PART 1: routine examination of urine (week 4) Flashcards
(49 cards)
plastic strips that contain one or more chemically impregnated test sites on an absorbent pad. Each absorbent pads contain one or more reagents and these
reagents react with the urine, producing a distinct color. The color produced will be compared to the comparator block
Reagent Strips (dip stick)
1) Mix the urine
2) Insert reagent strip
3) Remove excess urine
4) Time according to manufacturer’s directions.
5) Compare test areas closely with corresponding color
charts.
6) Hold strip horizontally and close to the color chart.
Reagent Strips (dip stick) PROCEDURE
- With desiccant (used to absorb moisture) in opaque (black container bottle), tightly capped containers. Most common reason for the discoloration of the strip
is the uncapped containers - Room temperature (below 30°C)
- Keep strips in their original container
DO STORAGE AND GENERAL PRECAUTION
- Expose the strips to volatile fumes
- Touch the test areas
- Use if the chemical pads become discolored
- Use past the expiration date
- Also: Do not transfer test strips to another vial, prolong the dipping of the test (1 second is all it takes), and touch the test zones with you fingers
DON’T STORAGE AND GENERAL PRECAUTION
Sources of erros
- Unmixed specimen
- Strip in urine for extended period
- Excess urine in the strip (run over bet chemicals)
- Refrigerated specimen
If the urine specimen will not be mixed, the formed elements such as RBCs and WBCs will just settle at the bottom and will not be detected
Unmixed specimen
Leaching of reagents from the pad.
*Leaching - lalabas
Strip in urine
for extended
period
Distortion of colors
What to do to prevent run-over of chemicals?
Blot the edge of the strip and hold the strip
horizontally
Excess urine
in the strip
(run-over bet
chemicals)
- False negative enzymatic tests. For example, glucose which has an enzyme called glucose oxidase that doesn’t react in cold temperatures.
- To avoid this, allow the specimen to reach room temperature before dipping the strip
Refrigerated
specimen
Tested with known positive or negative controls.
QUALITY CONTROL
1) Test using different reagents or methodologies to detect the
same substances as detected by the reagent strips
2) Same or greater sensitivity or specificity
3) Tablets and liquid chemicals
CONFIRMATORY TEST
- It reflects the ability of the kidney to maintain normal hydrogen ion concentration in plasma and extracellular
fluid. - The organs that play a role in acid
base balance are the kidneys and the lungs
REACTION/ pH
‒ To maintain acid-base balance in the body; kidneys secrete hyrogen ions and bicarbonate should be reabsorbed
‒ Blood must buffer and eliminate excess acids
‒ Buffering capacity of blood depends on bicarbonate ions (HCO3- )
‒ Secretion of hydrogen ions causes reabsorption of
bicarbonates
pH
i. Secretion of H+ in the form of NH4+, hydrogen
phosphate & weak organic acids
ii. Reabsorption of bicarbonate from the filtrate in the
PCT.
Maintenance of acid-base balance in the body via the kidneys is made possible through
Respiratory or metabolic
acidosis
Respiratory or metabolic
alkalosis
Defects in renal tubular secretion and re-absorption of acids and bases
Renal tubular acidosis
Determination of unsatisfactory specimen. An unsatisfactory pH is when the specimen reaches a
pH of 9 or a pH of 4
- Increased protein and meat diet
- Cranberries
- Acid producing bacteria
- Starvation
- Dehydration
- Diarrhea
- Diabetes mellitus
Acid urine
- Increased fruits and vegetables
- Citrus
- Less acidic after meal (alkaline tide)
- Renal tubular acidosis
- Urease producing bacteria
- Hyperventilation
- Old specimen
Alkaline urine
methyl red changes
color from red to yellow
pH range of 4 to 6
bromthymol blue changes color from yellow to blue in the
pH range of 6 to 9
The pH range measured by the reagent strips
5 to 9
The color changes from orange to yellow, green
At pH 5
