Physical Examination of Urine PDF (Chapter 5)

6/20/2024 PHYSICAL EXAMINATION OF URINE CHAPTER 5 1 PREAMBLE  PowerPoints are a general overview and are provided to help students take notes over the video lecture ONLY.  PowerPoints DO NOT cover the details needed for the Unit exam  Each student is responsible fo...

6/20/2024 PHYSICAL EXAMINATION OF URINE CHAPTER 5 1 PREAMBLE  PowerPoints are a general overview and are provided to help students take notes over the video lecture ONLY.  PowerPoints DO NOT cover the details needed for the Unit exam  Each student is responsible for READING the TEXTBOOK for details to answer the UNIT OBJECTIVES  Unit Objectives are your study guide (not this PowerPoint)  Test questions cover the details of UNIT OBJECTIVES found only in your Textbook! 2 1  6/20/2024 URINALYSIS  Urinalysis has 3 sections of examination 1. Physical examination  Color, clarity, and specific gravity 2. Chemical (the dipstick portion)  Glucose, ketones, protein, pH, blood, bilirubin, urobilinogen, nitrates, and leukocytes 3. Microscopic  White & red cells, epithelial, crystal, cast, and other findings 3 INTRODUCTION  Physical examination of urine includes  Color  Clarity  Specific gravity  Results provide  Preliminary information  Correlation with other chemical and microscopic results 4 2  6/20/2024 INTRODUCTION (CONTINUED)  Provides preliminary information concerning disorders such as  Glomerular bleeding  Liver disease  Inborn errors of metabolism  Urinary tract infection  Renal tubular function 5 COLOR  Ranges from colorless to black  Normal variations caused by  Normal metabolic functions  Physical activity  Ingested materials  Pathologic conditions 6 3  6/20/2024 NORMAL URINE COLOR  Common terminology  Pale yellow, yellow, dark yellow  Should be consistent within laboratory  CTC lab – colorless/yellow/dark yellow/brown/red/other  Urochrome is pigment causing yellow color  Normally excreted at a constant rate  Increased in thyroid disorders and fasting  Increases when specimen sits at room temperature  Provides estimate of body hydration  Pale yellow to dark yellow can be normal  Dilute urine is pale and concentrated urine is dark yellow 7 NORMAL URINE COLOR (CONTINUED)  Additional pigments uroerythrin, urobilin  Color changes in older specimens  Uroerythrin  Pink pigment  Attaches to amorphous urates formed in refrigerated specimens  Urobilin  Oxidation of normal constituent, urobilinogen  Orange-brown color in older specimens 8 4  6/20/2024 ABNORMAL URINE COLOR  Many colors and causes  Often reason patient comes to the physician  Common abnormal colors  Dark yellow/amber/orange  Red/pink/brown  Brown/black  Blue/green 9 DARK YELLOW/AMBER/ORANGE  Dark yellow and amber  Normal = concentrated urine  Abnormal = bilirubin  Foam  Bilirubin produces yellow foam when shaken  Normal urine produces small amount of white foam caused by protein  Bilirubin indicates possible hepatitis virus present  Standard precautions 10 5  6/20/2024 DARK YELLOW/AMBER/ORANGE (CONTINUED_1)  Photooxidation of large amounts of urobilinogen produces yellow-orange urine  No yellow foam when shaken  Photooxidation of bilirubin to biliverdin produces yellow-green urine  Phenazopyridine (pyridium) or Azo-Gantrisin for urinary tract infection produces thick orange pigment and yellow foam (no bilirubin)  Thick pigment is noticeable, obscures natural color, and interferes with reagent strips  Azuflidine, some laxatives, and certain chemotherapy drugs can cause an orange-colored urine 11 RED/PINK/BROWN  Blood is a common cause of red urine  Color can range from pink to brown  Pink = small amount of blood  Brown = oxidation of hemoglobin to methemoglobin  Methemoglobin  RBCs remaining in acid urine  Fresh brown specimen can indicate glomerular bleeding 12 6  6/20/2024 RED/PINK/BROWN (CONTINUED_1)  Cloudy red urine = RBCs  Clear red urine = hemoglobin/myoglobin  Hemoglobin  In vivo lysis of RBCs  Patient’s plasma will also be red  Consider in vitro lysis  Myoglobin  Breakdown of skeletal muscle  Fresh urine is often more reddish/brown  Patient’s plasma is clear 13 RED/PINK/BROWN (CONTINUED_2)  Port wine–colored urine  Oxidation of porphobilinogen to porphyrias  Nonpathogenic red urine  Menstrual contamination  Pigmented foods  Medications (rifampin, pheno-compounds)  Fresh beets  Genetically susceptible people in alkaline urine  Black raspberries in acid urine 14 7  6/20/2024 BROWN/BLACK  Additional testing for specimens that  Turn black after standing at room temperature  Test negative for blood  Melanin  Excess in malignant melanoma  Oxidation of melanogen to melanin  Homogentisic acid  Black color in alkaline urine  Alkaptonuria  Medications, levodopa, methyldopa, phenol derivatives, flagyl and furadantin 15 BLUE/GREEN  Urinary and intestinal bacterial infections are the pathogenic cause  Urinary: pseudomonas infection  Intestinal: infection causing increased urinary indican oxidizing to indigo blue  Clorets (green); B vitamins and asparagus (green); medications, Robaxin, Indocin, Tivorbex, Elavil and Diprivan (blue)  Catheter bags: purple color from Klebsiella, and Providencia  IV phenol medications cause green 16 8  6/20/2024 CLARITY  Refers to the transparency or turbidity of a specimen  Visual examination  Gently swirl specimen in a clear container in front of a good light source  Specimen should be in a clear container  Color and clarity are routinely done at the same time  Terminology used to report  Clear, slightly cloudy (hazy), cloudy, turbid, milky 17 URINE CLARITY  Clear: No visible particulates, transparent  Slightly Cloudy/Hazy: Few particulates, print easily seen through urine  Cloudy: Many particulates, print blurred through urine  Turbid: Print cannot be seen through urine  Milky: May precipitate or be clotted 18 9  6/20/2024 NORMAL CLARITY  Freshly voided urine is usually clear, particularly if it is a midstream specimen  Amorphous phosphates and carbonates may cause a white cloudiness in an alkaline urine specimen 19 NON-PATHOGENIC TURBIDITY PATHOGENIC TURBIDITY  Hazy female specimens with squamous epithelial  Most common: RBCs, WBCs, bacteria cells and mucus  Also: nonsquamous epithelial cells, yeast,  Bacterial growth in non-preserved specimens trichomonads, abnormal crystals, lymph fluid, lipids  Refrigerated specimens with precipitated  The extent of turbidity should correspond to amorphous phosphates (white), carbonates (white), and urates (pink) the amount of material observed in the microscopic examination  Contamination: fecal, talc, semen, vaginal creams, IV  Clarity is one of the criteria considered in contrast media determining the necessity of performing a microscopic examination 20 10  6/20/2024 SPECIFIC GRAVITY (SG)  Evaluation of urine concentration  Isosthenuric: SG of 1.010 (the SG of the plasma ultrafiltrate)  Determines if specimen is concentrated enough to provide reliable chemistry results  Hyposthenuric: SG lower than 1.010  Definition: the density of a solution compared with  Hypersthenuric: SG higher than 1.010 the density of an equal volume of distilled water at  Normal random specimen range the same temperature  1.002 to 1.035; most common 1.015 to 1.025  Below 1.002 may not be urine  Consistent low readings: further testing 21 REFRACTOMETER  Measures velocity of light in air versus velocity of light in a solution  Concentration changes the velocity and angle at which the light passes through the solution  Prism in the refractometer determines the angle that light is passing through the urine and converts angle to calibrated viewing scale  Advantages  Temperature compensation not needed  Light passes through temperature-compensating liquid  Compensated between 15°C and 38°C  Small specimen size: one drop 22 11  6/20/2024 REFRACTOMETER (CONTINUED_2) 23 REFRACTOMETER (CONTINUED_3)  Drop of urine placed on prism  Focus on light source, and read scale  Wipe off prism between specimens  Calibration  Distilled water should read 1.000; adjust set screw if necessary  5% NaCl should read 1.022 ± 0.001  9% sucrose should read 1.034 ± 0.001 24 12  6/20/2024 URINOMETRY  Urinometer consists of a weighted float attached to a scale that has been calibrated in terms of urine specific gravity  Weighted float displaces a volume of liquid equal to its weight and has been designed to sink to a level of 1.000 in distilled water  Less accurate and is not recommended by CLSI  A specimen containing 1 g/dL protein and 1 g/dL glucose has a specific gravity reading of 1.030  Calculate the corrected reading 1.030 – 0.003 (protein) = 1.027 – 0.004 (glucose) = 1.023 corrected specific gravity 25 URINOMETRY (CONTINUED_2)  Abnormally high results = >1.040  Radiographic contrast media (IVP)  Dextran, other IV plasma expanders  Check patient’s clinical course/history  Reagent strip readings and osmometry not affected by high-molecular-weight substances  Should be used as an alternative if possible 26 13  6/20/2024 OSMOLALITY  A more representative measure of renal concentrating ability can be obtained  Specific gravity depends on the number of particles present in a solution and the density of these particles  Osmolality is affected only by the number of particles present  Substances of interest are small molecules  Sodium  Chloride  Urea  1 g molecular weight of a substance divided by the number of particles into which it dissociates (= to MW of substance)  Glu = 180 g/osm (C + H + O)  NaCl = 58.5 g/osm (Na + Cl)  The unit of measure used in the clinical laboratory is the milliosmole (mOsm) 27 OSMOLALITY (CONTINUED)  Osmolality of a solution can be determined by measuring a property that is mathematically related to the number of particles in the solution  Colligative property  Changes in colligative properties  Lower freezing point  Higher boiling point  Increased osmotic pressure  Lower vapor pressure  Measuring osmolality in the urinalysis laboratory requires an osmometer  Additional step in the routine urinalysis procedure  Automated osmometer utilizes freezing point depression to measure osmolality 28 14  6/20/2024 HARMONIC OSCILLATION DENSITOMETRY  Based on the principle that the frequency of a sound wave entering a solution changes in proportion to the density of the solution  Was used in early automated urinalysis instruments  Addition of reagent strip for specific gravity has been replaced in the automated system 29 REAGENT STRIP SPECIFIC GRAVITY  The reagent strip reaction is based on the change in pKa (dissociation constant) of a polyelectrolyte in an alkaline medium  Releasing H ions in direct proportion to the number of ions in the solution  The more hydrogen ions released, the lower is the pH  Indicator bromothymol-LS blue on the reagent pad measures the change in pH  Indicator changes from blue (1.000 [alkaline]), through shades of green, to yellow (1.030 [acid])  Not affected by nonionizing substances 30 15  6/20/2024 ODOR  Not routinely reported  Fresh urine: faintly aromatic  Older urine: ammonia  Metabolic disorders: maple syrup urine disease, ketosis (fruity), infection (ammonia/unpleasant)  Food: garlic, onions, asparagus (genetic: only certain people can smell asparagus, but all produce odor) Table 5-5 Possible Outcomes of Urine Odor1 Odor Cause Aromatic Normal Foul, ammonia-like Bacterial decomposition, urinary tract infection Fruity, sweet Ketones (diabetes mellitus, starvation, vomiting) Maple syrup Maple syrup urine disease Mousy Phenylketonuria Rancid Tyrosinemia Sweaty feet Isovaleric acidemia Cabbage Methionine malabsorption Bleach Contamination 31 POSTAMBLE  READ the TEXTBOOK for the details to answer the UNIT OBJECTIVES.  USE THE UNIT OBJECTIVES AS A STUDY GUIDE  All test questions come from detailed material found in the TEXTBOOK (Not this PowerPoint) and relate back to the Unit Objectives 32 16