200 likes | 723 Views
Urinalysis Chapter 4. Kaur, 2006. CLARITY HARMOBNIC OSCILLATION DENSITOMETRY HYPERSTHENURIC HYPOSTHENURIC. ISOSTHENURIC REFRACTOMETRY SPECIFIC GRAVITY URINOMETRY. KEY TERMS CHAPTER 4. Physical Examination of Urine.
E N D
UrinalysisChapter 4 Kaur, 2006
CLARITY HARMOBNIC OSCILLATION DENSITOMETRY HYPERSTHENURIC HYPOSTHENURIC ISOSTHENURIC REFRACTOMETRY SPECIFIC GRAVITY URINOMETRY KEY TERMS CHAPTER 4
Physical Examination of Urine • Physical examination of urine includes determination of color, clarity, and specific gravity • Provides preliminary information • Measurement of SG aids in evaluation of renal tubular function • Confirms or can explain findings in chemical and microscopic evaluation
Colorless Recent fluid consumption Pale yellow Polyuria Diabetes insipidus Diabetes mellitus Dark yellow Concentrated Amber/Orange Bilirubin Acriflavine Pyridium Nitrofurantion Phenindione Yellow-green/brown Bilirubin oxidized to biliverdin Color of Urine Urochrome is the primary pigment responsible for the normal color Color of urine gives the estimate of concentration
Dark Yellow/Amber/Orange • Foam • Yellow - bilirubin is responsible • White – protein is responsible • Red Color contribution • Amount of blood • pH • Length of contact
Green/ Blue- Green Pseudomonas infection Amitriptyline Robaxin Clorets Indican Methylene blue Phenol Pink/Red (Fig 4.1) RBC’s Hgb Myoglobin Porphyrins Beets Rifamin Menses Color of Urine
Color of Urine • Brown/Black • RBC’s oxidized to methmoglobin • Homogentistic acid • Melanin • Phenol derivatives • Argyrol • Levodopa • Flagyl
Clarity (Table 4-2, p.36) • Term that refers to transparency/turbity • Determined by visual inspection • Color and clarity determined at the same time • Terminology should be consistent within lab
Clarity (Table 4-2, p36) • Normal • Clear • Precipitation of amorphous phosphates and carbonates may cause white cloudiness
Nonpathologic Turbidity • Squamous epithelial cells • Mucus • Specimens allowed to stand or refrigerated • Semen • Fecal contamination • Radiographic contrast media • Talcum powder • Vaginal creams • Pedi-diaper creams
Pathologic Turbidity • Rbcs' • WBC's • Bacteria • Nonsquamous epithelial cells • Yeast • Abnormal crystals • Lymph fluid • Lipids
Laboratory Correlations with Turbidity Table 4-5, p. 37 Example questions: • How would a specimen containing intact red blood cells differ from one that has hemoglobin? • Addition of dilute acetic acid to a cloudy urine specimen dissolves _______ • Slight warming of turbid specimen may dissolve _________
Specific Gravity • Defined as the density of a solution compared to density of similar volume of distilled water at a similar temperature • Kidneys ability to selectively reabsorb essential chemicals and water from the glomerular filtrate is one of the most important body functions; • SG detects dehydration, abnormalities in ADH, influenced by urea molecules, sodium, chloride, glucose, dissolved solids, cells present
Specific Gravity • Measure of the density of the dissolved chemicals • Influenced by number of particles and size • Larger particles contribute more
Urinometery • Consists of a weight float attached to a scale that has been calibrated in terms or urine specific gravity. • Weighted float displaces volume of liquid • Considered less accurate than other methods • Not recommended by NCCLS
Refractometery • Determines concentration of dissolved particles in specimen by measuring refractive index. • Refractive index is a comparison of the velocity of light in air with velocity of light in solution. • Concentration of dissolved particles present in a solution determines the velocity and angle at which light passes through a solution.
Refractometery • Concentration of specimen determines angle at which light beam enters prism. Specific gravity scale is calibrated in terms of angles at which light passes through specimen. • Small amount is needed and temperature corrections not necessary.
Harmonic Oscillation Densitometry Based on the principle that frequency of a sound wave entering a solution will change in proportion to the density of solution Reagent Strip SG measured by chemical reaction producing a color reaction Specific Gravity
Isothenuric SG of 1.010 Plasma filtrate entering glomerulus Hyposthenuric Below SG 1.010 Hypersthenuric Above SG 1.010 Normal random specimens may range between 1.003 to 1.035 Most random specimens range 1.015 to 1.025 Clinical Correlations
Odor • Seldom has clinical significance • Faint aromatic odor • Breakdown of urea responsible for ammonia odor • Unusual odors results of bacterial infections, diabetic ketones, serious metabolic disorders, certain food ingestion