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ANALYSIS OF URINE AND OTHER BODY FLUIDS MLS 3A Module 2 Introduction to Urinalysis Egyptian hieroglyphics (Edwin Smith Surgical...
ANALYSIS OF URINE AND OTHER BODY FLUIDS MLS 3A Module 2 Introduction to Urinalysis Egyptian hieroglyphics (Edwin Smith Surgical Papyrus) LESSON 1: OVERVIEW OF URINALYSIS ○ a person referred to as an early scientist examining a bladder-shaped flasks of Urinalysis and body fluid analysis are performed in the clinical urine ○ obtained diagnostic information through laboratory as part of the healthcare organization. It generally basic observations employs three basic procedures: Hippocrates wrote his book on “uroscopy”, early physicians concentrated their efforts in uroscopy Physical examination - analysis of the visual as part of their training. characteristics of urine Frederik Dekker’s discovery of albuminuria in Chemical examination - detection of chemical analytes 1964 by boiling urine (showed clumping of in urine proteins due to coagulation/ denaturation in high Microscopic examination - identification of insoluble temperature) ○ During that time, “Ant testing” and “taste solutes in urine testing” are methods used in determining glucose in urine The Oxford Encyclopedic English Dictionary defines it as the Thomas Bryant wrote his book in 1627 about analysis of urine by physical, chemical and microscopic means Charlatans (pisse prophets), performing to test for the presence of drugs, diseases, etc. urinalysis & lab. examinations w/ out scientific background WHY URINE IS CONSIDERED A VALUABLE AND ○ credibility of urinalysis became POPULAR SPECIMEN? compromised Readily available and easily collected ○ the book revealed that Charlatans Contains information which is important in performed laboratory tests just for money screening discrepancies in the body’s major ○ however, it inspired the passing of first metabolic functions medical licensure laws in England Performed using inexpensive laboratory tests (contribution of urinalysis to the medical field) Thomas Addis and his method of quantifying LESSON 2: HISTORY OF URINALYSIS microscopic sediment (Addis Count). HISTORY OF URINALYSIS Richard Bright introduced the concept of urinalysis as part of a doctor’s routine patient Analyzing urine was the beginning of laboratory examination medicine. ○ Urinalysis has since then remained an integral part of patient examination. ANALYSIS OF URINE AND OTHER BODY FLUIDS MLS 3A Module 2 Unique Characteristics of Urine that gained it Presence of Renal Tubular Epithelial (RTE) cells popularity and squamous epithelial cells in microscopic examination 1. Urine is readily available and easily collected 2. Urine contains information on the body’s metabolic functions. LESSON 4: SPECIMEN INTEGRITY Urine as Valuable Specimen LESSON 3: URINE COMPOSITION - Readily available and easily collected URINE COMPOSITION - Info regarding metabolic function Urine is composed of 95% water and 5% solutes.The concentrations of these solutes have considerable variations - Inexpensive laboratory test owing to the influence of dietary intake, physical activity, body metabolism and endocrine functions. The following solutes are primary components in normal urine: SPECIMEN INTEGRITY Urea - metabolic waste product of breakdown of The performance of an accurate urinalysis begins with the protein and amino acids and the major organic proper collection technique. Several methods are implored component of urine depending on the type of specimen needed. Creatinine - product of creatine metabolism by muscles Uric acid - product of nucleic acid breakdown SPECIMEN COLLECTION Chloride - major inorganic component of urine Other electrolytes like sodium, potassium, o Clean, dry, leak-proof container phosphate, ammonium and calcium Other substances like hormones, vitamins and o Disposable containers medications o Properly-applied screw top lids Increased amounts of formed elements are indicative of disease o Wide mouth container to facilitate collection, wide flat bottom to prevent overturning, IMAGINE RECEIVING A COLORLESS FLUID IN THE leak-proof, screw top LABORATORY. HOW WILL YOU KNOW IF IT’S URINE? o Made of clear material and at least 50ml in High concentrations of urea and creatinine capacity Ammoniacal odor due to ammonia ANALYSIS OF URINE AND OTHER BODY FLUIDS MLS 3A Module 2 o Individually packaged sterile containers with collection and do not perform the procedure on secure closures for microbiologic assays the non matching labeled specimen o Urine “wee” bags with adhesive for collection o Urine is contaminated with feces or toilet of pediatric patients papers - may cause erroneous results in the examination of urine o Label must contain patient’s name, ID number, date and time of collection, and other info like o Contaminated exteriors of containers - patient’s age and location disregard and discard urine specimen o Label must be attached to the body of o Insufficient quantity - the minimum amount container and NOT on the cap should be 50 mL even if only 12mL is actually used. Extra urine will be used as needed o Specimen must be accompanied with a completely-filled requisition form o Improperly transported (2 hours left standing without addition of preservative or What should be indicated in the label? refrigeration) - A situation wherein urine is - Name collected at house and travelled at lab. If travel - Identification Number time exceeds two hours, and the specimen is not - Time and Date refrigerated or preserved, the specimen should - Additional info: Age, Location, Name of be rejected. The delayed urine sample is Healthcare Provider undesirable for urinalysis and may cause a series of reactions in the urine sample without preservative. SPECIMEN REJECTION SPECIMEN PRESERVATION Receiving the following specimen would require a medical Ideally, the specimen for routine urinalysis should be examined technologist to notify a senior staff. Unacceptable situations while fresh. In cases where the tests cannot be done promptly, would require collection of a new specimen and include the various changes occur in a specimen that remained following: unpreserved at room temperature for more than two hours. The following are commonly used preservatives should a specimen o Unlabeled containers - a “mortal sin in the be transported over a long distance. Lab” - request for new collection if identification conflicts arise o Refrigeration at 2-8 O C – most routinely used and impedes bacterial growth. No chemical o N onmatching labels and requisition forms - preservatives added if identification conflicts arise, request for new ANALYSIS OF URINE AND OTHER BODY FLUIDS MLS 3A Module 2 o Formalin- good preservative for sediments but Darkened coloration of urine precipitates proteins and acts as reducing Decreased clarity, glucose, ketones, bilirubin, agents (Disadvantages: may alter other chemical urobilinogen, formed elements analytes in urine like amounts of glucose and Increased ammoniacal odor, pH, nitrite and proteins) bacterial count o Toluene- preserves ketones, proteins and NOTE: reducing substances Decreased: o Thymol clarity o Chloroform- used for inhibiting bacterial bilirubin (via oxidation of bilirubin and growth urobilinogen once exposed to sunlight. Oxidized to biliverdin and urobilin, leading to o Boric acid- preserves sediments but interferes decreased bilirubin values) with pH readings glucose (increase because bacteria will o Chlorhexidine- glucose preservative and metabolize glucose for glycolysis) prevents bacterial growth ketones (known to be volatile (easy to evaporate), prolonged standing causes o Commercially-prepared preservative evaporation) tablets formed elements (disintegrate in prolonged standing) o Sodium fluoride- for drug analysis Increased: WHAT HAPPENS IN UNPRESERVED URINE AT ROOM TEMPERATURE FOR MORE THAN TWO HOURS? bacterial count increases because they thrive and multiply and they also reduce urea to ammonia, and ammonia causes ammoniacal urine odor. In addition, ammonia is the reason for increased urine pH (alkaline). Nitrite amount increases because of the conversion of nitrates (normal constituent of urine) due to the presence of bacteria. The urine color will also be modified (darkened). ANALYSIS OF URINE AND OTHER BODY FLUIDS MLS 3A Module 2 10. Place at a specified area or follow the institution's policy. TYPES OF SPECIMEN To obtain a specimen that is representative of a patient’s metabolic state, alteration in certain aspects of specimen collection is a must. These special considerations include time, length of collection, method, and patient’s dietary intake. A. Midstream Clean-Catch Specimen – method of choice for non-contaminated specimens ○ For Females: 1. Wash hands 2. Spread or separate the skin folds of the labia 3. Get an antiseptic towelette or use a hypoallergenic soap and clean the ○ For Males: urinary opening of the external 1. Wash hands genitalia. Cleans from front to back 2. Retract the foreskin if of both sides of the labia. uncircumcised 4. Open the container. Remove the 3. Get an antiseptic towelette or use a cover without touching the inside of hypoallergenic soap and clean the the container or the lid! urinary opening of the external 5. Urinate genitalia. Clean the tip of the penis - First part of the urine must (if uncircumcised, retract the be voided into the toilet foreskin. bowl. 4. Open the container. Remove the 6. After several seconds, bring the cover without touching the inside of urine container into the stream and the container or the lid! collect an adequate amount of 50 5. Urinate mL. - First part of the urine must 7. Void last part of the urine into the be voided into the toilet toilet bowl bowl. 8. Cover the specimen with the lid 6. After several seconds, bring the 9. Label the container at the side (not urine container into the stream and on the lid!) collect an adequate amount of 50 mL. ANALYSIS OF URINE AND OTHER BODY FLUIDS MLS 3A Module 2 7. Void last part of the urine into the with their hands. Bacteria may be toilet bowl present and cause a false negative 8. Cover the specimen with the lid result. 9. Label the container at the side (not - Can be used for routine urinalysis and on the lid!) bacterial culture. 10. Place at a specified area or follow - This is the most routinely performed type the institution's policy. of urine collection. B. Catheterized Specimen – urine is collected by passing through a hollow tube inserted through the urethra into the bladder - R equested for bacterial culture - External genitalia are washed prior to collection with mild antiseptic. Women should spread the labia while voiding. - Initial portion of urine is allowed to escape while the midstream portion is collected. First part is not included in the C. Suprapubic Aspiration – introduction of needle sample because of the probable through the abdomen into the bladder presence of bacteria that can contaminate the urine sample. - Doctor pulls the plunger and collect a While collecting the middle part sterile urine sample after several seconds. DO NOT - Most clean because it is directly collected touch the inside of the container or from the bladder. allow the container to touch any - Completely free of extraneous part of your genitalia. contamination - Final portion of urine is also discarded. - Used for bacterial culture and cytologic Possible contamination if the studies patient ever touched the genitalia ANALYSIS OF URINE AND OTHER BODY FLUIDS MLS 3A Module 2 Middle part is labelled as “middle” Before collecting the last portion, the doctor or urologist will massage the prostate gland located at the back of the rectum - This is to make sure the prostatic juice joins the urine into the final container. - last portion is labelled as “final” D. Three Glass Collection – used to determine prostatic infections - All portions of urine are collected in 3 separate containers (beginning, middle, final). - The prostate gland is massaged prior to collection in the third container. - Higher WBC and bacterial count in the third container compared to the first E. Pediatric Specimens – clean plastic bags container indicates prostatic infections. with hypoallergenic skin adhesive. Specimen - Second container serves as a control. But can be collected in two ways: if both the second container and third 1. Rub a piece of cotton on the container tested positive for bacteria and external genitalia of the baby (to WBC, the result is invalid. It only indicates stimulate urination), and catch the that the patient is suffering from urinary urine with a container. tract infection thus contaminating the third 2. Use of the pediatric bags container. - adhesive tape is sticked to Note: the navel of the baby and the bag opens directly to the First part of urine is labelled as genitalia. Wait for the “beginning” pediatric patient to urinate. ANALYSIS OF URINE AND OTHER BODY FLUIDS MLS 3A Module 2 Note: Does it need to be 50 mL? No! TIMING OF URINE SPECIMEN Special consideration must be done when o Random – most convenient but prone to the patient is an infant or pediatric, erroneous results because we cannot expect for them to excrete exactly 50 mL of urine. All we - Any time of the day have to do is take care of the amount of o First morning – ideal and preferred type for urine and make sure it is enough for routine urinalysis because it is more acidic and urinalysis. concentrated - many sediments can be seen - collected the moment the patient wakes up in the morning o 24-Hour or Timed Specimen – used in measuring exact amount of a urine chemical - The patient must begin and end with an empty bladder. For example: Doctor instructs the patient to collect the specimen at 7AM Saturday - 7AM Sunday. F. Drug Specimen Collection – all personnel Before 7AM on Saturday, the handling this specimen is documented patient must make sure he/she had peed already before the specified time (6:59) - A form called chain of custody (COC) is and discard. duly accomplished to document every step. By 7AM (Sat), patients must collect - Urine collection can either be witnessed ALL of their urine all throughout the day in or unwitnessed. a large water container. - Urine temperature must be taken 4 After 24 hours, the last urine of minutes after voiding and must fall between 7AM Sunday must be included and 32.5-37.7 O C. collected as a sample. ANALYSIS OF URINE AND OTHER BODY FLUIDS MLS 3A Module 2 - Upon arriving in the laboratory, the urine LESSON 5: PHYSICAL CHARACTERISTICS OF is mixed thoroughly and only an aliquot is URINE utilized for chemical testing. - Very useful in calculating hormones and Now, you are properly acquainted with the milestones electrolytes (catecholamines, and development of the practice of Routine Urinalysis. As future 17-hydroxysteroids) in which their medical laboratory scientists, the first part of urine analysis is concentration is greater in late afternoon the physical examination. This includes determination of urine and low in early morning. color, clarity, pH, volume, specific gravity and odor. The said characteristics are beneficial in the preliminary screening o Glucose Tolerance Specimens – concerning glomerular bleeding, liver diseases, inborn errors of corresponds with the glucose levels in blood metabolism and urinary tract infection. The visual results are samples also used to explain findings in the chemical and microscopic - Seldom performed in the laboratory. areas of urinalysis. - Done in conjunction with the blood URINE COLOR glucose - Urine and blood is taken at several The first physical characteristic is color. This is the best index to intervals (usually every 30 minutes). assess the concentration of urine. A noticeable change in color - Correlate the amount of sugar both in the is often due erroneous metabolic disorders thus alerting the blood and urine physician to request additional tests. The common descriptions fasting, 30-mins after ingestion of of colors include pale yellow, yellow and dark yellow. There are glucose load, three pigments responsible for the normal color: 1 hour after ingestion of glucose load Urochrome – product of body’s metabolism and 2 hours after ingestion of glucose increased in dehydration load - Responsible for yellow color in urine 3 hours after ingestion of glucose load Uroerythrin – attaches to urates thus giving pink color to the sediments Urobilin – product of oxidation of urobilinogen and gives an orange-brown color to urine that is not fresh ANALYSIS OF URINE AND OTHER BODY FLUIDS MLS 3A Module 2 o Green – infection with Pseudomonas aeruginosa o Blue-green – Clorets, ingestion of methylene blue, phenol, indican, Hartnup disease or Blue diaper syndrome; infection from Pseudomonas aeroginosa (contains green pigment) o Cloudy /Smoky red/ pink – Hematuria (intact RBCs) o Clear red/ pink – Hemoglobin (from urinary system damage), red pigments from beets or strawberries o Red-brown/Light-Brown – Myoglobin (from muscle breakdown in extreme exercise) o Purple - infection with Klebsiella or *the darker the urine, the more dehydrated you are. Providencia o Burgundy red/ Purplish-red/ Portwine – ABNORMAL URINE COLOR Porphyria, Lead poisoning o Colorless/ Pale yellow (Pale Straw) – o Brown/ Black – Homogentisic acid Polyuria due to diabetes mellitus/ diabetes (alkaptonuria, originally yellow before 30 minutes insipidus of standing), melanin, Methyldopa, Metronidazole, Argyrol, Phenol derivatives o A mber - Bilirubin -ingestion of fava beans o Orange-yellow - Pyridium (drug for UTI), Phenindione o Cola-colored – Methyldopa and Levodopa (drug for Parkinsonism) *Orange- Vitamin C, bilirubin (from liver disease), carotene (from carrots) overdose ;) o Bright yellow – Mepacrine/ Atabrine (treatment for malaria, Giardiasis), Riboflavin o Yellow-green – Bilirubin is oxidized to biliverdin o Bright orange-red – Rifampin (treatment for pulmonary tuberculosis) ANALYSIS OF URINE AND OTHER BODY FLUIDS MLS 3A Module 2 o Cloudy- white blood cells (urinary tract infection) A FORMERLY YELLOW URINE TURNED BLACK AFTER SEVERAL MOMENTS OF STANDING AT ROOM TEMPERATURE. WHAT IS THE REASON BEHIND THIS? In cases of alkaptonuria, homogentisic acid turns black once the pH of urine becomes alkaline. Prolonged standing of urine increase pH hence the term “alkali-lover”. ABNORMAL URINE CLARITY URINE CLARITY Presence of precipitates is common in urine samples. Determined by visually examining the specimen placed in Identification of these sediments is valuable in a test tube while holding it in front of a light source. determining if the cause of turbidity is pathologic or Most often, the clarity of urine could substantiate findings nonpathologic. in microscopical examination. There following terms are used to describe urine clarity: o Nonpathologic – presence of these 1. Clear substances is only caused by prolonged - refers to a transparent urine with standing, refrigeration of urine or improper no visible particulates. preservation 2. Slightly hazy/ Hazy - presence of few particulates floating but newsprint is still visible. 3. Cloudy - presence of many particulates. - newsprint is blurred. 4. Turbid - newsprint cannot be seen anymore 5. Milky - urine has clumped, coagulated, or precipitated. ANALYSIS OF URINE AND OTHER BODY FLUIDS MLS 3A Module 2 o Pathologic – indicates presence of infection TERMS USED TO DESCRIBE BASED ON SPECIFIC or metabolic disorders GRAVITY - NOTE: These are the important 1. Isosthenuria substances that must be reported in the - the SG of urine is 1.010 urinalysis result form. - also called Isosthenuric urine - indicates poor tubular reabsorption 2. Hyposthenuria - the SG of urine is below 1.010 - also called Hyposthenuric urine 3. Hypersthenuria - the SG of urine is above 1.010 - also called Hypersthenuric urine URINE SPECIFIC GRAVITY Refers to the ratio of the weight of a volume of urine to ABNORMAL SPECIFIC GRAVITY the weight of the same volume of distilled water at a Consistently high (1.020-1.035) constant temperature. Used to measure the concentrating and diluting ability of - Dehydration, proteinuria, glycosuria like the kidney to maintain homeostasis. diabetes mellitus, eclampsia, heart failure, The normal range of SG for random urine is 1.002-1.035. inappropriate secretion of antidiuretic The range for a 24-hour urine specimen is 1.015-1.025. hormone, dehydration, glomerulonephritis As discussed in Module 1, the ultrafiltrate of the plasma after being filtered by the glomerulus has a specific Abnormally high (above 1.040) gravity of 1.010. - Radiographic dyes, plasma expanders As ultrafiltrate passes through the renal tubules, it like dextran undergoes tubular reabsorption and tubular secretion resulting in the end product, urine. Consistently low (1.001-1.003) ○ NOTE: This is the reason why the SG of urine - Diabetes insipidus, diuretic medication, varies with that of the ultrafiltrate. pyelonephritis The two said processes alter the specific gravity of urine depending on the state of hydration and urine volume. ANALYSIS OF URINE AND OTHER BODY FLUIDS MLS 3A Module 2 In Diabetes Insipidus, there is decrease or loss of function of antidiuretic hormone which leads to excessive water loss by means of urination. ○ NOTE: As mentioned in module 1, ADH is responsible for reabsorption of water. ○ As a result: 1. Increased volume of urine 2. Diluted urine 3. Decreased specific gravity - due to more amounts of water than solutes. HOW CAN ONE DIFFERENTIATE DIABETES MELLITUS AND DIABETES INSIPIDUS? In Diabetes Mellitus, there is a defect in the pancreatic production of insulin which results in increased body glucose concentration. ○ NOTE: Insulin facilitates the entry of sugar in cells. ○ Increased body glucose exceeds renal threshold, triggering the body to remove excess glucose through urine. ○ As a result: 1. Increased volume of urine 2. Increased specific gravity - due to presence of glucose 3. Diluted urine - the body excreted more amounts of water to flush out glucose. ANALYSIS OF URINE AND OTHER BODY FLUIDS MLS 3A Module 2 METHODS IN MEASURING SPECIFIC GRAVITY OF Sample problem: URINE A laboratory report states that a o Reagent strip urinometer reading of urine’s specific gravity is 1.030. Correct the SG reading if the temp. Principle- pKa changes of a of urine is 26OC. polyelectrolyte by ions present Solution: 26OC is 6OC above 20OC o Urinometer - requires 10-15 ml of 26OC divided by 3OC is = 2 urine for every 3OC above 20OC, add 0.001 to - Composed of hydrometer the urine specific gravity 1.030 + (0.001 x 2) = 1.032 that is calibrated to measure SG at 20 O C - Employs the principle of buoyancy, so the urinometer will float Note: What if it is not divisible by 3? higher in urine than in water, because urine is denser. If 21OC or 22OC - since it didn't reach 23OC higher, there is no need to correct the SG. If lower than 20OC : 19OC or 18OC , there is no Note: One problem with a urinometer is that it is only need to to perform correction. limited to function at 20OC. That’s why we perform If 24OC or 25OC - since it didn't reach 26OC , it temperature correction. will fall at 23OC, wherein we will add only 0.001. - Requires temperature correction. For every 3 O C above 20 O C, add 0.001 to the urine’s SG. For every 3 OC below 20 O C, subtract 0.001 from the urine’s SG. - Requires protein and glucose correction. For every gram/dL of protein in urine, subtract 0.003 from the urine’s SG. For every gram/dL of glucose in urine, subtract 0.004 from the urine’ SG. ANALYSIS OF URINE AND OTHER BODY FLUIDS MLS 3A Module 2 Sample problem: A laboratory report states that a urinometer reading of urine’s specific gravity is 1.035. Correct the SG reading if the urine contains 2g/dL of glucose and 3 g/dL of proteins. Solution: Glucose: 2 g/dL x 0.004 = 0.008 Proteins: 3 g/dL x 0.003 = 0.009 0.008 + 0.009= 0.017 1.035 - 0.017 = 1.018 o Refractometer – requires 1-2 drops of urine - Employs the principle of refractive index, which is the ratio of the velocity of light in air to the velocity of light in urine - The path of light is deviated when it enters a solution, and the degree of refraction is equal to the urine’s SG. URINE VOLUME - No need for temperature correction. It is calibrated between 15-35 OC. The amount of urine excreted depends on the amount of water that the kidneys excrete. Factors responsible for this include the - Requires protein and glucose correction. body’s state of hydration, fluid intake, variations in antidiuretic For every gram/dL of protein in urine, hormone and the need to flush out excess body solids like subtract 0.003 from the urine’s SG. For every glucose or salts. The normal daily urine output is 1200-1500 gram/dL of glucose in urine, subtract 0.004 mL, with a range of 600-2000 mL still considered normal. from the urine’ SG. ANALYSIS OF URINE AND OTHER BODY FLUIDS MLS 3A Module 2 VARIATIONS IN URINE VOLUME URINE pH o Oliguria – decrease in urine output (2500 mL in adults) Although not usually done, sniffing urine odor could give us significant observation. The normal odor of freshly-voided urine is - Diabetes insipidus, diabetes mellitus, aromatic but prolonged standing could emit ammoniacal odor. The intake of diuretics like coffee and alcohol change in smell is brought about by the breakdown of urea to ammonia. Serious metabolic defects could be screened if the following odors are observed in a specimen. o Fruity, sweet – Diabetes mellitus due to ketones o Rotten fish/Galunggong – Trimethylaminuria o Sweaty feet – Isovaleric acidemia o Mousy – Phenylketonuria o Cabbage – Methionine malabsorption o Caramelized sugar, maple syrup – Maple Syrup Urine Disease o Bleach – Contamination o Sulfur – Cysteine disorder o Ammoniacal even though freshly-voided – Urinary tract infection
