Urinalysis EXAM COMPLETE QUESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+

Urinalysis EXAM COMPLETE QUESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+ First morning specimen - Answer- Most concentrated, most acidic Formed elements more stable Random specimen - Answer- Used for most routine urinalysis Timed specimen - Answer- Usually for 24 hours Measures things with circadian variation such as hormones, creatinine clearance, GFR Routine void technique - Answer- Acceptable for routine urinalysis Midstream technique - Answer- Ideal, best used for urine culture Reduces possibility of contamination Pediatric technique - Answer- Use plastic collection bags with skin adhesive Check every 15 minutes Many possible sources of contamination Suprapubic aspiration - Answer- For bug cultures, especially anaerobes Also for infants when contamination not an option Routine Collection container - Answer- Clear plastic, disposable, leak-proof, 50-100 mL Midstream Collection container - Answer- Disposable, sterile, individually packaged 24-hour Collection container - Answer- Brown-opaque plastic, 3000 mL with preservatives (i.e. HCl) Random specimen preservation - Answer- Fridge up to 24 hours Do not fridge if testing within 2 hours (amorphous crystals will precipitate) 24-hour specimen preservation - Answer- Fridge throughout collection period If preservatives added, no good for routine analysis Sediment preservative for urine - Answer- Formalin Effect on urine clarity if left out - Answer- Becomes more turbid as bugs proliferate Effect on urine pH if left out - Answer- Increases as bugs decompose urea to ammonia Effect on urine glucose if left out - Answer- Decreases as cells and bugs use it up Effect on urine ketones if left out - Answer- Decreases as bugs destroy acetoacetic acid and/or volatilize acetone Effect on urine bilirubin if left out - Answer- Decreases due to oxidation to bilverdin and/or hydrolysis of unconjugated form Effect on urine urobilinogen if left out - Answer- Decreases due to oxidation to urobilin Effect on urine nitrite if left out - Answer- Variable. Bugs will produce it, but it can also be converted to N2 gas Effect on urine RBCs/WBCs if left out - Answer- Decreased due to disintergration, especially if the sample is alkaline Criteria for urine specimen rejection - Answer- NSQ, inappropriate specimen type, visibly contaminated, incorrect preservative, leaky container, requisition incomplete Technique for microscopic urine examination - Answer- Volume: 12 mL Centrifugation speed and time: 400 RCF for 5 minutes [conc] of sediment: 12 to 1 Cloudy urine - Answer- Precipitation of crystal (amorphous urates) in the fridge Turbidity in fresh urine - Answer- Could be RBCs, WBCs, bugs, fat, mucous or many epithelial cells Red urine - Answer- Blood, hemoglobin, myoglobin, beets Dark amber urine - Answer- Presence of bilirubin Urine SG/Osmolality - Answer- Indicates urine concentration Normal SG: 1.003 - 1.030 Normal osmo: 100-1100 mOsm/kg Low urine SG/Osmo - Answer- Dilute urine, increased fluid intake, diabetes insipidus, diuretics, low ADH If as low as 1.000...suspect tampering/toilet water High urine SG/Osmo - Answer- Concentrated urine, dehydration, proteinuria, radiographic dye (could be as high as 1.050!) Method of measuring urine SG/Osmo - Answer- Dipstick or refractometer (Check periodically with dilute H20, should read 1.000) Urine volume (24 hour) - Answer- Normal: ~1.5 L/day Polyuria - Answer- Increased volume, >2 L/day Increased fluid intake, diabetes insipidus, diabetes mellitus, renal tubular damage Oliguria - Answer- Decreased volume, <600 mL/day Dehydration, shock, obstruction of urinary tract Anuria - Answer- No urination Acute renal failure Dipsticks - Answer- Store at RT in tightly capped container QC daily and whenever a new bottle is opened pH of urine - Answer- Normal: 5-8 (on a random specimen) Protein diet = tends to be more acidic Vegetarian diet = tends to be more alkaline Urine pH >8 - Answer- Specimen has been improperly stored, bugs have produced urease Acidic urine - Answer- Respiratory or metabolic acidosis Some bacterial infections, such as E.coli Alkaline urine - Answer- Respiratory or metabolic alkalosis Infections caused by urease-making bugs, such as Proteus Dipstick indicator for pH - Answer- Dual indicator system; methyl red and bromthymol blue Glucose of urine - Answer- Normal = Negative - (should be 100% reabsorbed) Glycosuria - Answer- Renal threshold for glucose exceeded (>10 mmol/L) Can also occur if threshold lowered by defective re-absorption Dipstick reaction for glucose - Answer- Reaction with glucose oxidase and peroxidase. End result; oxidation of a chromogen = color change Specific False negatives (-) for dipstick glucose - Answer- Ascorbic acid, improper storage resulting in bugs using it up False positives (+) for dipstick glucose - Answer- Contaminating oxidant such bleach