1. Capillary Puncture AKA: capillary, dermal or skin puncture
Useful for pediatric patients to avoid iatrogenic anemia

2. Capillary Puncture Equipment
Lancet
Sterile and disposable
Retractable blade
Either finger or heel
Micro-collection containers (microtubes)
Used to collect tiny amounts of blood
Microhematocrit tubes
Manual HCT
CBG collection tubes
Capillary blood gas specimens

3. Compositions of Capillary Specimens
Mixture of arterial, venous, and capillary blood plus interstitial fluid and intracellular fluid
Reference values different than venipuncture specimens
Potassium levels falsely elevated with tissue fluid contamination or hemolysis of specimen

4. Indications for Capillary Puncture
Micro volume to avoid anemia
Veins need to be reserved for chemotherapy
Patients with extensive burns
Patients that clot easily
Several unsuccessful venipunctures
Patients with blenophobia
No accessible veins
Infants and children
POCT testing: CBC, cholesterol & glucose screening

5. TESTS NOT DONE BY SKIN PUNCTURE
Blood cultures
Erythrocyte Sedimentation Rate
Coagulation studies
Tests requiring large volume of sera or plasma
Patients where capillary puncture is not appropriate:
Dehydrated patients
Patients with poor circulation to extremities from shock

6. Order of Draw Blood gas EDTA specimens (hematology)
Other additive specimens
Serum specimens

7. Site Selection Adults and children older than 1 year
Palmar surface of the end segment of the middle or ring finger
Use non-dominate hand
In central fleshy portion slightly to the side of center
Perpendicular to grooves of fingerprint
NEVER use fingers or earlobes of newborns or infants under 1 year!!

8. Site Selection Infants Do not to exceed 2.0 mm-
Puncturing of bone can lead to osteomyelitis
Stick perpendicular on the most medial or most lateral portion of the plantar surface of the heel
Calcaneous may be just 2 mm below skin
Warm site before puncture
Use warm water or heel warmer device
Do not exceed 42 degrees C

9. SKIN PUNCTURES Cleaning the site Always wipe away first drop of blood
70% isopropyl alcohol
Never use povidone-iodine as it interferes with some tests
Always wipe away first drop of blood
Contains fluid plasma, tissue extracts, and possibly alcohol residue
Do Not Squeeze (or “milk”) Site
Results in hemolysis & increased tissue fluid contamination
Do not use a “scooping” motion against the surface of the skin
Activates platelets causing them to clump
Can cause hemolysis

10. SKIN PUNCTURES Labeling of specimens: Patient name & ID number
Time & Date of collection
PBT initials

11. BLOOD GASES - NEONATES
Source of blood is from catheter in umbilical artery
Procedure is the responsibility of the pediatric unit or neonatal intensive care unit.

12. Neonatal Bilirubin Collections
Used to detect and monitor increased bilirubin levels in newborns
High levels result in jaundice
Breaks down in presence of light
Collected by heel stick
Must be protected from hemolysis and light
Use amber colored micro-collection container
Turn off UV lamp in crib

13. Newborn Screening Tests
Test for:
PKU-phenylketonuria-a genetic disorder
Hypothyroidism
Galactosemia
Cystic Fibrosis
Blood spot collection:
Heel stick blood collected by absorption onto 5 circles on a special paper
Paper must not touch heel
Blood must completely fill circles from one side of the paper only
Contaminants include: alcohol, formula, lotion, power, urine

14. BLOOD SMEARS Wipe away first drop of blood, make smear immediately.
EDTA Blood Tube:
Make blood smears within 1 hour of collection
May be stored at 4 degrees celsius (refrig.) overnight for CBC
For smears: hours after standing at room temperature.
Acceptable smear:
Blood covers half to three-fourths of the slide with a feathered edge
Has no holes, lines, or jagged edges

15. BLOOD SMEARS Smear fixative - methyl alcohol for 1 minute
Manual wedge - spreader/pusher slide; 30 degree angle
Spinner - automated cell counter