Specimen Temperature
A phlebotomist collects an ammonia specimen but forgets to place it on ice immediately after collection. Which outcome is MOST likely?
A. Slight specimen instability
B. Possible alteration of laboratory results
C. Delayed specimen processing
D. Falsely elevated analyte levels affecting accuracy
Answer: D. Falsely elevated analyte levels affecting accuracy
Why is PKU newborn screening performed on infants?
A. To monitor hydration status
B. To detect metabolic disorders early
C. To evaluate blood clotting ability
D. To determine blood type immediately after birth
Answer: B. To detect metabolic disorders early
Which vein is generally considered the BEST choice for routine venipuncture?
A. Cephalic vein because it is easier to locate in some patients
B. Basilic vein because it is usually larger
C. Median cubital vein because it is stable and has a lower risk of complications
D. Hand veins because they are visible in many patients
Answer: C. Median cubital vein because it is stable and has a lower risk of complications
Why are additives used in blood collection tubes?
A. To help preserve specimen integrity for accurate testing
B. To improve patient identification
C. To reduce venipuncture discomfort
D. To eliminate labeling requirements
Answer: A. To help preserve specimen integrity for accurate testing
Why is a CBC test commonly ordered?
A. To evaluate blood cell components
B. To BEST evaluate red blood cells, white blood cells, and platelets together
C. To measure blood glucose levels only
D. To determine electrolyte balance
Answer: B. To BEST evaluate red blood cells, white blood cells, and platelets together
Why must certain specimens be maintained at specific temperatures during transport?
A. To help maintain specimen integrity
B. To reduce analyte deterioration
C. To support accurate laboratory testing
D. To best preserve analyte stability and ensure reliable results
Answer: D. To best preserve analyte stability and ensure reliable results
Which collection method is MOST appropriate for PKU testing?
A. Venipuncture of the antecubital vein
B. Arterial puncture
C. Heel puncture with filter paper collection
D. Fingerstick puncture
Answer: C. Heel puncture with filter paper collection
Why might a phlebotomist choose the cephalic vein for venipuncture?
A. It may be easier to access in obese patients
B. It is sometimes more visible than deeper veins
C. It has a lower risk of nerve injury than the basilic vein
D. It is often the BEST alternative when the median cubital vein is unavailable
Answer: D. It is often the BEST alternative when the median cubital vein is unavailable
Why is EDTA commonly used in lavender-top tubes?
A. It speeds up clot formation
B. It is the BEST additive for preserving blood cell morphology in hematology testing
C. It separates serum from plasma immediately
D. It increases glucose stability only
Answer: B. It is the BEST additive for preserving blood cell morphology in hematology testing
Why is a lipid panel performed?
A. To assess cholesterol and triglyceride levels related to heart health
B. To evaluate coagulation factors
C. To identify blood type
D. To measure oxygen saturation
Answer: A. To assess cholesterol and triglyceride levels related to heart health
A specimen requiring warming is accidentally placed in an ice slurry. Which action is BEST?
A. Notify laboratory personnel
B. Document the handling error
C. Recollect the specimen if instructed
D. Immediately document the issue and notify appropriate laboratory personnel
Answer: D. Immediately document the issue and notify appropriate laboratory personnel
Why should the filter paper circles be completely filled during PKU specimen collection?
A. To improve specimen quality and testing accuracy
B. To reduce patient identification steps
C. To prevent coagulation testing delays
D. To shorten laboratory processing time only
Answer: A. To improve specimen quality and testing accuracy
Why is extra caution required when drawing from the basilic vein?
A. It is usually difficult to locate
B. It may roll during venipuncture
C. It is located near nerves and arteries
D. It has slower blood flow than hand veins
Answer: C. It is located near nerves and arteries
Why is sodium citrate used in light blue coagulation tubes?
A. It helps maintain accurate coagulation testing by preserving the proper blood-to-additive ratio
B. It destroys coagulation factors
C. It improves bilirubin stability
D. It separates serum during centrifugation
Answer: A. It helps maintain accurate coagulation testing by preserving the proper blood-to-additive ratio
Why is a troponin test commonly ordered in emergency situations?
A. To evaluate kidney function
B. To monitor hydration status
C. To BEST detect markers associated with heart muscle damage
D. To determine platelet count
Answer: C. To BEST detect markers associated with heart muscle damage
Which handling error is MOST likely to compromise a temperature-sensitive specimen?
A. Minor delay in transport
B. Inconsistent storage temperature
C. Failure to monitor transport conditions
D. Delayed transport without proper temperature control
Answer: D. Delayed transport without proper temperature control
When is the BEST time to collect a PKU newborn screening specimen?
A. Immediately after birth before feeding
B. After the infant has fed adequately within the recommended timeframe
C. During the first diaper change only
D. After discharge from the facility
Answer: B. After the infant has fed adequately within the recommended timeframe
Why are hand veins sometimes used for venipuncture?
A. They may provide an alternative when antecubital veins are inaccessible
B. They are often visible in dehydrated patients
C. They can sometimes support specimen collection after multiple failed attempts
D. They are the BEST option when antecubital veins cannot be used safely
Answer: D. They are the BEST option when antecubital veins cannot be used safely
. Why is sodium fluoride commonly used in gray-top tubes?
A. It prevents platelet aggregation
B. It enhances clot formation
C. It BEST preserves glucose levels by slowing glycolysis
D. It improves electrolyte testing accuracy only
Answer: C. It BEST preserves glucose levels by slowing glycolysis
Why is a fasting glucose test performed?
A. To measure white blood cell production
B. To BEST assess blood glucose levels after a required fasting period
C. To evaluate clotting ability
D. To detect electrolyte imbalance only
Answer: B. To BEST assess blood glucose levels after a required fasting period
A phlebotomist is transporting a specimen that must remain at body temperature. Which method is BEST?
A. Keep the specimen covered during transport
B. Deliver the specimen promptly
C. Use temperature-monitored transport procedures
D. Use an approved warming device to maintain the required temperature during transport
Answer: D. Use an approved warming device to maintain the required temperature during transport
A phlebotomist notices the PKU specimen is layered with multiple drops of blood on the filter paper. What is the BEST action?
A. Allow the specimen to dry longer
B. Send the specimen to the laboratory immediately
C. Apply additional blood to the opposite side
D. Follow facility protocol because the specimen may require recollection
Answer: D. Follow facility protocol because the specimen may require recollection
Which characteristic makes the median cubital vein preferred for routine venipuncture?
A. It is typically less likely to roll
B. It is located away from major nerves and arteries
C. It is usually well anchored and easy to palpate
D. It BEST combines stability, accessibility, and safety for venipuncture
Answer: D. It BEST combines stability, accessibility, and safety for venipuncture
Why is heparin commonly found in green-top tubes?
A. It improves coagulation studies
B. It BEST supports plasma specimen collection for many chemistry tests
C. It stabilizes blood glucose only
D. It preserves clot formation during transport
Answer: B. It BEST supports plasma specimen collection for many chemistry tests
Why is a PT/INR test commonly performed?
A. To measure liver enzyme activity
B. To evaluate electrolyte balance
C. To determine blood oxygen levels
D. To BEST monitor blood clotting and anticoagulant effectiveness
Answer: D. To BEST monitor blood clotting and anticoagulant effectiveness