Urinalysis Gross examination

KEY TERMS CHAPTER 4 CLARITY HARMOBNIC OSCILLATION DENSITOMETRY HYPERSTHENURIC HYPOSTHENURIC ISOSTHENURIC REFRACTOMETRY SPECIFIC GRAVITY URINOMETRY

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

Color of Urine Urochrome is the primary pigment responsible for the normal color Color of urine gives the estimate of concentration 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

Dark Yellow/Amber/Orange Foam Yellow - bilirubin is responsible White – protein is responsible Red Color contribution Amount of blood pH Length of contact

Color of Urine Green/ Blue- Green Pink/Red (Fig 4.1) 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 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.

Specific Gravity Harmonic Oscillation Densitometry Reagent Strip 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

Clinical Correlations 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

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