CC 2

A patient recently consumed serotonin-rich foods such as banana, pineapple, tomato, and avocado. Which specimen characteristic may be observed?

A. Decreased turbidity

B. Increased turbidity or lactescence

C. Decreased albumin concentration

D. Increased bilirubin degradation

E. Decreased triglyceride concentration

Which statement BEST describes a critical value?

A. A result outside the reference interval but never requiring notification

B. A test result indicating a potentially life-threatening situation

C. A result obtained from a diluted specimen

D. A result that requires calibration

E. A result obtained from a control specimen

Answer: A. Ketonemia or severe metabolic disturbance

Rationales:

A — Correct: Critically abnormal glucose, particularly severe hyperglycemia, may be associated with ketosis/ketoacidosis and can be life-threatening.

B — Incorrect: Hemolysis is a specimen problem, not the primary implication of critical glucose.

C — Incorrect: Iron deficiency does not explain a critical glucose result.

D — Incorrect: Respiratory alkalosis primarily involves blood gases.

E — Incorrect: Bilirubin is a separate analyte.

A critically abnormal serum glucose result may indicate:

A. Ketonemia or severe metabolic disturbance

B. Hemolysis only

C. Iron deficiency only

D. Respiratory alkalosis only

E. Hyperbilirubinemia only

Answer: B. They may cause serious cardiac or neurologic complications

Rationales:

A — Incorrect: Electrolyte abnormalities are not specific to liver disease.

B — Correct: Severe electrolyte disturbances, especially K⁺ abnormalities, can produce cardiac arrhythmias/cardiac arrest.

C — Incorrect: Sodium and potassium are major extracellular/intracellular electrolytes with systemic effects.

D — Incorrect: Hemolysis can falsely increase potassium, but not every abnormal result is due to hemolysis.

E — Incorrect: Severe electrolyte abnormalities can be medical emergencies.

Why are critically abnormal Na⁺ and K⁺ results especially important?

A. They always indicate liver disease

B. They may cause serious cardiac or neurologic complications

C. They only affect urine concentration

D. They indicate hemolysis in every case

E. They have no immediate clinical significance

Answer: A. Acid-base disturbance

Rationales:

A — Correct: Total CO₂ and blood gases are important in evaluating acidosis and alkalosis.

B — Incorrect: Iron deficiency is evaluated using iron studies and hematologic parameters.

C — Incorrect: Hyperlipidemia concerns lipids such as cholesterol and triglycerides.

D — Incorrect: Hemolysis is a specimen interference.

E — Incorrect: Bilirubin reflects heme metabolism.

Critically abnormal total CO₂ and blood gas results are particularly important because they can indicate:

A. Acid-base disturbance

B. Iron deficiency

C. Hyperlipidemia

D. Hemolysis

E. Increased bilirubin production

Answer: B. Tetany and cardiac abnormalities

Rationales:

A — Incorrect: Ketones are related primarily to carbohydrate/fat metabolism.

B — Correct: Severe calcium and magnesium disturbances can cause neuromuscular manifestations such as tetany and cardiac abnormalities.

C — Incorrect: Bilirubin is unrelated to the primary effect described.

D — Incorrect: Lactescence refers to a turbid/milky specimen appearance.

E — Incorrect: Urea reflects nitrogen metabolism and renal handling.

Severe abnormalities in Ca²⁺ and Mg²⁺ may be life-threatening because they can cause:

A. Ketonuria only

B. Tetany and cardiac abnormalities

C. Hyperbilirubinemia only

D. Increased lactescence

E. Increased urea production

Answer: B. It can lead to kernicterus

Rationales:

A — Incorrect: Bilirubin does not cause analyzer hemolysis.

B — Correct: Severe neonatal hyperbilirubinemia can cause bilirubin deposition in the brain (kernicterus).

C — Incorrect: Hyperkalemia is not the direct concern.

D — Incorrect: Lipemia is associated with increased lipids.

E — Incorrect: Bilirubin does not characteristically decrease lactate.

Why can a critically abnormal total bilirubin be considered an emergency, particularly in neonates?

A. It causes hemolysis in the analyzer

B. It can lead to kernicterus

C. It causes hyperkalemia directly

D. It produces lipemia

E. It causes decreased lactate

Answer: C. Hemolyzed specimen when the test is affected by hemolysis

Rationales:

A — Incorrect: Proper collection is desirable.

B — Incorrect: The correct tube is necessary and is not a rejection reason.

C — Correct: Hemolysis can interfere with many laboratory tests and may warrant specimen rejection.

D — Incorrect: Correct labeling is required.

E — Incorrect: Proper transportation

Which of the following is an appropriate reason for specimen rejection?

A. Properly collected specimen

B. Correct collection tube

C. Hemolyzed specimen when the test is affected by hemolysis

D. Correctly labeled specimen

E. Properly transported specimen

Answer: B. Lipemia

Rationales:

A — Incorrect: Hemolysis involves rupture of RBCs and release of intracellular contents.

B — Correct: Lipemia refers to excessive lipid content causing a turbid/milky appearance and potentially interfering with testing.

C — Incorrect: Clots are particularly problematic in anticoagulated specimens.

D — Incorrect: A short draw refers to insufficient specimen volume, especially important with anticoagulant tubes.

E — Incorrect: An incorrect tube is a separate collection error.

Which specimen condition may interfere with laboratory testing because of excessive lipids?

A. Hemolysis

B. Lipemia

C. Clotting

D. Short draw

E. Incorrect tube

Answer: C. Reject the specimen and request recollection

Rationales:

A — Incorrect: Clotted anticoagulated specimens can produce unreliable results.

B — Incorrect: Removing a clot does not restore the original specimen integrity.

C — Correct: Clots in an anticoagulated specimen are a reason for rejection and recollection.

D — Incorrect: Centrifugation does not correct clotting.

E — Incorrect: Adding EDTA after collection is inappropriate.

A CBC specimen collected in an EDTA tube contains visible clots. What is the MOST appropriate action?

A. Report the result immediately

B. Remove the clot and continue testing

C. Reject the specimen and request recollection

D. Centrifuge the specimen

E. Add more EDTA

Answer: B. Reject or recollect the specimen according to the test requirement

Rationales:

A — Incorrect: Food intake may alter tests requiring fasting.

B — Correct: A nonfasting specimen when fasting is required can be a reason for rejection/recollection.

C — Incorrect: Anticoagulant does not correct dietary effects.

D — Incorrect: Freezing does not correct a nonfasting state.

E — Incorrect: Dilution cannot correct physiologic changes caused by food intake.

A test specifically requires a fasting specimen, but the patient reports eating breakfast before collection. What should the laboratory consider?

A. Automatically report the result

B. Reject or recollect the specimen according to the test requirement

C. Add anticoagulant

D. Freeze the specimen

E. Dilute the specimen

Answer: C. Consider the specimen unacceptable and request recollection

Rationales:

A — Incorrect: Tube additives can directly affect test results.

B — Incorrect: Additives should not be added after collection.

C — Correct: An incorrect collection tube is a common reason for specimen rejection.

D — Incorrect: Dilution cannot correct an inappropriate additive.

E — Incorrect: Transferring blood between tubes can cause contamination and incorrect blood-to-additive ratios.

A specimen was collected in the wrong blood collection tube. What is the BEST laboratory action?

A. Ignore the tube type

B. Add the correct additive afterward

C. Consider the specimen unacceptable and request recollection

D. Dilute the specimen

E. Transfer the specimen into the correct tube

Answer: C. Transporting a temperature-sensitive specimen under the wrong temperature conditions

Rationales:

A — Incorrect: Correct temperature preserves specimen integrity.

B — Incorrect: Prompt delivery is generally desirable.

C — Correct: Improper transport temperature can alter analyte concentrations and make the specimen unsuitable.

D — Incorrect: Correct containers are required.

E — Incorrect: Light protection preserves light-sensitive analytes such as bilirubin.

Which is an example of improper specimen transport that can result in rejection?

A. Following the required transport temperature

B. Promptly delivering the specimen

C. Transporting a temperature-sensitive specimen under the wrong temperature conditions

D. Using the required container

E. Protecting light-sensitive specimens from light

Answer: C. Short draw

Rationales:

A — Incorrect: Lipemia involves increased lipids/turbidity.

B — Incorrect: Hemolysis involves RBC rupture.

C — Correct: A short draw means insufficient specimen volume was collected.

D — Incorrect: Clotting is inappropriate clot formation in an anticoagulated specimen.

E — Incorrect: Icterus refers to increased bilirubin/yellow discoloration.

Which specimen collection problem refers to obtaining insufficient blood volume?

A. Lipemia

B. Hemolysis

C. Short draw

D. Clotting

E. Icterus

Answer: C. Sodium citrate

Rationales:

A — Incorrect: EDTA is typically found in lavender/purple-top tubes.

B — Incorrect: Lithium heparin is found in green-top tubes.

C — Correct: Light blue = sodium citrate, used primarily for coagulation testing.

D — Incorrect: Sodium fluoride is associated with gray-top tubes.

E — Incorrect: Clot activator is found in serum tubes.

Which additive is found in a light-blue-top tube?

A. EDTA

B. Lithium heparin

C. Sodium citrate

D. Sodium fluoride

E. Clot activator

Answer: B. Preserve labile clotting factors and prevent coagulation

Rationales:

A — Incorrect: Sodium citrate functions as an anticoagulant.

B — Correct: Sodium citrate binds calcium reversibly, preventing coagulation while preserving coagulation factors for testing.

C — Incorrect: Gel separators perform the physical separation function.

D — Incorrect: Citrate does not lyse RBCs.

E — Incorrect: Citrate does not increase glucose.

What is the PRIMARY function of sodium citrate in the light-blue tube?

A. Activate clotting

B. Preserve labile clotting factors and prevent coagulation

C. Separate serum from cells

D. Lyse red blood cells

E. Increase glucose concentration

Answer: B. Citrate, ALP, calcium, and phosphorus

Rationales:

A — Incorrect: These are not the carryover effects listed.

B — Correct: The notes specifically list citrate, ALP, calcium, and phosphorus as affected by citrate additive carryover.

C — Incorrect: Urea and creatinine are not the listed citrate carryover tests.

D — Incorrect: CK and LD are not the listed effects.

E — Incorrect: These are not the listed citrate carryover effects.

Carryover of sodium citrate from a light-blue tube can affect which chemistry analytes?

A. Bilirubin and glucose

B. Citrate, ALP, calcium, and phosphorus

C. Urea and creatinine only

D. CK and LD only

E. Ammonia and lactate only

Answer: D. None

Rationales:

A — Incorrect: Sodium citrate is found in light-blue tubes.

B — Incorrect: EDTA is found in lavender/purple tubes.

C — Incorrect: Lithium heparin is found in green tubes.

D — Correct: The red glass tube is listed as having no additive.

E — Incorrect: Red plastic tubes may contain clot activator, but the red glass tube shown is nonadditive.

Which tube contains no additive and is traditionally associated with a glass?

A. Sodium citrate

B. EDTA

C. Lithium heparin

D. Red tube

E. Clot activator

Answer: B. Clot activator (silica)

Rationales:

A — Incorrect: Sodium citrate = light blue.

B — Correct: Red plastic = clot activator, commonly silica.

C — Incorrect: Lithium heparin = green.

D — Incorrect: EDTA = lavender/purple.

E — Incorrect: Sodium fluoride is associated with gray tubes.

What additive is found in a red plastic-top tube?

A. Sodium citrate

B. Clot activator (silica)

C. Lithium heparin

D. EDTA

E. Sodium fluoride

Answer: C. Green/gray or light green

Rationales:

A — Incorrect: Red glass contains no additive.

B — Incorrect: Light blue contains sodium citrate.

C — Correct: Green/gray or light-green tubes contain lithium heparin and gel separator according to the provided table.

D — Incorrect: Red plastic contains clot activator.

E — Incorrect: Lavender contains EDTA.

Which tube contains lithium heparin and a gel separator?

A. Red glass

B. Light blue

C. Green/gray or light green

D. Red plastic

E. Lavender

Answer: C. Lithium heparin

Rationales:

A — Incorrect: Sodium citrate = light blue.

B — Incorrect: Clot activator = red plastic/serum tubes.

C — Correct: Green-top = lithium heparin.

D — Incorrect: EDTA is found in lavender/purple tubes.

E — Incorrect: Sodium fluoride is typically associated with gray-top tubes.

A chemistry specimen is collected in a green-top tube. Which additive should the technologist expect?

A. Sodium citrate

B. Clot activator

C. Lithium heparin

D. EDTA

E. Sodium fluoride

Answer: C. Sodium fluoride

Rationales:

A — Incorrect: EDTA is found in lavender/pink tubes.

B — Incorrect: Sodium citrate is found in light-blue tubes.

C — Correct: Gray tubes contain sodium fluoride, commonly used to inhibit glycolysis.

D — Incorrect: Lithium heparin is found in green tubes.

E — Incorrect: SPS is found in yellow tubes for blood culture collection.

Which additive is primarily found in a gray-top tube?

A. EDTA

B. Sodium citrate

C. Sodium fluoride

D. Lithium heparin

E. Sodium polyanethol sulfonate

Answer: B. Sodium fluoride + potassium oxalate

Rationales:

A — Incorrect: These are different anticoagulants used for different purposes.

B — Correct: Gray tubes may contain sodium fluoride and potassium oxalate.

C — Incorrect: This describes certain green tubes.

D — Incorrect: EDTA and silica are not the standard gray combination.

E — Incorrect: SPS and ACD are yellow-top additives.

Which combination is associated with a gray-top tube?

A. Sodium citrate + EDTA

B. Sodium fluoride + potassium oxalate

C. Lithium heparin + gel separator

D. EDTA + silica

E. SPS + ACD

Answer: B. Prevent glycolysis

Rationales:

A — Incorrect: Sodium fluoride does not activate coagulation.

B — Correct: Sodium fluoride inhibits glycolysis, helping preserve glucose concentration.

C — Incorrect: Clot activators promote clot formation.

D — Incorrect: Sodium citrate binds calcium.

E — Incorrect: EDTA is used to preserve cellular morphology.

What is the principal purpose of sodium fluoride in a gray-top tube?

A. Activate coagulation

B. Prevent glycolysis

C. Promote clot formation

D. Bind calcium reversibly

E. Preserve WBC morphology

Answer: C. Sodium polyanethol sulfonate (SPS)

Rationales:

A — Incorrect: EDTA is primarily used for hematology.

B — Incorrect: Sodium fluoride is used primarily to inhibit glycolysis.

C — Correct: SPS is used as an anticoagulant/preservative in blood culture collection.

D — Incorrect: Lithium heparin is commonly used for plasma chemistry.

E — Incorrect: Potassium oxalate may be combined with sodium fluoride in gray tubes.

Which tube additive is associated with blood culture collection?

A. EDTA

B. Sodium fluoride

C. Sodium polyanethol sulfonate (SPS)

D. Lithium heparin

E. Potassium oxalate

Answer: B. Sodium polyanethol sulfonate

Rationales:

A — Incorrect: ACD is another yellow-tube additive used for specialized purposes.

B — Correct: SPS is associated with yellow tubes for blood culture collection.

C — Incorrect: EDTA = lavender/pink.

D — Incorrect: Sodium fluoride = gray.

E — Incorrect: Thrombin is associated with orange tubes.

Which additive is found in a yellow-top tube used for blood cultures?

A. Acid citrate dextrose

B. Sodium polyanethol sulfonate

C. EDTA

D. Sodium fluoride

E. Thrombin

Answer: A. Acid citrate dextrose

Rationales:

A — Correct: ACD = Acid Citrate Dextrose, represented by one type of yellow tube.

B — Incorrect: Sodium fluoride is associated with gray tubes.

C — Incorrect: Lithium heparin is associated with green tubes.

D — Incorrect: EDTA is associated with lavender/pink tubes.

E — Incorrect: ACD contains citrate plus dextrose.

Which additive is found in a yellow tube containing ACD?

A. Acid citrate dextrose

B. Sodium fluoride

C. Lithium heparin

D. EDTA

E. Sodium citrate only

Answer: A. Thrombin

Rationales:

A — Correct: Orange tubes contain thrombin, a rapid clot activator.

B — Incorrect: EDTA is used in lavender/pink tubes.

C — Incorrect: Sodium citrate is used in light-blue tubes.

D — Incorrect: SPS is found in yellow tubes.

E — Incorrect: Potassium oxalate may be found in gray tubes.

Which additive is associated with an orange-top tube?

A. Thrombin

B. EDTA

C. Sodium citrate

D. SPS

E. Potassium oxalate

Answer: C. No additive

Rationales:

A — Incorrect: Royal-blue tubes with lavender labels may contain EDTA.

B — Incorrect: Royal-blue tubes with green labels may contain sodium heparin.

C — Correct: The red-label royal-blue tube contains no additive.

D — Incorrect: Sodium fluoride is associated with gray tubes.

E — Incorrect: SPS is associated with yellow tubes.

Which additive is associated with the royal-blue tube with a red label?

A. EDTA

B. Sodium heparin

C. No additive

D. Sodium fluoride

E. SPS

Answer: B. Sodium heparin

Rationales:

A — Incorrect: Lavender-label royal-blue tubes contain EDTA.

B — Correct: A green-label royal-blue tube contains sodium heparin.

C — Incorrect: Sodium citrate is found in light-blue tubes.

D — Incorrect: Thrombin is found in orange tubes.

E — Incorrect: ACD is associated with yellow tubes.

A royal-blue tube has a green label. Which additive should the technologist expect?

A. EDTA

B. Sodium heparin

C. Sodium citrate

D. Thrombin

E. ACD

Answer: C. EDTA

Rationales:

A — Incorrect: Sodium fluoride is associated with gray tubes.

B — Incorrect: Sodium heparin is associated with green-label royal-blue tubes.

C — Correct: Lavender-label royal-blue = EDTA.

D — Incorrect: SPS = yellow.

E — Incorrect: Thrombin = orange.

Which additive is associated with a royal-blue tube with a lavender label?

A. Sodium fluoride

B. Sodium heparin

C. EDTA

D. SPS

E. Thrombin

Answer: B. Sodium heparin

Rationales:

A — Incorrect: EDTA is associated with tan plastic tubes.

B — Correct: Tan glass = sodium heparin according to the provided table.

C — Incorrect: Sodium citrate = light blue.

D — Incorrect: SPS = yellow.

E — Incorrect: Sodium fluoride = gray.

Which additive is present in a tan glass tube?

A. EDTA

B. Sodium heparin

C. Sodium citrate

D. SPS

E. Sodium fluoride

Answer: B. EDTA

Rationales:

A — Incorrect: Sodium heparin is listed for the tan glass tube.

B — Correct: Tan plastic = EDTA in the provided reference.

C — Incorrect: Thrombin = orange.

D — Incorrect: SPS = yellow.

E — Incorrect: Sodium citrate = light blue.

Which additive is present in a tan plastic tube?

A. Sodium heparin

B. EDTA

C. Thrombin

D. SPS

E. Sodium citrate

Answer: C. Heparin

Rationales:

A — Incorrect: EDTA is excellent for preserving blood cell morphology but is not identified in the notes as the best anticoagulant for preventing hemolysis.

B — Incorrect: Sodium citrate is primarily used for coagulation studies.

C — Correct: The notes identify heparin as the best anticoagulant for prevention of hemolysis.

D — Incorrect: Potassium oxalate is used with fluoride in gray tubes.

E — Incorrect: Sodium fluoride primarily inhibits glycolysis.

Which anticoagulant is described as the best anticoagulant for prevention of hemolysis in the provided notes?

A. EDTA

B. Sodium citrate

C. Heparin

D. Potassium oxalate

E. Sodium fluoride

Answer: A. EDTA

Rationales:

A — Correct: EDTA is preferred for hematologic testing because it preserves cellular morphology well.

B — Incorrect: Sodium fluoride is primarily a glycolysis inhibitor.

C — Incorrect: Sodium citrate is primarily used for coagulation testing.

D — Incorrect: Thrombin promotes clot formation.

E — Incorrect: SPS is used in blood culture collection.

Which anticoagulant produces minimal morphologic changes to WBCs?

A. EDTA

B. Sodium fluoride

C. Sodium citrate

D. Thrombin

E. SPS

Answer: B. Potassium

Rationales:

A — Incorrect: EDTA contamination can markedly decrease calcium by chelating it.

B — Correct: Some EDTA formulations contain potassium, potentially causing falsely increased K⁺.

C — Incorrect: Chloride is not the classic EDTA contamination finding.

D — Incorrect: Bicarbonate is not the classic effect.

E — Incorrect: Sodium is not the primary concern.

Which electrolyte may be falsely increased because of EDTA contamination?

A. Calcium

B. Potassium

C. Chloride

D. Bicarbonate

E. Sodium only

Answer: B. ↑ K⁺ and ↓ Ca²⁺, Fe

Rationales:

A — Incorrect: This is opposite of the typical EDTA contamination pattern.

B — Correct: EDTA contamination can produce pseudohyperkalemia and hypocalcemia.

C — Incorrect: Potassium may increase rather than decrease.

D — Incorrect: Calcium is typically decreased because EDTA chelates calcium.

E — Incorrect: EDTA can significantly affect electrolyte measurements.

EDTA contamination may cause which combination of results?

A. ↓ K⁺ and ↑ Ca²⁺, Fe

B. ↑ K⁺ and ↓ Ca²⁺, Fe

C. ↓ K⁺ and ↓ Ca²⁺ ↓Fe

D. ↑ Ca²⁺ and ↑ K⁺ ↑Fe

E. No effect on electrolytes

Answer: B. Ask the patient to state their full name

Rationales:

A — Incorrect: Room number is not sufficient patient identification.

B — Correct: For a conscious patient, verbally ask the patient for their full name.

C — Incorrect: Another patient cannot reliably identify the patient.

D — Incorrect: Visual recognition alone is unsafe.

E — Incorrect: The notes specify the full name.

A conscious patient is being prepared for phlebotomy. What is the appropriate method of patient identification according to the notes?

A. Ask only the patient's room number

B. Ask the patient to state their full name

C. Ask another patient to identify them

D. Identify the patient by appearance alone

E. Ask the patient only for their first name

Answer: C. Awaken the patient for identification

Rationales:

A — Incorrect: The sleeping patient should not simply be assumed to be correctly identified.

B — Incorrect: Another patient is not an acceptable identifier.

C — Correct: A sleeping patient must be awakened so proper identification can be performed.

D — Incorrect: Room number alone is inadequate.

E — Incorrect: Patient identification is essential before specimen collection.

A patient is sleeping when the phlebotomist arrives. What should be done?

A. Draw blood without waking the patient

B. Ask another patient for identification

C. Awaken the patient for identification

D. Identify the patient using room number

E. Skip patient identification

Answer: B. The attending nurse

Rationales:

A — Incorrect: Visitors are not the appropriate primary identifier.

B — Correct: For an unconscious or mentally incompetent patient, the notes specify asking the attending nurse.

C — Incorrect: Another patient cannot verify identity.

D — Incorrect: Reception staff are not the designated identifier.

E — Incorrect: The notes specifically identify the attending nurse.

An unconscious or mentally incompetent patient requires blood collection. Who should be consulted for patient identification according to the notes?

A. Any available visitor

B. The attending nurse

C. Another patient

D. The laboratory receptionist

E. The phlebotomist's supervisor only

Answer: C. Ask the nurse or relative, or use the ID bracelet

Rationales:

A — Incorrect: A child may not be able to provide reliable identification.

B — Incorrect: Room number alone is insufficient.

C — Correct: For infants and children, identification may be obtained through the nurse/relative or ID bracelet.

D — Incorrect: Every patient requires proper identification.

E — Incorrect: Physical appearance alone is unreliable.

For an infant or child who cannot reliably provide their identity, which is appropriate?

A. Ask the child to guess their name

B. Use the room number alone

C. Ask the nurse or relative, or use the ID bracelet

D. Skip identification

E. Identify only by physical appearance

Answer: B. Perform the modified Allen test

Rationale:

A. Incorrect — ABG collection is performed without a tourniquet.

B. Correct — The modified Allen test assesses collateral circulation before radial artery puncture.

C. Incorrect — Massage is not performed before arterial puncture.

D. Incorrect — Repeated fist clenching is not the required procedure.

E. Incorrect — Positioning may be adjusted for collection, but this is not the essential preliminary test.

A phlebotomist is about to collect an arterial blood gas specimen from a patient's radial artery. Which procedure should be performed FIRST?

A. Apply a tourniquet

B. Perform the modified Allen test

C. Massage the puncture site

D. Ask the patient to clench the fist repeatedly

E. Place the arm below heart level

Answer: C. Arterial blood collected appropriately without a tourniquet

Rationale:

A. Incorrect — EDTA blood is primarily used for hematology.

B. Incorrect — Serum is not the standard specimen for ABG analysis.

C. Correct — Arterial blood is used for blood gas and pH evaluation and is collected without a tourniquet.

D. Incorrect — EDTA plasma is not the standard ABG specimen.

E. Incorrect — Gold-top serum is generally used for chemistry/immunology testing.

Which specimen is MOST appropriate for blood gas analysis?

A. Venous blood collected in EDTA

B. Serum collected in a red tube

C. Arterial blood collected appropriately without a tourniquet

D. Plasma collected in a lavender tube

E. Serum collected in a gold tube

Answer: C. Edematous area

Rationale:

A. Incorrect — The radial artery is a preferred arterial puncture site.

B. Incorrect — The brachial artery may be used when indicated.

C. Correct — Edema, infection, wounds, or irritated areas should be avoided.

D. Incorrect — The femoral artery can be used when clinically indicated.

E. Incorrect — Adequate collateral circulation is desirable, particularly for radial puncture.

Which of the following is an UNACCEPTABLE site for arterial puncture?

A. Normal radial artery

B. Normal brachial artery

C. Edematous area

D. Appropriate femoral artery

E. Site with adequate collateral circulation

Answer: C. 45–60°

Rationale:

A. Incorrect — Too shallow for the technique described.

B. Incorrect — Not the angle specified in the notes.

C. Correct — Radial arterial puncture is performed at approximately 45–60°.

D. Incorrect — Excessively steep for radial artery puncture.

E. Incorrect — 90° is associated with the femoral approach in the provided notes, not radial puncture.

What is the usual angle of needle insertion for radial arterial puncture according to the provided notes?

A. 10–15°

B. 20–30°

C. 45–60°

D. 75–80°

E. 90°

Answer: B. Blood culture → citrate → serum → heparin → EDTA → fluoride

Rationale:

A. Incorrect — EDTA must not precede citrate.

B. Correct — Standard sequence: blood culture → citrate → serum → heparin → EDTA → fluoride/oxalate.

C. Incorrect — Blood cultures should precede serum.

D. Incorrect — Blood culture should come first.

E. Incorrect — Fluoride is collected near the end.

Which sequence represents the CORRECT order of draw?

A. EDTA → citrate → serum → heparin → fluoride

B. Blood culture → citrate → serum → heparin → EDTA → fluoride

C. Serum → blood culture → EDTA → citrate → fluoride

D. Citrate → blood culture → heparin → serum → EDTA

E. Fluoride → EDTA → heparin → serum → citrate

Answer: B. Sodium citrate contamination by EDTA

Rationale:

A. Incorrect — This is not the principal concern.

B. Correct — EDTA carryover into a citrate tube can alter coagulation results, particularly because EDTA chelates calcium.

C. Incorrect — Bilirubin is unrelated to this order-of-draw error.

D. Incorrect — Centrifugation is not the problem.

E. Incorrect — Heparin is not involved in this situation.

A phlebotomist accidentally collects a lavender-top tube before a light-blue tube. What is the PRIMARY concern?

A. Increased glucose concentration

B. Sodium citrate contamination by EDTA

C. Increased serum bilirubin

D. Hemolysis caused by centrifugation

E. Decreased platelet count from heparin

Answer: C. Transfer of an additive from one tube/specimen to another through needle contact

Rationale:

A. Incorrect — This is not specimen additive carryover.

B. Incorrect — Serum separation is different from carryover.

C. Correct — Carryover involves transfer of an additive/specimen component to another tube, potentially causing contamination.

D. Incorrect — This has nothing to do with laboratory specimen collection.

E. Incorrect — Plasma does not transfer into erythrocytes in this context.

What is meant by "carryover" during specimen collection?

A. Transfer of blood from an artery to a vein

B. Transfer of serum during centrifugation

C. Transfer of an additive from one tube/specimen to another through needle contact

D. Transfer of a patient from one hospital room to another

E. Transfer of plasma into erythrocytes

Answer: C. Green — lithium heparin — chemistry

Rationale:

A. Incorrect — Light blue contains sodium citrate, not EDTA.

B. Incorrect — Lavender contains EDTA; light blue is used for PT.

C. Correct — Green = heparin, commonly used for plasma chemistry.

D. Incorrect — SPS is associated with appropriate yellow blood culture tubes; gray is associated with fluoride.

E. Incorrect — EDTA is associated with lavender/pink tubes.

Which combination is CORRECT?

A. Light blue — EDTA — CBC

B. Lavender — sodium citrate — PT

C. Green — lithium heparin — chemistry

D. Gray — SPS — blood culture

E. Yellow — EDTA — CBC

Answer: D. 3–4 inches

Rationale:

A. Incorrect — Too close to the puncture site.

B. Incorrect — Not the distance indicated in the notes.

C. Incorrect — Still below the recommended distance.

D. Correct — The notes specify approximately 3–4 inches above the site.

E. Incorrect — Excessively far from the collection site.

At what approximate distance above the venipuncture site should the tourniquet be placed?

A. 0.5 inch

B. 1 inch

C. 2 inches

D. 3–4 inches

E. 8–10 inches

Answer: C. Vein over an area of edema

Rationale:

A. Incorrect — The median cubital vein is commonly preferred.

B. Incorrect — The cephalic vein is an acceptable venipuncture site.

C. Correct — Edematous areas should be avoided.

D. Incorrect — The basilic vein may be used with appropriate caution.

E. Incorrect — The antecubital area is commonly used for venipuncture.

Which venipuncture site should generally be AVOIDED?

A. Normal median cubital vein

B. Normal cephalic vein

C. Vein over an area of edema

D. Normal basilic vein when appropriate

E. A suitable vein in the antecubital area

Answer: B. A lower gauge number indicates a larger needle diameter.

Rationale:

A. Incorrect — The relationship is the opposite.

B. Correct — Lower gauge = larger diameter; e.g., 20G is larger than 23G.

C. Incorrect — Gauge refers to needle diameter, not length.

D. Incorrect — Needle selection depends on the patient, vein, and procedure.

E. Incorrect — A 30G needle is much smaller in diameter than a 20G needle.

Which statement about needle gauge is CORRECT?

A. A higher gauge number indicates a larger needle diameter.

B. A lower gauge number indicates a larger needle diameter.

C. Gauge refers only to needle length.

D. All venipunctures require a 25-gauge needle.

E. A 30-gauge needle has the largest diameter.

Answer: C. Avoid the affected extremity when possible

Rationale:

A. Incorrect — The affected extremity is generally avoided.

B. Incorrect — Larger veins do not outweigh the potential risks associated with the affected limb.

C. Correct — An extremity affected by mastectomy/lymph node removal is generally avoided when another suitable site is available.

D. Incorrect — Surgical scars are not preferred puncture sites.

E. Incorrect — Prolonged tourniquet application is inappropriate and may worsen complications.

A patient has a history of mastectomy with lymph node removal on one arm. Which is the BEST consideration when selecting a venipuncture site?

A. Always use the arm on the side of lymph node removal

B. Use the affected arm because veins are larger

C. Avoid the affected extremity when possible

D. Perform venipuncture directly over the surgical scar

E. Apply a tourniquet for an extended period on the affected arm