Urinalysis Exam Latest Upated Questions With Completed & Verified Solutions

Urinalysis Exam Latest Upated Questions With Completed & Verified Solutions What time frame can we run a urinalysis within? - Answer- fresh urine should be evaluated within 2-4 hours of collection for the most valid results. Ms. D says that we need to run it within the first 30 minutes... What can we evaluate with the urinalysis? - Answer- renal function values protein concentrations metabolic functions What is a "complete urinalysis"? - Answer- the evaluation of the physical (color, clarity and specific gravity), chemical, and formed element characteristics of urine What are the two preferred methods for urine collection? - Answer- cystocentesis catheterization What are the two less useful methods of urine collection? - Answer- free-catch bladder expression What should we keep in mind if the only way to get a sample is to do a free catch? - Answer- midstream to decrease contamination What kind of abnormalities do we need a NON free catch for? - Answer- We need to obtain cysto or catheterized samples for problems related to disease in the kidneys or urinary bladder What are some problems with bladder expression? - Answer- possibility of rupturing the bladder if excessive pressure is used or if the bladder wall is compromised. When should we get a urinalysis ideally? - Answer- A first morning sample will provide the best evaluation concentrating ability What is the best time to get a u/a to evaluate urine for casts? - Answer- first stream of the morning Why do we do the u/a ASAP after collecting the sample? - Answer- because cellular element and crystals can deteriorate, making it difficult to recognize them correctly. Plus, crystals can dissolve over time. How long can we postpone running a urinalysis? - Answer- a sample can be refrigerated for 6 hours - NO LONGER. What do we have to remember about a sample if it has been refrigerated? - Answer- Sample needs to return to room temperature before running any tests on it. What chemical parameters do we worry about with refrigerated samples? - Answer- Several indicator pads on reagent strips are enzyme-based runs, and the speed of rxn decreases as the temperature decreased - therefore causing false-negatives/positives There should be a urinalysis record-keeping systems which includes::: - Answer- when the sample was obtained how the sample was obtained any medication giver prior to the u/a when the u/a was performed patient name owner and hospital ID number Do we need to run controls for a u/a? - Answer- If the reagent strips are handled and stored properly, and not used past their expiration date, controls do NOT need to be performed What are the common sources for error in urinalysis? - Answer- Errors are primarily pre-analytical (due to inappropriate collection) and analytical What is the most common pre-analytical error? - Answer- contamination of urine during sample collection What should we know about cleaning products and urine samples? - Answer- cleaning products/solvents can alter the chemical rxns on a reagent strip. -- wouldnt be able to do a strip on off-the-table sample What are the common analytical errors? - Answer- 1) Delay in performing u/a w/o refrigeration 2) Failure to mix sample prior to aliquoting 3) Failure to resuspend the sample 4) Failure to follow SOPs How long do we centrifuge a urine sample for? - Answer- we centrifuge 5-10 mLs of urine for 3-5 minutes at rpms What are the parts of a spun down urine sample? - Answer- supernatant pellet What color is normal urine? - Answer- clear and light to dark yellow What factors can alter the color of urine? - Answer- diet, disease and drugs Bluish urine - Answer- caused by methylene blue being used as an acidifier. Black or brown urine - Answer- methemoglobin and nitrites green urine - Answer- seen when bilirubin is present and allowed to break down over time red, red-brown, orange urine - Answer- relate to the presence of erythrocytes or heme pigments in the urine hematuria - Answer- indicated when the urine is red and turbid (ie. cloudy) What if urine is red and translucent? - Answer- hemoglobinuria myobloinuric What instrument do we use for SG? - Answer- refractometer What is the specific gravity of distilled water? - Answer- 1.000 Is there a reference range for the normal patient's specific gravity? - Answer- NOPE What is the expected USG on a patient that is dehydrated but has normal renal function? - Answer- canine USG >1.030 feline USG > 1.035 What part of the urine do we perform chemical analysis on? - Answer- supernatant of centrifuged or non-centrifuged urine is okay too Why would we want to do perform analysis on uncentrifuged urine? - Answer- b/c centrifugation clears the blood cells from the urine and may cause false negatives on the blood reagent pad What is the advantage to performing a u/a on a centrifuged urine sample? - Answer- to clear the urine of particulate that may interfere with interpretation of the reagent pad changes. Glucose reagent pad::: - Answer- -enzyme dependent=temperature sensitive -ascorbic acid will cause a false negative -decreased activity if USG <1.005 -cleaning agent causes false positive -watch expiration date Ketone reagent pad::: - Answer- -only detects one of the ketoacids possible -Neg results don't always mean negative - highly sensitive to light, heat and moisture -false positives seen with captopril, D-penicillinamine, tiopronin, and cystine Conjugated Bilirubin reagent pad::: - Answer- conjugated bilirubin is bilirubin excreted in the urine. -dark colored urine will make bilirubin rxn difficult to interpret -ascorbic acid can result in a false negative Blood on reagent pad::: - Answer- the test pad for blood will react with erythrocytes, hemoglobin and myoglobin - sometimes RBCs cause stippend look - causing there to be a difference in look of erythrocytes & hemoglobin/myoglobin Protein on reagent pad::: - Answer- detects albumin highly alkaline urine can cause false + Always compare to USG 1+ protein with 1.010 SG = more significant than: 1+ urine protein with 1.040 SG Non-useful reagent pads - Answer- specific gravity, nitrate and leukocyte reaction strips = invalid in veterinary patient (plus, some Sulfa drugs will cause false positives)