PMLS#17

• DERMAL (capillary or skin) PUNCTURE - Method of choice for collecting blood from infants and children younger than 2 years
• Drawing excessive amounts of blood from premature and small infants can rapidly cause IATROGENIC ANEMIA
• Excessive squeezing of the puncture site "milking"
• CAPILLARY BLOOD is a mixture of arterial venous blood and may contain small amounts of interstitial and intracellular fluids.
• • HIGH Glucose
  • LOW Total protein, Potassium, and Calcium
• LANCETS

  • are fine, sharply pointed needles used to prick the skin
  • recommended depth is 2mm and width is 2.5mm
• CAPILLARY TUBES/MICROHEMATOCRIT TUBES - small tubes used to collect approximately 50 to 75 µL of blood for the primary purpose of performing a microhematocrit test

  • RED BAND for heparinized tube
  • BLUE BAND for plain tubes
• MICROCOLLECTION TUBES/MICROTAINER - provide a larger collection volume and present no danger from broken glass

  • Microtainer tubes are designed to hold approximately 600 µL of blood
• PHLEBOTOMIST PREPARATION

  • the phlebotomist must have a requisition form
  • collection via dermal puncture must be on the requisition form
  • carefully examine the information on the requisition form
  • observe specific protective isolation procdures
• PATIENT IDENTIFICATION AND PREPARATION

  • Patients for dermal puncture must be identified (requisition form, verbal identification, and ID band)
  • In the nursery, an identification band must present on the infant and not just on the bassinet
• PATIENT POSITION

  • Must be seated or lying down with the hand supported on a firm surface, palm up, and fingers pointed for fingerstick
  • For heelsticks, infants should be lying on the back with the heel in a downward position
• SITE COLLECTION

  • (Infants younger than 1 y/o) Primary dermal puncture sites are the medial and lateral areas of the plantar (bottom) surface of the heel.
  • (1 y/o & Adults) Near the center of the third and fourth fingers on the palmar side of the nondominant hand are the sites of choice for finger puncture
• WARMING THE SITE

  • Moisten a towel with warm water (42°C) or activating a commercial heel warmer and covering the site for 3 to 5 minutes effectively warms the site
• CLEANSING THE SITE

  • Selected site is cleansed with 70% isopropyl alcohol, using a circular motion
• Heel puncture - is held between the thumb and index finger nondominant hand, with the index finger held over the heel and the thumb below the heel
• Finger puncture - is held between the nondominant thumb and index finger, with the palmar surface facing up the finger pointing downward to increase blood flow
• Puncture device position

  • The blade of the puncture device should be aligned to cut across(perpendicular to) the grooves of the fingertip or heel print
• Puncture device disposal

  • puncture device should be placed in an appropriate sharp's container
  • a new puncture device must be used if an additional puncture is required
• Sample collection

  • Wipe the first drop of blood with gauze to prevent contamination with tissue fluids and residual alcohol
  • Do not "milk" the side; blood should be freely flowing
• Order of Collection

  • Capillary blood gases
  • Blood smear
  • EDTA tubes
  • Other anticoagulated tubes
  • Serum tubes
• Bandaging the patient

  • pressure applied to the puncture site with gauze
  • the finger or heel is elevated and pressure is applied until the bleeding stops
  • confirm that bleeding has stopped before removing pressure
  • do not use bandage for children younger than 2 yo
• Labeling the sample - Microsamples must be labeled with the same information required for venipunctures samples
• The calcaneus is a bone located in the...


  heel