SKIN PUNCTURE

• Skin puncture/Capillary puncture


  • Technique of choice to obtain a blood specimen from newborns and pediatric patients
  • Alternative collection when minute amount of blood is needed, and venipuncture is inadvisable for the adult patient
• Indications to perform skin puncture - Adults


  • Severely burned patients
  • Veins reserved for therapeutic purposes
  • Extremely obese patients
  • Elderly patients with fragile veins
  • Clotting tendencies
  • POCT procedures (glucose)
• Indications to perform skin puncture - Children/Infants


  • To prevent anemia
  • To prevent cardiac arrest from removal of large quantities of blood
  • Venipuncture too difficult
  • To prevent injury
  • When capillary blood is preferred
• Capillary blood


  • Mixture of blood from venules, arterioles, capillaries, and interstitial and intracellular fluids
  • When the puncture site is warmed, the specimen more closely resembles arterial blood
• Applications of capillary blood


  • Manual Hematocrit
  • RBS - Glucometer
  • Blood Smear
  • CBC/Cell Count
  • Newborn Screening
  • Some Serology Tests
• Tests that cannot be performed by capillary puncture


  • Erythrocyte Sedimentation Rate (ESR)
  • Coagulation studies that require plasma
  • Blood cultures
  • Tests that require large volumes of serum or plasma
• General criteria for puncture sites


  • Skin is warm and pink
  • No scars, cuts, bruises, rushes, cyanosis, etc.
• Preferred puncture sites


  • Lateral plantar heel for infants (<1 year old)
  • Fleshy portion of the phalanx of the 3rd or 4th finger of the non-dominant hand
  • Earlobe - obsolete
• Fingers of infants must be avoided
• Warming


  Increases blood flow sevenfold
• Puncture site must be cleaned with 70% Isopropyl Alcohol
• Povidone iodine must be avoided as it causes false increase in Potassium, Uric acid, or Phosphorus
• Precautions


  • Puncture site must be securely immobilized
  • Recommended depth of skin puncture: Infants and small children: <2 mm, Adults: 2.0 to 2.5 mm
  • First drop of blood should be wiped away with a clean gauze
  • Puncture should be perpendicular to the fingerprint
• Equipment


  • Lancet
  • Capillary tube
  • Microcollection Tube (Blood gas analysis tubes, Slides/glass slides, EDTA Microcollection tube, Other anticoagulated microcollection tubes, Serum, microcollection tubes)
• Procedure


  1. Review test request

  2. Approach, identify, and prepare patient

  3. Verify diet restriction and latex sensitivity

  4. Sanitize hands and put on gloves

  5. Position patient

  6. Select puncture/ incision site

  7. Warm site if applicable

  8. Cleanse and air-dry site

  9. Prepare equipment

  10. Puncture the site and discard lancet

  11. Wipe away first blood drop

  12. Fill and mix tubes/ containers in order of draw (if test requires use of microcollection tubes)

  13. Place gauze and apply pressure

  14. Label specimen and observe special handling instructions

  15. Check the site and apply bandage

  16. Dispose of used and contaminated materials

  17. Thank patient, remove gloves, and sanitize hands

  18. Transport specimen to lab
• Blood collection tubes are labeled according to their contents and color-coded for easy identification.
• The skin puncture procedure involves cleaning the area with an antiseptic solution, inserting a sterile needle into the vein or capillary bed, applying pressure to stop bleeding, and collecting the sample in a clean tube.
• Blood collection tubes are color-coded based on their contents.
• Skin puncture is often preferred for blood collection in infants and young children due to the smaller blood volume needed.
• The most common sites for skin puncture are the finger, heel, or earlobe.
• Skin puncture is the most common method used to collect blood samples.
• Skin puncture is a technique used to obtain capillary blood samples for testing.
• The skin puncture procedure involves cleaning the area with an antiseptic solution, inserting a sterile needle into the vein or capillary bed, applying pressure to stop bleeding, and collecting the sample in a tube containing an appropriate preservative.
• Skin punctures can cause pain, bruising, infection, hematoma formation, and nerve damage.
• Plain Red Top - No additive, used for serum separation
• The most common types of blood collection tubes include plain red top, lavender top, green top, blue top, yellow top, orange top, pink top, gray top, purple top, brown top, tan top, white top, and black top.