Summative Exam Review Questions #07

MEDICAL LABORATORY SCIENCE 9. SUMMATIVE EXAM REVIEW QUESTIONS #07 + ANSWERS & RATIONALIZATIONS 1. 2. 3. 4. 5. 6. 7. 8. Exchange transfusions are used primarily to: a. Provide antigen negative RBCs b. Remove antibody c. Remove antibody coated RBCs d. Remove high levels of unconjugated bilirubin and thus prevent kernicterus All of the following are routinely performed on a cord blood sample EXCEPT: a. Forward ABO typing b. Antibody screen c. Rh typing d. DAT All of the following are reasons for a positive DAT on cord blood cells of a newborn EXCEPT: a. High concentrations of Wharton’s jelly on cord cells b. Immune anti-A from an O mother on the cells of an A baby c. Immune anti-D from an Rh negative mother on the cells of an Rh-positive baby d. Immune anti-K from an K-negative mother on the cells of a K-negative baby Infants do not require crossmatching during: a. The first 4 months b. The first 6 months c. The first year d. An indefinite period if a parent’s blood is used Preliminary blood bank testing for neonates <4 months of age must include: a. ABO forward typing and ABO reverse typing b. ABO reverse typing and testing for K antigen c. ABO reverse typing and antibody detection testing d. ABO forward typing and Rh testing for D antigen Recommended speed of the serofuge for agglutination grading: a. 500 g b. 800 g c. 1,000 g d. 2,000 g → Serological Centrifuge (Serofuge) ▪ In blood banking, centrifuges may be run at speeds between 3400 and 3500 RPM when they are used for red cell washing and for grading ▪ 1,000g is the force that is recommended for agglutination grading. Heavy spin centrifugation: a. 2, 000 x g for 2 to 3 minutes b. 5, 000 x g for 5 minutes c. 10,000 x g for 5 minutes d. 15,000 x g for 10 minutes → Heavy vs Light Spin 10. 11. 12. 13. 14. One of the best ways to protect employees and keep a safe laboratory environment is to provide employees with: a. Health insurance b. Safety education c. Rest breaks d. Fluid-repellent laboratory coats What is the purpose of competency assessment? a. Identify employees in need of retraining b. Evaluate an individual’s level of knowledge during a job interview c. Identify employees who need to be fired d. All of the above Which of the following is most likely to activate the alternative pathway of complement activation? a. Lipopolysaccharides b. Glycoproteins c. Haptens d. lgG complexed with antigen The transfusion service is preparing aliquots from a unit of Red Blood Cells Leukocytes Reduced with the aid of a sterile connecting device for a pediatric patient. When checking the weld for one of these aliquots, it is noted that the weld is incomplete and leaking. This unit is then resealed with an acceptable weld. What will the expiration date of this unit be? a. 6 hours b. 24 hours c. 3 days d. Original expiration date A technologist removed 4 units of blood from the blood bank refrigerator and placed them on the counter. A clerk was waiting to take the units for transfusion. As she checked the paperwork, she noticed that one of the units was leaking onto the counter. What should she do? a. Issue the unit if the red cells appear normal b. Reseal the unit c. Discard the unit d. Call the medical director and ask for an opinion Traditional example of quality control: a. Error-free quality b. Management controlled worker c. Quality as means to lower cost d. Quality defined → Traditional vs TQM Thinking All blood banks as mandated by law must have a: a. Water fountain b. Written laboratory safety program c. BSC d. Foot-operated hand wash 1 15. Focus on people and operational delivery of laboratory services: a. Laboratory supervisor b. Laboratory manager or chief MT c. Laboratory director d. Administrator → Laboratory directors and administrators ▪ Retain ultimate responsibility in achieving goals e.g. changes in technology, capital investments, and services rendered are finalized by this level of laboratory management → Laboratory managers or chief technologists ▪ Create and maintain an environment for laboratory professionals to function efficiently ▪ Plan, organize, direct, and control job 16. In the urinalysis laboratory the primary source in the chain of infection would be: a. Patients b. Needlesticks c. Specimens d. Biohazardous waste 17. The best way to break the chain of infection is: a. Handwashing b. Personal protective equipment c. Aerosol prevention d. Decontamination 18. An employee can learn the carcinogenic potential of potassium chloride by consulting the: a. Chemical hygiene plan b. Material safety data sheets c. OSHA standards d. Urinalysis procedure manual 19. Blood vessel that supply blood to the kidney: a. Renal artery b. Renal vein c. Peritubular capillaries d. None of these 20. The only tissue in the body that is hypertonic with respect to normal plasma (i.e., its osmolality is greater than 290 mOsm/kg): a. Glomerulus b. Convoluted tubules c. Renal cortex d. Renal medulla → more concentrated than plasma 21. Ultrafiltration: a. Chemical filtration b. Mechanical filtration c. Both of these d. None of these 22. Composition of urine: a. Organic chemicals dissolved in water b. Inorganic chemicals dissolved in water c. Organic and inorganic chemicals d. Organic and inorganic chemicals dissolved in water 23. Which of the following is passively reabsorbed? a. Amino acids b. Chloride c. Glucose d. Urea 24. The correct method for labeling urine specimen containers is to: a. Attach the label to the lid b. Attach the label to the bottom c. Attach the label to the container d. Use only a wax pencil for labeling 25. Urine preservative that maintains the pH at about 6.0 and preserves protein and formed elements well without interfering with routine testing except for pH. a. Boric acid b. Toluene c. Formalin d. Phenol → Urine preservatives: ▪ Formalin - Excellent sediment preservative Acts as a reducing agent, interfering with chemical tests for glucose, blood, leukocyte esterase, and copper reduction ▪ Boric Acid - Preserves protein and formed elements well; does not interfere with routine analyses other than pH ▪ Toluene - Does not interfere with routine tests 26. Polyuria in adults: a. Greater than 1.5 L urine/day b. Greater than 2.0 L urine/day c. Greater than 2.5 L urine/day d. Greater than 3.0 L urine/day → Urine output: ▪ The normal daily urine output is usually 1200 to 1500 mL, a range of 600 to 2000 mL is considered normal. ▪ Polyuria, an increase in daily urine volume (greater than 2.5 L/day in adults and 2.5 to 3 mL/kg/day in children),. ▪ Oliguria, a decrease in urine output (which is less than 1 mL/kg/hr in infants, less than 0.5 mL/kg/hr in children, and less than 400 mL/day in adults). 27. Evaluation of polyuria: a. Culture b. Glucose c. Routine urinalysis d. Urine osmolality 28. Urine solute exhibiting diurnal variation: a. Creatinine b. Glucose c. Nitrite d. 17-hydroxysteroids → Many solutes exhibit diurnal variations such as catecholamines, 17-hydroxysteroids, and electrolytes in which the lowest concentration is in early morning and the highest concentration occurs in afternoon. 29. Phenol derivatives found in certain intravenous medications produce ___ urine on oxidation. a. Amber b. Yellow c. Orange d. Green 30. Calibration of centrifuges is customarily performed every ___. a. Daily b. Weekly c. Monthly d. Every 3 months (quarterly) 2 31. Centrifuges are routinely disinfected on a ___ basis. a. Daily b. Weekly c. Monthly d. Yearly 32. Let refrigerated urine specimens warm to ___ before testing: a. Body temperature b. Room temperature c. 37 °C d. 56 °C 33. Refrigeration may cause precipitation of amorphous urates and phosphates and other nonpathologic crystals that can obscure other elements in the urine sediment. Warming the specimen to ___ prior to centrifuging may dissolve some of these crystals. a. 20 °C b. 37 °C c. 40 °C d. 100 °C 34. Which of the following produces sweet or fruity odor in urine? a. Bacteria b. Ketone c. Methionine d. Phenylalanine 35. The concentration of myoglobin in the urine must be at least ___ before the red pigmentation can be visualized. a. 10 mg/dL b. 15 mg/dL c. 20 mg/dL d. 25 mg/dL 36. A specimen with a specific gravity of 1.005 would be considered: a. Isosthenuric b. Hyposthenuric c. Hypersthenuric d. Not urine → Normal random specimens may range from 1.003 to 1.035, depending on the patient’s amount of hydration. Specimens measuring lower than 1.003 probably are not urine. 37. The reading of distilled water by the refractometer is 1.003. You should: a. Subtract 1.003 from each specimen reading b. Add 1.003 to each specimen reading c. Use a new refractometer d. Adjust the set screw 38. Refractometer results are valid up to ___; specimen with greater than (your answer) should be diluted and remeasured. a. 1.020 b. 1.030 c. 1.035 d. 1.050 39. Urine specific gravity by the reagent strip is 1.020, chemical tests indicate presence of 2 g/dL protein. What is the corrected specific gravity? a. 1.010 b. 1.012 c. 1.014 d. 1.020 40. Urine specific gravity by the refractometer is 1.020. The urine temperature is 17 °C. What is the corrected specific gravity? a. 1.016 b. 1.017 c. 1.019 d. 1.020 → Temperature is compensated between 15 °C and 3°C. → Corrections for glucose and protein are still calculated, although refractometer readings are less affected by particle density than are urinometer readings. 41. Urine specific gravity by the urinometer is 1.032. The urine temperature is 26 °C and chemical tests indicate presence of 2 g/dL protein. What is the corrected specific gravity? a. 1.022 b. 1.024 c. 1.026 d. 1.028 → If the specimen is cold, 0.001 must be subtracted from the reading for every 3 oC that the specimen temperature is below the urinometer calibration temperature. → If the specimen is warm, 0.001 must be added to the reading for every 3 oC that the specimen measures above the calibration temperature. → Each gram of protein present, 0.003 must be subtracted from the specific gravity reading, and 0.004 must be subtracted for each gram of glucose present. 42. The method for determining a urine specific gravity that is based on the principle that the frequency of a sound wave entering a solution changes in proportion to the density of the solution is: a. Colorimetric b. Oscillation densitometry c. Refractometry d. Urinometry 43. A urine sample is received in the laboratory with the appropriate custody control form, and a request for drug of abuse screening. Which test result would be cause for rejecting the sample? a. Temperature after collection 95°F b. pH 5.0 c. Specific gravity 1.005 d. Creatinine 5 mg/dL → Acceptable for urine drug testing ▪ Temperature (90°F to 100°F) ▪ pH (4.5 to 8.0) ▪ Specific gravity (1.003 to 1.019) ▪ Creatinine (≥20 mg/dL) 44. When testing for drugs of abuse in urine, which of the following test results indicate dilution and would be cause for rejecting the sample? a. Temperature upon sample submission 92°F b. Specific gravity 1.002; Creatinine 15 mg/dL c. pH 5.8; temperature 94°F d. Specific gravity 1.012, creatinine 25 mg/dL 3 45. How should controls be run to ensure the precision and accuracy of the reagent test strips used for the chemical analysis of urine? a. Positive controls should be run on a daily basis and negative controls when opening a new bottle of test strips. b. Positive and negative controls should be run when the test strips' expiration date is passed. c. Positive and negative controls should be run on a daily basis. d. Positive controls should be run on a daily basis and negative controls on a weekly basis. 46. All of the following are important to protect the integrity of reagent strips EXCEPT: a. Removing the desiccant from the bottle b. Storing in an opaque bottle c. Storing at room temperature d. Resealing the bottle after removing a strip 47. Which of the following tests is affected least by standing or improperly stored urine? a. Glucose b. Protein c. pH d. Bilirubin 48. The principle of “protein error of indicators” is based on: a. Protein changing the pH of the specimen b. Protein changing the pKa of the specimen c. Protein accepting hydrogen from the indicator d. Protein giving up hydrogen to the indicator 49. Sensitivity of Multistix albumin pad: a. 5 to 10 mg/dL albumin b. 10 to 14 mg/dL albumin c. 15 to 30 mg/dL albumin d. 20 to 30 mg/dL albumin → Albumin Sensitivity: ▪ Multistix = 15 to 30 mg/dL albumin ▪ Chemstrip = 6 mg/dL albumin 50. Daily loss of protein in urine normally does not exceed: a. 30 mg b. 50 mg c. 100 mg d. 150 mg 4