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Exam of Urine
Chemical Examination of Urine, Chpt 5
Question | Answer |
---|---|
What do the urinary dip stick test for? | pH, blood, leukocyte esterase, nitrite, protein, glucose, ketones, blood, bilirubin, urobilinogen, and specific gravity. |
How are improper results obtained on the reagent strips? | Unmixed specimen, allowing the strip to remain in urine for excess amount of time, and excess urine on pads of reagent strips. |
When should you perform a quality control of reagent strips? | every 24 hrs for open bottles, new bottle of reagent strips, questionable results, or there is a concern about the integrity of the strips. |
Why can't you use distilled water to test a negative control? | because the reagent strips are designed to perform at ionic concentrations similar to urine. |
What is the orange pigment present in urine that is caused by the patient? | Phenazopyridine ompounds that are found in the urine of patients taking certain medicines. |
What organ(s) are the major regulators of the acid-base content in the body? | Lungs and kidneys |
How is the acid-base content maintained? | By secretion of hydrogen in the form of ammonium ions, hydrogen phosphate, and weak organic acids, and by the reabsorption of bicarbonate form the filtrate in the convoluted tubules. |
What is the pH of the first morning specimen? | slighly acidic 5.0 to 6.0 |
Is the urine acidic or alkaline after meals. | more alkaline |
What is the range of pH from random samples? | 4.5 to 8.0 |
What is the pH influenced by, or what other patient information must be considered in conjunction with? | Diet, medication, acid-base content of blood, renal function, presence of urinary tract infection, age of specimen. |
What is the importance of urinary pH? | Primarily as an aid in determining the existence of systemic acid-base disorders of metabolic or respiratory origin and in the management of urinary conditions that require the urine to be maintained at a specific pH. |
Is the urine acidic or alkaline if there is a respiratory or metabolic acidosis/ketosis present but not related to renal function disorder. | acidic |
Is the urine acidic or alkaline if there is a respiratory or metabolic alkalosis present? | alkaline |
If the urine doesn't conform to this pattern, what does it mean? | May be used to rule out the suspected condition or may indicate a disorder resulting from the kidneys' inability to secrete or to reabsorb acid or base. |
What do the precipitation of inorganic chemicals dissolve in the urine form and how does it relate to pH? | Urinary crystals and renal calculi; and precipitation depends on urinary pH. |
How does controlling the urine pH help control crystals and stones? | By making it incompatible with the precipitation of the particular chemicals causing the calculi formation. |
What is the primarily pH of a person on a high-protein and high-meat diet? | acidic |
What is the primarily pH of a vegetarian? | alkaline |
What does it mean if a freshly excreted urine produces a pH of 9. | A pH of 9 means that it is a improperly preserved specimen. No normal or abnormal condition would produce a 9 pH. |
What are some of the causes of acidic urine? | Emphysema, diabetes mellitus, starvation, dehydration, diarrhea, presense of acid-producing bacteria, high-protein diet, cranberry juice and some medications. |
What are some of the causes of alkaline urine? | Hyperventilation, vomiting, renal tubular acidosis, presence of urease-producing bacteria, vegetarian diet, and old specimens. |
What are the clinical significance of urine pH? | Respiratory/metabolic acidosis/ketones, respiratory/metabolic alkalosis, defects in renal tubular secretion & reabsorption of acids and bases-renal tube acidosis,stone formation, treatment of uti, precipitation/id of crystals, determines bad specimens. |
What does increased pH cause? | It causes false positive protein results. |
How is pH measured and what is the range? | It is measured in 0.5 to 1-unit increments b/w 5 and 9. |
What is the double-indicator system? | It is what is use to measure the wide range of pH and its measured by using methyl red and bromthymol blue. |
What is the pH range for methyl red and what does it change to? | It produces a color change from red to yellow in the pH range of 4.4 to 6.2. |
What is the pH range for bromthymol blue and what does it change to? | It turns to yellow to blue in the range of 6.0 to 7.6. |
What is the combined color change for a double-indicator system, explain? | In the pH range 5 to 9 measured by reagent strips, one sees colors progressing from orange at pH 5 through yellow and green to a final deep blue at pH 9. Methyl red + H^+ --> Bromthymol blue - H^+(Red-Orange-->Yellow) (Green-->Blue) |
Even though there are no known substances that interfere with urinary pH measurements, what could happen to cause a alkaline urine to falsely read acidic? | Runover from a highly acidic protein pad. |