucose enters the urine sooner, at a lower blood glucose concentration. Some other conditions that can cause glucosuria include hormonal disorders, liver disease, medications, and pregnancy. When glucosuria occurs, other tests such as blood glucose are usually performed to further identify the specific cause BLOOD (HEMOGLOBIN) This test is used to detect hemoglobin in the urine (hemoglobinuria). Hemoglobin is a oxygen-transporting protein found inside red blood cells (RBCs). Its presence in the urine indicates blood in the urine (known as hematuria). The small number of RBCs normally present in urine (microscopic examination) usually result in a "negative" test. However, when the number of RBCs increases, they are detected as a "positive" test result. Even small increases in the amount of RBCs in urine can be significant. Numerous diseases of the kidney and urinary tract, as well as trauma, medications, smoking, or strenuous exercise can cause hematuria or hemoglobinuria. This test cannot determine the severity of disease nor be used to identify where the blood is coming from. For instance, contamination of urine with blood from hemorrhoids or vaginal bleeding cannot be distinguished from a bleed in the urinary tract. This is why it is important to collect a urine specimen correctly and for women to tell their health care provider that they are menstruating when asked to collect a urine specimen. Sometimes a chemical test for blood in the urine is negative, but the microscopic examination shows increased numbers of RBCs. When this happens, the laboratorian may test the sample for ascorbic acid (vitamin C), because vitamin C has been known to interfere with the accuracy of urine blood test results, causing them to be falsely low or falsely negative KETONES Ketones (acetone, aceotacetic acid, betahydroxybutyric acid) may be present in diabetic ketosis or other forms of calorie deprivation (e.g. starvation). Ketones are easily detected using either dipsticks or test tablets containing sodium nitroprusside Ketones in urine-When ketones are found during a urine test, further investigation is required to ascertain your true health status. Normal ketones range in urine-negative Measuring range-0 - 160 mg/dl Ketones levels in urine They are produced in the body when fats, rather than glucose are used to produce energy. This substance is an acid which can be harmful to the body if ketones are allowed to accumulate. Abnormal ketones values may indicative of Diabetic ketoacidosis Insufficient food intake Nausea and vomiting Starvation Strict dieting Severe stress Severe fever due to infection NITRITE This test detects nitrite and is based upon the fact that many bacteria can convert nitrate to nitrite in your urine. A positive nitrite test result can indicate a UTI. However, since not all bacteria are capable of converting nitrate to nitrite, you can still have a UTI despite a negative nitrite test. BILIRUBIN Bilirubin is not present in the urine of normal, healthy individuals. Bilirubin is a waste product that is produced by the liver from the hemoglobin of RBCs that are removed from circulation. It becomes a component of bile, a fluid that is secreted into the intestines to aid in food digestion. In certain liver diseases, such as biliary obstruction or hepatitis, bilirubin leaks back into the blood stream and is excreted in urine. The presence of bilirubin in urine is an early indicator of liver disease and can occur before clinical symptoms such as jaundice develop Normal bilirubin range in urine up to 3 umol/l Measuring range negative, +, ++, +++ Bilirubin levels in urine Hemoglobin (haemoglobin) breakdown results in bilirubin production. In the liver, bilirubin is conjugated to an acid to make conjugated bilirubin. Unconjugated bilirubin is water soluble and can therefore be excreted in urine. Abnormal bilirubin values may indicative of Pre-hepatic (unconjugated bilirubin therefore does not appear in urine) Hepatic anemia's excessive breakdown of RBC hepatitis cirrhosis obstruction of biliary duct toxic liver damage Post-hepatic biliary tree obstruction UROBILINOGEN Urobilinogen is normally present in urine in low concentrations. It is formed in the intestine from bilirubin, and a portion of it is absorbed back into the bloodstream. Positive test results help detect liver diseases such as hepatitis cirrhosis and conditions associated with increased RBC destruction (hemolytic anemia). When urine urobilinogen is low or absent in a patient with urine bilirubin and/or signs of liver dysfunction, it can indicate the presence of hepatic or biliary obstruction he Microscopic Examination A microscopic examination may or may not be performed as part of a routine urinalysis. It will typically be done when there are abnormal findings on the physical or chemical examination. It is performed on urine sediment – urine that has been centrifuged to concentrate the substances in it at the bottom of a tube. The fluid at the top of the tube is then discarded and the drops of fluid remaining are examined under a microscope. Cells, crystals, and other substances are counted and reported either as the number observed "per low power field" (LPF) or "per high power field" (HPF). In addition, some entities, if present, are estimated as "few," "moderate," or "many," such as epithelial cells, bacteria, and crystals. RED BLOOD CELLS (RBCS) Normally, a few RBCs are present in urine sediment. Inflammation, injury, or disease in the kidneys or elsewhere in the urinary tract, for example, in the bladder or urethra, can cause RBCs to leak out of the blood vessels into the urine. RBCs can also be a contaminant due to an improper sample collection and blood from hemorrhoids or menstruation. RED BLOOD CELLS The finding of more than one or two red blood cells per high power field is an abnormal condition. It indicates following diseases: Renal or systemic disease . Trauma to the kidney Increased red cells occur in; . Pyelonephritis . Lupus Renal stones. Cystitis . Prostatitis Tuberculosis and malignancies of the genitourinary tract. Haemophilia Red cells in excess of WBCs in urine indicate bleeding into the urinary tract as may occur in; Aspirin ingestion . Anticoagulative therapy Thrombocytopenia Red blood cells may be found in the urine following violent exercise or they may be due to the contamination by menstrual flow. Normal range less than 3 ery/ul Measuring range blood 5 - 250 ery/ul hemoglobin (haemoglobin) 10 - 250 ery/ul Levels in urine Detections of blood cells or hemoglobin (haemoglobin) in urine as it is of pathological significance Abnormal values may indicative of Hematuria (haematuria) Hemaglobinuria (haemaglobinuria) (hemoglobin in urine) kidney and bladder calculi damage to kidney or urinary tract breakdown of red blood cells poisoning Myoglobinuria myocardial infarct muscle damage WHITE BLOOD CELLS (WBCS) The number of WBCs in urine sediment is normally low. When the number is high, it indicates an infection or inflammation somewhere in the urinary tract. WBCs can also be a contaminant, such as those from vaginal secretions. Leukocytes levels in urine This test indicates whether white blood cells are present in urine. pathological concentration: more than 20 leu/ul. Abnormal leukocytes values may indicative of Cardinal symptom of urinary tract infection kidney infection cystitis urethritis Contamination vaginal secretion EPITHELIAL CELLS Normally in men and women, a few epithelial cells from the bladder (transitional epithelial cells) or from the external urethra (squamous epithelial cells) can be found in the urine sediment. Cells from the kidney (kidney cells) are less common. In urinary tract conditions such as infections, inflammation, and malignancies, more epithelial cells are present. Determining the kinds of cells present helps the health care provider pinpoint where the condition is located. For example, a bladder infection may result in large numbers of transitional epithelial cells in urine sediment. Epithelial cells are usually reported as "few," "moderate," or "many" present per low power field (LPF). MICROORGANISMS (BACTERIA, TRICHOMONADS, YEAST) In health, the urinary tract is sterile; there will be no microorganisms seen in the urine sediment. Microorganisms are usually reported as "none," "few," "moderate," or "many" present per high power field (HPF). Special care must be taken during specimen collection, particularly in women, to prevent bacteria that normally live on the skin or in vaginal secretions from contaminating the urine. A urine culture may be performed if a UTI is suspected. In women (and rarely in men), yeast can also be present in urine. They are most often present in women who have a vaginal yeast infection, because the urine has been contaminated with vaginal secretions during collection. If yeast are observed in urine, then tests for a yeast (fungal) infection may be performed on vaginal secretions CASTS Casts are cylindrical particles sometimes found in urine that are formed from coagulated protein secreted by kidney cells. They are formed in the long, thin, hollow tubes of the kidneys known as tubules and usually take the shape of the tubule (hence the name). Under the microscope, they often look like the shape of a "hot dog" and in healthy people they appear nearly clear. This type of cast is called a "hyaline" cast. When a disease process is present in the kidney, other things such as RBCs or WBCs can become trapped in the protein as the cast is formed. When this happens, the cast is identified by the substances inside it, for example, as a red blood cell cast or white blood cell cast. Different types of casts are associated with different kidney diseases, and the type of casts found in the urine may give clues as to which disorder is affecting the kidney. Some other examples of types of casts include granular casts, fatty casts, and waxy casts. Normally, healthy people may have a few (0–5) hyaline casts per low power field (LPF). After strenuous exercise, more hyaline casts may be detected. Cellular casts, such as RBC and WBC casts, indicate a kidney disorder WHITE BLOOD CELLS AND WHITE CELL CASTS White blood cells in urine in large numbers ->indicate bacterial infection in the urinary tract. If the infection is in the kidney, the white cells tend to be associated with cellular and granular casts, bacteria, epithelial cells and relatively few red cells. CRYSTALS Urine contains many dissolved substances (solutes) – waste chemicals that your body needs to eliminate. These solutes can form crystals, solid forms of a particular substance, in the urine if: the urine pH is increasingly acidic or basic; the concentration of dissolved substances is increased; andthe urine temperature promotes their formation. Crystals are identified by their shape, color, and by the urine pH. They may be small, sand-like particles with no specific shape (amorphous) or have specific shapes, such as needle-like. Crystals are considered "normal" if they are from solutes that are typically found in the urine. Some examples of crystals Normally in acid urine calcium oxalate, uric acid and urates are found while in alkaline urine amorphous phosphates, calcium phosphates, triple phosphate and ammonium bicarbonate crystals are found. The presence of cystine, leucine or tyrosine and cholesterol crystals indicate metabolic abnormalities. Drug crystal are also found in the urine such as sulphonamide crystals. CONCLUSION COLLECTION OF SPECIMEN FOR CULTURE Early morning specimen should be obtained whenever possible because the bacterial count is the highest at that time. A sterile container should be used. Proper aseptic measures should be adopted to obtain a midstream urine specimen. Two successive clean voided or midstream specimen should be collected in order to be 95% certain that bacteriuria is present. Urine is an excellent culture medium, which at room temperature allows the growth of many organisms. Collection of specimen therefore, should be as aseptic as possible. Sample should be sent immediately to the laboratory where it can be examined while still warm. If prompt analysis is MICROBIOLOGICAL EXAMINATION Urine in normal individuals does not contain micro organisms. However the titre of less than 10,000 organisms/ml is considered normal. It may be due to contamination. infection by organisms introduced through the urethra. Acute infections are more common in females than in males because of shorter urethra and greater likelihood of its becoming contaminated. Infections are usually associated with bacterial counts of 100,000 or more organisms per ml of urine (this level indicates the significant bacteriuria). The condition of pyuria (pus in the urine) and significant bacteriuria strongly suggest the diagnosis of urinary tract infection. Urine cultures are most commonly used to diagnose a bacterial infection of the urinary tract.