Certified Phlebotomy Technician (CPT) Quiz: Capillary Collection
9 questions · exam conditions
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Capillary CollectionQuestion 1 of 9

A phlebotomist needs to collect capillary blood from a 2-year-old patient for hemoglobin, electrolytes, and liver function tests. The order specifies that all tests are STAT priority. After successful puncture with good blood flow, in what sequence should the specimens be collected to ensure optimal accuracy for all requested tests?

Hemoglobin first to avoid cell count alterations, followed by electrolytes, then liver function tests
Electrolytes first due to STAT priority, followed by hemoglobin, then liver function tests to minimize delays
Liver function tests first since they require the largest volume, followed by hemoglobin, then electrolytes
Collect all specimens simultaneously in one large tube, then aliquot into separate containers for each test type
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Certified Phlebotomy Technician (CPT) Quiz

Certified Phlebotomy Technician (CPT) Quiz: Capillary Collection

Practice Capillary Collection in Certified Phlebotomy Technician (CPT) with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Capillary Collection, giving you a quick way to practice the rules, question types, and explanations that matter most for Certified Phlebotomy Technician (CPT).

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

A phlebotomist needs to collect capillary blood from a 2-year-old patient for hemoglobin, electrolytes, and liver function tests. The order specifies that all tests are STAT priority. After successful puncture with good blood flow, in what sequence should the specimens be collected to ensure optimal accuracy for all requested tests?

  1. Hemoglobin first to avoid cell count alterations, followed by electrolytes, then liver function tests (correct answer)
  2. Electrolytes first due to STAT priority, followed by hemoglobin, then liver function tests to minimize delays
  3. Liver function tests first since they require the largest volume, followed by hemoglobin, then electrolytes
  4. Collect all specimens simultaneously in one large tube, then aliquot into separate containers for each test type
Explanation: When collecting capillary blood specimens from pediatric patients, you must consider the order of draw to prevent contamination and ensure accurate results. Unlike venipuncture where you follow tube additive sequences, capillary collection prioritizes tests most susceptible to contamination or hemolysis. Option A is correct because hemoglobin testing should always come first in capillary collection. Cell counts and hemoglobin values are extremely sensitive to hemolysis, platelet clumping, and microcellular changes that occur as blood sits exposed to air. Even minimal hemolysis from prolonged collection can falsely elevate hemoglobin readings and compromise hematologic accuracy. Option B incorrectly prioritizes based on STAT status rather than specimen integrity. While all tests are STAT, electrolytes are less sensitive to brief delays than hematologic parameters. Sodium and potassium levels remain stable longer than cellular components. Option C misunderstands capillary collection principles. Volume requirements don't determine collection order in capillary draws—specimen stability does. Additionally, liver function tests typically require less volume than assumed here, and collecting them first could compromise the more fragile hematologic specimen. Option D represents a fundamental error in laboratory practice. You cannot collect different test types in one tube and aliquot later, as different tests require specific additives, anticoagulants, or processing methods. This approach would invalidate all results and violate standard laboratory protocols. Remember this sequence for capillary draws: hematology first (most fragile), then chemistry tests like electrolytes and liver functions. Think "fragile first" when blood is exposed to air.

Question 2

While performing a dermal puncture on a newborn's heel for PKU screening and glucose testing, the phlebotomist notices the puncture site continues to bleed excessively after collecting both specimens. The bleeding does not stop after 5 minutes of direct pressure. What is the most appropriate next step?

  1. Apply additional pressure for another 10 minutes and document the extended bleeding time in the patient record
  2. Apply a pressure bandage and notify the nurse or physician immediately about the prolonged bleeding (correct answer)
  3. Apply a small adhesive bandage and instruct the parents to monitor the site for continued bleeding
  4. Elevate the foot above heart level while maintaining pressure and wait for natural clotting to occur
Explanation: Bleeding that continues beyond 5 minutes with direct pressure in a newborn indicates a potential bleeding disorder or other serious condition requiring immediate medical attention. This is beyond the scope of practice for a phlebotomist and requires physician evaluation. A pressure bandage provides immediate control while awaiting medical intervention. Options A and D delay necessary medical care, while option C fails to recognize the seriousness of prolonged bleeding in a newborn.

Question 3

A phlebotomist performs a dermal puncture on a 6-month-old infant's heel for bilirubin testing. After making the puncture, the first drop of blood appears normal, but subsequent drops are noticeably hemolyzed (pink-tinged plasma). The puncture technique appeared correct and the lancet depth was appropriate. What is the most likely cause of this hemolysis?

  1. The lancet depth was actually too shallow, causing cellular damage as blood was forced through a small opening
  2. Normal physiological hemolysis in infants due to immature red blood cell membranes and higher fragility
  3. The infant's heel was positioned too low, creating excessive pressure that damaged cells during collection
  4. Excessive massaging or pressure applied to the site caused mechanical destruction of red blood cells (correct answer)
Explanation: When you encounter hemolysis during dermal puncture, you need to distinguish between technique-related causes and other factors. Hemolysis in capillary blood collection is almost always preventable and indicates a procedural issue. The correct answer is D because excessive massaging, squeezing, or applying pressure to force blood flow mechanically destroys red blood cells. When you apply too much pressure to the puncture site, you're essentially crushing the delicate RBCs as they move through the capillaries and puncture opening. This is the most common cause of hemolysis in dermal punctures and explains why the first drop was normal (initial blood flow was natural) but subsequent drops became hemolyzed (as pressure was applied to maintain flow). Answer A is incorrect because shallow punctures typically result in inadequate blood flow, not hemolysis. If anything, a too-shallow puncture would make it harder to collect blood, requiring more pressure (which would then lead to option D's scenario). Answer B misrepresents infant physiology. While newborn RBCs do have shorter lifespans, they don't spontaneously hemolyze during collection more than adult cells. Proper technique should yield non-hemolyzed samples regardless of age. Answer C is wrong because heel positioning affects blood flow and collection ease, but doesn't directly cause mechanical hemolysis of the cells themselves. Study tip: Remember that hemolysis in dermal punctures is almost always technique-related. Practice the "free-flowing" principle: allow blood to flow naturally without squeezing or excessive pressure. If flow is inadequate, warm the site or make a deeper puncture rather than applying pressure.

Question 4

While collecting capillary blood for multiple tests from a 1-year-old patient, the phlebotomist fills one microcollection tube completely but notices air bubbles throughout the specimen. The blood flow is still adequate for additional collections needed. What is the most appropriate action regarding the tube with air bubbles?

  1. Gently tap the tube to move bubbles to the top, then invert according to manufacturer recommendations for mixing
  2. Continue with remaining collections and note the presence of air bubbles on the specimen label for laboratory review
  3. Discard the tube with air bubbles and recollect the specimen using proper technique to minimize air incorporation (correct answer)
  4. Centrifuge the tube immediately to separate air bubbles from the blood before proceeding with additional collections
Explanation: Air bubbles in blood specimens can interfere with automated testing and affect results accuracy. The specimen should be recollected using proper technique to avoid air incorporation. Since blood flow is still adequate, recollection is feasible and necessary for specimen integrity. Tapping (option A) may not remove all bubbles and mixing could worsen the problem. Noting bubbles (option B) passes a known problem to the laboratory. Immediate centrifugation (option D) is not practical during active collection and may not solve the problem.

Question 5

A phlebotomist needs to collect capillary blood for hemoglobin, potassium, and blood culture from a 2-year-old patient. The pediatrician specifically requests capillary collection due to the patient's dehydration and poor venous access. How should the phlebotomist proceed with this request?

  1. Collect hemoglobin first, then potassium, and explain that blood culture requires venipuncture or central line access (correct answer)
  2. Perform all three collections using sterile technique with hemoglobin first, potassium second, and blood culture last
  3. Collect potassium first to minimize electrolyte changes, followed by hemoglobin, then attempt blood culture collection
  4. Use a larger gauge lancet to increase blood flow and collect all specimens simultaneously in a single collection tube
Explanation: Blood cultures cannot be reliably collected via capillary puncture due to high contamination risk and inadequate volume. The proper capillary order is hemoglobin (hematology) first, then potassium (chemistry). The phlebotomist must explain to the physician that blood culture requires venous access or discuss alternative collection methods. Options B and C incorrectly suggest blood culture is possible via capillary collection, while option D violates proper collection procedures.

Question 6

During a dermal puncture procedure on an elderly diabetic patient, the phlebotomist selects the lateral aspect of the middle finger and uses a 2.0mm depth lancet. After puncturing, blood flow is adequate, but the patient complains of sharp, shooting pain radiating down the finger. What should the phlebotomist's immediate response be?

  1. Continue collection quickly to minimize patient discomfort while maintaining gentle pressure around the puncture site
  2. Stop the procedure immediately, apply pressure to control bleeding, and select an alternative collection site (correct answer)
  3. Reduce the depth of massage and apply a warm compress to improve circulation and reduce pain sensation
  4. Switch to the same finger on the opposite hand using identical technique since the pain is likely temporary
Explanation: Sharp, shooting pain radiating down the finger indicates possible nerve damage from the puncture. This requires immediate cessation of the procedure to prevent further injury. The 2.0mm depth may be excessive for this patient, and continuing collection could worsen nerve damage. A new site should be selected with appropriate depth adjustment. The other options ignore the serious nature of potential nerve injury.

Question 7

A phlebotomist is preparing to collect capillary blood from a 3-year-old patient for hemoglobin and glucose testing. The child has small hands with cool, pale fingers showing poor circulation. The parent mentions the child has been fasting for 12 hours. What preparation step would be most effective for ensuring successful collection?

  1. Select the thumb for puncture since it has the largest surface area and best blood supply in small children
  2. Warm the selected finger with a heel warmer for 3-5 minutes before cleaning and performing the puncture (correct answer)
  3. Use a deeper lancet setting to compensate for the poor circulation and ensure adequate blood flow
  4. Have the parent hold the child's hand in warm water for 10 minutes to improve circulation before collection
Explanation: Warming the site increases local blood circulation and improves capillary blood flow, making collection easier and more successful. Heel warmers applied to fingers for 3-5 minutes are standard practice for patients with poor circulation. The thumb (option A) is not recommended for capillary puncture due to increased nerve density. Deeper punctures (option C) increase injury risk without addressing circulation. Water immersion (option D) can affect glucose results and is impractical for maintaining sterility.

Question 8

A phlebotomist is collecting capillary blood from a 4-year-old patient for complete blood count and comprehensive metabolic panel. After making the puncture on the ring finger, the blood flow starts well but then slows significantly. The phlebotomist has collected about half the needed volume for the CBC. What technique should be used to improve blood flow while maintaining specimen integrity?

  1. Apply firm, continuous pressure around the puncture site while simultaneously massaging toward the fingertip
  2. Gently massage the finger from base to tip in a milking motion, avoiding direct pressure on the puncture site
  3. Make a second puncture adjacent to the first one to increase the collection surface area and blood flow
  4. Apply intermittent gentle pressure around the puncture site while allowing natural blood flow between compressions (correct answer)
Explanation: Intermittent gentle pressure around (not on) the puncture site stimulates blood flow while avoiding hemolysis and excessive tissue fluid contamination. Continuous firm pressure (option A) and milking motions (option B) can cause hemolysis and increase tissue fluid contamination. Making a second puncture (option C) increases infection risk and is unnecessary. The technique should maintain specimen quality while encouraging adequate flow.

Question 9

During capillary collection from an infant's heel, the phlebotomist accidentally touches the collection device to the skin surface around the puncture site. The device now contains blood mixed with skin cells and tissue debris. There is still adequate blood flow from the puncture site. What should the phlebotomist do?

  1. Continue using the same collection device since the contamination is minimal and blood flow is adequate
  2. Wipe the collection device clean with alcohol and continue collection to avoid wasting the specimen
  3. Discard the contaminated collection device, obtain a new sterile device, and continue collection from the same site (correct answer)
  4. Complete the collection with the current device but note the contamination on the specimen label for laboratory reference
Explanation: Any contamination of the collection device with skin cells, tissue debris, or non-blood material compromises specimen integrity and can affect test results. The device must be discarded and replaced with a sterile collection device. Since blood flow is still adequate, collection can continue from the same puncture site with the new device. Options A and D accept compromised specimens, while option B incorrectly suggests alcohol cleaning can restore sterility.