Lecture Lesson 3. Physical Examination of Urine PDF

ANALYSIS OF URINE AND BODY FLUIDS (LECTURE) FACTORS AFFECTING URINE COLOR 1. Specimen Evaluation the amount of the substance present 2. Physical Examination...

ANALYSIS OF URINE AND BODY FLUIDS (LECTURE) FACTORS AFFECTING URINE COLOR 1. Specimen Evaluation the amount of the substance present 2. Physical Examination the urine pH 3. Chemical Examination o some pigments when exposed to 4. Sediment Examination alkaline environment results darker color o Ex. alkaptonuria (melanin pigment gives - Rough indicator of the degree of hydration dark brown color to the urine) - Depends primarily on the body’s homeostasis the structural form of the substance and the degree of hydration - Should correlate with the urine Specific Gravity LABORATORY CORRELATIONS OF URINE COLOR - Low fluid intake = darker urine color = higher Normal Urine Color amount of solute = increased specific gravity Colorless/Straw – recent fluid consumption - High fluid intake = lighter urine color = lower Pale yellow amount of solute = decreased specific gravity o Dilute random specimen - Normal: Colorless (straw) to Deep Yellow o Polyuria - Abnormal: Red/Red-Brown (Most Common) ▪ Diabetes mellitus: increased glucose and water excretion Recommendations for the Evaluation of Urine ▪ Diabetes insipidus: deficiency in Physical Characteristics antidiuretic hormone Use a well-mixed specimen Water will be excreted View through a clear container – plastic or glass. even the patient is View against a white background. already dehydrated Evaluate a consistent depth or volume of the ▪ Both has Increased water specimen. excretions View using room lighting that is adequate and ▪ More than 2 liters per day consistent. Dark Yellow o Concentrated specimen URINE PIGMENTS o Depends on the increased urochrome o Dehydration Urochrome o Strenuous exercise - product of endogenous metabolism o First morning urine specimen - Major pigment ▪ Pale yellow first morning urine if - Yellow pigment the patient has diabetes - It is a lipid-soluble pigment insipidus - Increased metabolism = increased urochrome o ex. hyperthyroidism, starvation, and Urine Color Chart fever Urine Color Possible Meaning - Constantly produced by the body Good hydration, overhydration, or mild Clear - Present normally in the body and is excreted in dehydration the urine Pale Yellow Good hydration or mild dehydration Mild or moderate dehydration or taking - Patient with renal disease, failure, or CKD may Bright Yellow vitamin supplements not excrete urochrome Orange, Amber Moderate or severe dehydration o The filtering capacity of kidney is Tea-Colored Severe dehydration or burned patients damaged o The urochrome will be deposited under Abnormal Urine Color the skin (subcutaneous fats), causing Dark Yellow/Amber/Orange yellowish pigmentation of skin o Presence of the abnormal pigment bilirubin Uroerythrin ▪ a yellow foam appears when the - May deposit in amorphous urates and uric acid specimen is shaken, may contain crystals hepatitis virus - Pink pigment ▪ yellow foam sometimes due to - Smaller in quantity compared to urochrome medications (Phenazopyridine) - Does not always evident ▪ Bilirubin increases when there is - Seen when sample is centrifuged a liver problem - Has reddish or brick-red crystals ▪ It should be converted to urobilinogen Urobilin ▪ Bilirubin is sensitive to light - Imparts an orange-brown color of urine that is o Photo-oxidation of large amounts of not fresh excreted urobilinogen to urobilin (no - Oxidized form of urobilinogen yellow foam when shaken) - Old urine specimen  ANALYSIS OF URINE AND BODY FLUIDS (LECTURE) Yellow-Green Purple o Biliverdin (photo-oxidation of bilirubin) o Found in catheter bags o Upon standing or improper storage, o Associated with purple bag syndrome bilirubin may be oxidized to biliverdin and blue diaper syndrome (in infant Yellow-orange patients with indicanuria) o Phenazopyridine (Pyridium) or o Presence of indican (water soluble) azogantrisin (produce a yellow foam o Presence of indole gives purple color when shaken) ▪ Tryptophan converts into ▪ Treatment for UTI indole, which further converts o also interferes with chemical tests that into indican, causing indicanuria are based on color reactions o Bacterial infection o high consumption of food such as ▪ Klebsiella or Providencia species vegetables rich in beta carotene Brown/Black Red/Pink/Brown o Methemoglobin: oxidized form of o One of the most common causes of hemoglobin in acidic urine abnormal urine color o Melanin o How to differentiate: ▪ oxidation product of melanogen ▪ Intact RBC: cloudy red or pink (colorless) ▪ Hemolyzed RBCs (hemoglobin ▪ produced in excess when a or myoglobin): clear red malignant melanoma is present Plasma Examination Test o Homogentisic acid: metabolite of Hemoglobin Red or pink phenylalanine (alkaptonuria) Myoglobin Clear yellow ▪ The sample become alkaline o Blood may range from pink to brown, upon standing depending on o Medications: include levodopa, ▪ the amount of blood methyldopa, phenol derivatives, and ▪ the pH of the urine metronidazole (Flagyl). ▪ the length of contact o oxidation of hemoglobin to Urine color changes with commonly used drugs methemoglobin (brown) Drug Effect o Fresh brown (glomerular bleeding) Levodopa Cola-colored, due to myoglobin o Alkaline urine with red blood cell gives Mepacrine (Atabrine) Yellow reddish brown in color Methyldopa (Aldomet) Green-brown Porphyrin: Oxidation of porphobilinogen (port Metronidazole (Flagyl) Darkening, reddish brown Phenazopyridine (Pyridium) Orange-red, acidic pH wine, Burgundy red, Purplish Red) Rifampin Bright orange-red o Disorder in the porphyrin metabolism Riboflavin Bright yellow o The pigment also deposited in teeth o Patients before are thought to be vampires (pale skin and bleeding mouth) o Non-pathogenic causes ▪ Menstrual contamination ▪ Ingestion of highly pigmented foods ▪ Medications (rifampin, phenolphthalein, phenindione, and phenothiazines) ▪ In genetically susceptible persons, eating fresh beets causes a red color in alkaline urine ▪ Ingestion of blackberries can produce a red color in acidic urine Blue/Green o Bacterial infections ▪ urinary tract infection by Pseudomonas species, which gives pyoveridin pigment o Intestinal tract infections o Ingestion of breath deodorizers (clorets) o Excessive use of mouthwash o Phenol derivatives produce green urine on oxidation o Medication (blue) ▪ Methocarbamol (Robaxin) ▪ Methylene blue ▪ Amitriptyline (Elavil)  ANALYSIS OF URINE AND BODY FLUIDS (LECTURE) - Other causes: - Normal Range (24 hours): 600 mL to 2000 mL o Diabetes mellitus (glucose) - Average (24 hours): 1200 to 1500 mL o Drugs (diuretic therapy, caffeine, - Night:Day Ratio: 1:2 or 1:3 alcohol) - Depends on: o Excessive fluid intake (IV administration, o Amount of water the kidneys excrete compulsive water intake) o Body’s state of hydration o Diabetes insipidus (ability to retain - Factors that influence urine volume: water is lost) o Fluid intake o Renal disease o Fluid loss from non-renal sources o Drugs (lithium) (diarrhea, 3rd degree burn, excessive vomiting, and excessive sweating) o Variations in the excretion of Antidiuretic hormone (diabetic insipidus) o Need to excrete increased amount of dissolved solids OLIGURIA - decrease in urine output - Body enters a state of body dehydration Renal threshold: 160 to 180 mg/dL - Ranges: Hypothalamic Nephrogenic o Infants: < 1mL/kg/hr complete deficiency ADH is present, but the cells in o Children: 2000 mL/24 hours (Strasinger) o Children: 2.5–3 mL/kg/day - often associated with diabetes mellitus and diabetes insipidus - artificially induced by diuretics, caffeine, or alcohol o all suppress the secretion of antidiuretic hormone  ANALYSIS OF URINE AND BODY FLUIDS (LECTURE) CAUSES OF URINE TURBIDITY - Obsolete method because it requires large Nonpathologic Pathologic volume of sample (10-15mL) Squamous epithelial cells RBCs - There should be a correction to be done because Mucus WBCs of the presence of certain solutes Amorphous phosphates, - Calibration Temperature: 20°C Bacteria carbonates, urates - Requires Temperature correction: Semen, spermatozoa Yeast Fecal contamination Nonsquamous epithelial cells o – 0.001 for every 3°C that the specimen Radiographic contrast media Abnormal crystals temp is below the calibrating temp Talcum powder Lymph fluid o + 0.001 for every 3°C that the specimen Vaginal creams Lipids temp is above the calibrating temp - Requires solute correction: LABORATORY CORRELATIONS IN URINE TURBIDITY o 1 g/dL Glucose = – 0.004 Acidic Urine o 1 g/dL Protein = – 0.003 o Amorphous urates o Radiographic contrast media Example Alkaline Urine A specimen containing 1 g/dL protein and 1 g/dL glucose o Amorphous phosphates, carbonates has a specific gravity reading of 1.030. Soluble with Heat Specimen Temp Reading: 26°C o Amorphous urates, uric acid crystals Calculate the corrected reading: Soluble in Dilute Acetic Acid 1.030 – 0.003 (protein) = 1.027 o RBCs 1.027 – 0.004 (glucose) = 1.023 o Amorphous phosphates, carbonates 1.023 + 0.002 (temp) = 1.025 Insoluble in Dilute Acetic Acid 1.025 = corrected specific gravity o WBCs (add 2 drops of acetic acid) o Bacteria, yeast REFRACTOMETER o Spermatozoa - Determines the concentration of dissolved Soluble in Ether particles in a specimen o Lipids - Measures refractive index (a comparison of the o Lymphatic fluid, chyle velocity of light in air with the velocity of light in a solution) - Use only small volume of specimen (one or two - Specific gravity (SG) is an expression of urine drops). concentration in terms of density - Temperature corrections are not necessary - Detects possible dehydration or abnormalities in (15°C and 38°C) antidiuretic hormone. - solute correction is needed - Measure of the density of the dissolved chemicals in the specimen - Direct methods using a urinometer (hydrometer) or harmonic oscillation densitometry (HOD) o To check the total solid present directly from the urine sample - Indirect methods using a refractometer or the chemical reagent strip. o To check the refractive index (refractometer) and amount of ions (chemical reagent strip) instead of solutes - Specific Gravity of Urine: 1.003 to 1.035 - Average Specific Gravity of Urine: 1.015 to 1.030 𝐷𝑒𝑛𝑠𝑖𝑡𝑦 𝑜𝑓 𝑈𝑟𝑖𝑛𝑒 SG = 𝐷𝑒𝑛𝑠𝑖𝑡𝑦 𝑜𝑓 𝑒𝑞𝑢𝑎𝑙 𝑣𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑝𝑢𝑟𝑒 𝑤𝑎𝑡𝑒𝑟 Particle Changes to Colligative Properties Normal Pure Effect of 1 Mole Property Water Point of Solute Freezing Point 0°C Lowered 1.86°C Boiling Point 100°C Raised 0.52°C 2.38 mm/Hg at Lowered 0.3 mm/Hg Vapor Pressure 25°C at 25°C Increased 1.7x109 Osmotic Pressure 0 mm/Hg mm/Hg URINOMETER - Urinometry is less accurate than the other methods currently available and is not recommended by the CLSI  ANALYSIS OF URINE AND BODY FLUIDS (LECTURE) - Due to organic and inorganic substances (byproducts of metabolism) - Normal urine has a characteristic aromatic odor that is typically faint and unremarkable - Urine odor led to the discovery of Phenylketonuria Common Causes of Urine Odor Odor Cause Normal Aromatic Caused by urea Bacterial decomposition, urinary tract infection Foul, ammonia-like Normal when the urine sample standing for a long time Ketones (product of lipid metabolism) Associated with diabetes mellitus, Fruity, sweet starvation, and vomiting Grapelike-odor, caramelized sugar, and curry odor Calibration Maple syrup Maple syrup urine disease Mousy Phenylketonuria SG Solution Rancid Tyrosinemia 1.000 Water, distilled Sweaty feet Isovaleric acidemia 1.015 NaCl, 0.513 mol/L (3% w/v) Cabbage Methionine malabsorption 1.022 NaCl, 0.856 mol/L (5% w/v) Bleach Contamination 1.034 Sucrose, 0.263 mol/L (9% w/v) Rotting Fish Trimethylaminuria Swimming pool Hawkinsinuria HARMONIC OSCILLATION DENSITOMETRY - accurate and precise in determining the urine specific - checks specific gravity up to 1.080 - one of the method used in semi-automated station - Based on the principle that the frequency of a sound wave entering a solution changes in proportion to the density of the solution o High sound frequency = high solute present - Shifts in harmonic oscillation are measured, and relative density is calculated - Yellow iris system: an automated urinalysis work station wherein it is used from chemical up to microscopic (slideless microscope) o Uses 6mL of sample: 4mL for slideless microscope and 2mL for mass gravity meter Urine Specific Gravity Measurements Method Principle Urinometry Density Refractometry Refractive Index Harmonic Oscillation Density Densitometry pKa changes of a Reagent Strip polyelectrolye