the most common method for chemical testing

high amounts that can interfere and cause false positives

factors that reagent strips should be protected against

specific gravity of urine will always be 1.010; implies end stage renal disease; tubules of nephron are unable to function properly

normal specific gravity

measures ionic solutes Na K Cl NH4

impregnated into reagent strip pad at alkaline pH that allows for the color change when protons are released decreasing pH

indicator of color change

normal pH of urine

double indicators of pH test pad

pH orange

pH green

pH blue

not physiologically possible pH

pH urine turns blue green to?

three most common reasons for a urine pH to be above 8.0

normally very small amounts in urine

normal amount of protein in urine

first sign of kidney disease

the protein usually present at increased concentration; strip test most sensitive

overflow proteinuria; too much protein in plasma and passes into urine; septicemia, hemoglobinuria, and myoglobinuria, MM BJ proteins

glomerular and tubular proteinuria; GFB is defective allowing proteins in plasma to enter ultra filtrate; tubular reabsorption function is altered or impaired

develops from inflammatory process in the urinary tract

most serious and damaging type of glomerular proteinuria, renal

proximal tubular dysfunction; renal proteinuria

detects all proteins in urine albumin and globulins; historical

protein error in indicators; buffers hole pH constant indicator dyes release H ions due to proteins present; H and proteins create color change; blue green

can produce false positive proteins

red blood cells in urine; smoky, cloudy urine clarity

free hemoglobin in urine; clear urine clarity

intracellular protein of muscle that will e increased in the bloodstream when muscle tissue is damaged by trauma or disease and will pass through glomerular filtration barrier; detected in reagent strip; also caused by alcohol OD, toxins (cocaine or heroin) and certain metabolic disorders

red or brown urine; plasma shows hemolysis

pink, red or brown urine; plasma appears normal

historical method to differentiate hemoglobinuria from myoglobinuria

pad contains chromogen and peroxide to detect blood; heme reduces peroxide, chromogen is oxidized, causing color change from yellow to green

interferes with hydrogen peroxide in blood and glucose, bilirubin, and nitrites reactions causing false negative suggested by microscopic findings but negative reagent strip result

normally few WBCs seen

a leukocyte indication of pathologic process (inflammation) from kidney (pyelonephritis) to urinary tract (urethritis)

azurophilic granules of leukocytes to cleave an ester in pad; cleavage forms and couples with diazonium salt; end result is azo dye and color change from beige to violet

not detected in leukocyte esterase strip pad

amount detected in leukocyte esterase

formed from nitrate reducing bacteria

forms diazonium salt which couples with compound in pad to produce azo dye; color change white to pink

presence of glucose in urine

presence of non-glucose sugars (fructose sucrose lactose) or combination in urine

not normally seen in normal urine

most common disease that causes hyperglycemia and glucosuria

renal threshold for plasma glucose

most significant sugar other than glucose signifying inability to metabolize it into glucose (GALT seen in infants)

double sequential; oxidizes glucose to form hydrogen peroxide and gluconic acid; peroxidase oxidizes chromogen in pad resulting in color change; specific for glucose

used to identify reducing sugars; most common is Clinitest (tablet test); strip negative for glucose, Clintest positive, sugars present other than glucose

breakdown products from large amounts of fatty acids

principal form detected by reagent strip method

not detected by strip tests

caused when blood ketone level exceeds 70 mg/dL; breath fruity; caused by starvation, bulimia, strenuous exercise, diabetes mellitus, or alcoholism

renal threshold for ketones

used to detect ketones; color change from beige to purple; positives always confirmed with Acetest

tablet test used to correctly identify ketones if truly present

seen in hepatic or post hepatic jaundice

only direct conjugated bilirubin detected since indirect is not water soluble and stays bound to albumin; bilirubin reacts with diazonium salt in pad to form azobilirubin which is brown

tablet test for confirmation of bilirubin in urine; detects even lower amounts than strip test; azo coupling of bilirubin with diazonium salt

normally present in low amounts

multistix

use azocoupling reaction specific for urobilinogen