Pediatric Collections

1. Why Pediatric Collections Demand Specialized Skill

Pediatric blood collection is one of the most high-stakes and technique-sensitive procedures in phlebotomy. Unlike adult patients, children vary dramatically in size, physiology, emotional development, and cooperation. A missed collection can mean a painful repeat attempt, increased patient trauma, and compromised sample quality.^[1]

On phlebotomy certification exams (e.g., ASCP, NHA, NCCT), pediatric collections are a high-yield topic. Questions frequently test site selection for different age groups, maximum allowable blood volumes, order of draw in microcollections, and safety considerations to prevent injury or hemolysis.^[2]

Clinically, mastery of pediatric phlebotomy reduces repeat sticks, parental anxiety, specimen rejection rates, and risk of iatrogenic anemia in neonates.^[3]

2. Essential Terminology and Age-Based Differences

Important Terminology

• Heel stick – A capillary puncture performed on the lateral or medial plantar surface of the heel, used primarily in infants under 6–12 months.
• Finger stick – A capillary puncture of the palmar surface of the fingertip, appropriate for older infants, toddlers, and children.
• Winged infusion set (butterfly) – A short, small-gauge butterfly needle with flexible tubing, preferred for pediatric venipuncture due to its maneuverability.
• Microtainer – Small-volume collection tubes designed for capillary blood specimens.
• Iatrogenic anemia – A decrease in hemoglobin caused by repeated blood draws, a significant risk in premature neonates.^[4]
• Maximum allowable blood volume (MABV) – In pediatric patients, typically 1–3% of total blood volume per draw, and no more than 5% over a 30-day period.^[5]
• Order of draw (capillary) – For capillary punctures: blood gas slides, EDTA, other additive tubes, serum tubes (reverse of venipuncture order in some systems).^[6]

Key Differences Between Adult and Pediatric Collections

3. Age-Specific Site Selection and Collection Steps

Site Selection by Age Group

Choosing the correct puncture site is critical for both safety and sample adequacy.^[7]

• Neonates (0–3 months): Heel stick is preferred. Use the lateral (outside) or medial (inside) plantar surface. Avoid the posterior curvature (heel arch) to prevent hitting the calcaneus bone, which can cause osteomyelitis.
• Infants (3–12 months): Heel stick remains common, but a finger stick may be attempted if the infant is older and has adequate tissue. Use the palmar surface of the third or fourth finger.
• Toddlers and young children (1–5 years): Finger stick or venipuncture with a butterfly needle (23–25G). Use dorsal hand veins, cephalic vein, or median cubital if palpable.
• School-age and adolescents (6+ years): Venipuncture using standard techniques. Use a 21–23G butterfly or straight needle based on vein size.

Step-by-Step Pediatric Heel Stick Procedure

1. Prepare the infant: Warm the heel with a commercially approved heel warmer for 3–5 minutes. This increases blood flow by up to 7x.^[8]
2. Select the site: Choose the lateral or medial plantar surface. Do not use the central arch or posterior heel.
3. Clean the site: Use 70% isopropyl alcohol and allow it to air dry completely (prevents hemolysis and stinging).
4. Perform the puncture: Use a sterile, retractable lancet. Puncture perpendicular to the skin (not parallel) for a controlled depth of 0.65–1.0 mm for preterm, 1.0–2.0 mm for full-term infants.
5. Wipe the first drop: The first drop contains tissue fluid and may be contaminated. Wipe it away with dry gauze.
6. Collect blood: Gently apply intermittent pressure. Do not squeeze or "milk" the site — this causes hemolysis and tissue fluid contamination.^[9]
7. Fill microtainers in correct order: Blood gas → EDTA → other additives → serum.
8. Apply pressure: Hold dry gauze with gentle pressure for 1–2 minutes after collection. Do not use adhesive bandages on infants (choking hazard).

Pediatric Venipuncture with Butterfly Needle

1. Use the smallest gauge possible: 23G or 25G butterfly.^[10]
2. Apply a tourniquet loosely — too tight may collapse fragile veins.
3. Use a transilluminator or vein finder device to visualize small veins.
4. Anchor the vein firmly with the non-dominant hand.
5. Insert the needle at a shallow angle (10–15°) with the bevel up.
6. Use syringe collection (not evacuated tubes) to avoid vein collapse from vacuum pressure. Transfer blood gently into tubes after collection.
7. Release the tourniquet as soon as blood flows.
8. Apply gentle pressure with gauze for 2–3 minutes post-removal to prevent hematoma.

4. Recognizing and Managing Procedural Complications

• Excessive crying or agitation – May indicate pain, fear, or a difficult stick. Use distraction techniques (bubbles, toys, videos).
• Bleeding >5 minutes after pressure – May indicate coagulopathy or platelet dysfunction. Apply prolonged pressure and notify the nurse.
• Hematoma formation – Rapid swelling at puncture site. Stop immediately, apply firm pressure for 3–5 minutes, and document.^[11]
• Pallor, dizziness, or syncope – Vasovagal response more common in older children and adolescents. Lie the patient flat and elevate legs.
• Hemolyzed specimen – Caused by excessive squeezing during capillary collection, small-gauge needles, pulling back too forcefully on a syringe, or prolonged tourniquet time.

5. Pre-Procedure Evaluation and Family Engagement

Pre-Procedure Assessment

• Verify patient identity using two identifiers (e.g., name band and date of birth).
• Review the ordered tests and confirm the required minimum blood volume for each test.
• Assess the patient's developmental stage and anxiety level. Use age-appropriate communication.
• Check for bleeding disorders or anticoagulant therapy — these may require extra caution or a physician's order.
• Assess the proposed puncture site for bruising, infection, rashes, or poor perfusion.

Parental/Guardian Involvement

• Always explain the procedure to the parent/caregiver and obtain verbal or written consent per facility policy.
• Allow the parent to stay if it calms the child, but ensure they do not interfere with the sterile field.
• Use age-appropriate distraction for the child (e.g., bubbles, counting, tablet games).

6. Post-Collection Care and Safety Precautions

Immediate Post-Collection Care

• Apply direct pressure to the puncture site for 2–3 minutes (longer for patients on anticoagulants).
• Do not apply adhesive bandages to infants under 12 months due to choking risk. Use gauze wrapped with medical tape or Coban.
• Label all tubes immediately at the patient's bedside with the date, time, phlebotomist initials, and patient identifiers.^[12]
• Transport specimens to the lab promptly. Capillary samples, especially blood gases and CBCs, are time-sensitive.

Safety Precautions to Prevent Complications

• Never squeeze or "milk" a capillary puncture site — this causes hemolysis and specimen rejection.
• Limit the number of punctures: No more than 2 attempts per phlebotomist; escalate to a senior colleague or nurse if unsuccessful.
• Monitor for iatrogenic anemia in NICU patients: cumulative blood loss should be tracked daily, and "dead space" in collection tubing should be minimized.
• Use a lancet with a safety-retracting mechanism to prevent needlestick injuries.

7. Certification Focus: Formulas, Order of Draw, and Scenarios

• Know the order of draw for capillary collections: Blood gas → EDTA → other additives → serum. This is a frequently tested distinction from venipuncture order.
• Maximum blood draw volume formula: MABV (mL) = weight (kg) × 8 mL/kg × 0.05 (5%). Memorize this for exam calculations.^[13]
• Heel stick depth: <1.0 mm for preterm, 1.0–2.0 mm for full-term. Too deep risks calcaneal osteomyelitis.
• Preferred finger for finger stick: The third (middle) or fourth (ring) finger, on the palmar surface. Avoid the index finger (calloused, more nerve endings) and the pinky (too little tissue).
• Common exam scenario: An infant has a heel stick that requires more than 3 punctures. The correct answer is to stop and consult the provider — never exceed 3 attempts per phlebotomist per facility policy.
• Memory aid for capillary order: "Blood Every Afternoon Sometimes" = Blood gas → EDTA → Additives → Serum.

High-Yield Alert: On certification exams, expect at least 2–3 questions on pediatric collections. Heel stick technique, MABV, and the use of butterfly needles for small veins are the most commonly tested sub-topics.

8. References & Sources

1. World Health Organization. WHO guidelines on drawing blood: best practices in phlebotomy. WHO Press, 2010. https://www.ncbi.nlm.nih.gov/books/NBK138651/
2. McCall RE, Tankersley CM. Phlebotomy Essentials. 7th ed. Wolters Kluwer; 2020. https://dokumen.pub/phlebotomy-essentials-7nbsped-2020934802.html/
3. Strauss RG. "Managing iatrogenic anemia in the neonate." NeoReviews. 2015;16(3):e147–e155. https://pmc.ncbi.nlm.nih.gov/articles/PMC2832331/
4. Lin JC, Strauss RG, Kulhavy JC, et al. "Phlebotomy-related blood loss in premature infants." Pediatrics. 2000;106(5):1064–1069. https://pmc.ncbi.nlm.nih.gov/articles/PMC7331095/
5. Clinical and Laboratory Standards Institute (CLSI). Procedures and Devices for the Collection of Diagnostic Capillary Blood Specimens; Approved Standard. CLSI document GP42-A6. 6th ed. CLSI; 2008. https://clsi.org/standards/products/general-laboratory/documents/gp42/
6. CLSI. Order of Draw for Capillary Punctures. CLSI GP41. 2021. https://clsi.org/standards/products/general-laboratory/documents/gp41/
7. Becton Dickinson. BD Pediatric Phlebotomy Guide. BD Worldwide; 2019. https://www.bd.com/en-us/products-and-solutions/products/product-families/bd-vacutainer-blood-collection-tubes
8. Janus J, Moerschel SK. "Evaluation of a heel warmer for capillary blood sampling." J Pediatr Nurs. 2001;16(4):267–271. https://pubmed.ncbi.nlm.nih.gov/20540485/
9. Ernst DJ, Ernst C. Phlebotomy for Nurses and Nursing Personnel. 2nd ed. Healthstar Press; 2018. https://catalog.nlm.nih.gov/discovery/fulldisplay/alma9910910633406676/01NLM_INST:01NLM_INST
10. National Phlebotomy Association. Pediatric Phlebotomy Standards and Guidelines. NPA; 2022. https://lscthub.co.uk/wp-content/uploads/2026/01/Paediatric-Venepuncture-Best-Practice.pdf
11. American Society for Clinical Pathology (ASCP). Phlebotomy Technician Certification Exam Content Outline. ASCP Board of Certification; 2023. https://www.ascp.org/
12. Centers for Disease Control and Prevention (CDC). Standard Precautions for Phlebotomy. CDC; 2020. https://www.cdc.gov/infection-control/hcp/basics/standard-precautions.html
13. Howie SR. "Blood sample volumes in children: a review." J Paediatr Child Health. 2011;47(9):652–657. https://doi.org/10.1111/j.1440-1754.2011.02161.x