Policies,Clinical,UWHC Clinical,Department Specific,Clinical Laboratories

Skin Puncture Blood Collection (1507.P010)

Skin Puncture Blood Collection (1507.P010) - Policies, Clinical, UWHC Clinical, Department Specific, Clinical Laboratories


UWHC Clinical Laboratories Original Date: 2/28/98
Phlebotomy Current Version Date: 1/29/11
Document Title: Skin Puncture Blood Collection
Document ID: 1507.P010 Page 1 of 7

Medical Director: Dr Teresa Darcy, MD 2/26/13; David Yang, MD 5/24/17

Effective Date: 1/29/2011
Technical Reviewer Date Manager Date Faculty Director Date
Kim Corrado 2/15/11 Michael W. Baron 2/14/11 Teresa Darcy, MD 2/14/11
Tammy Colson 2/16/12 Michael W. Baron 2/16/12 Teresa Darcy, MD 2/16/16
Karin Ravet 2/26/13 Kimberly Corrado 2/26/13 Teresa Darcy, MD 2/26/13
Barbara J Powell 2/24/14 Kimberly Corrado 2/25/14 Teresa Darcy, MD 2/25/14
Sabra Abloviak 3/9/15 Kimberly Lueptow 3/2/2015 Teresa Darcy, MD 3/2/2015
Melissa Hahn 5/15/17 Kimberly Lueptow 6/7/17 David Yang, MD 5/24/17

I. Purpose or Principle
A. Provide a procedure to collect quality blood specimens by means of skin puncture.

II. Policy
A. Skin puncture is performed for the following reasons:
1. Requested by the physician in lieu of venous blood
2. Unable to obtain venous specimens
3. Preferred sample is capillary blood (e.g. capillary blood gas)
B. CAUTION: Gloves must be worn and “standard precautions” must be used for this
collection procedure to avoid exposure to blood.
C. Skin-puncture blood is a mixture of blood from artererioles, venules and capillaries and
contains interstitial and intracellular fluids.
D. The skin-puncture site must be warm. If the collection site is not warm, the area must be
pre-warmed before performing the procedure.
1. Warming the skin-puncture site will increase blood flow up to seven-fold, due to
increase in the arterial blood flow. Specimens from warmed sites are called
“arterialized skin-puncture blood” and are the preferred specimens for pH and blood
gas analysis. Five to ten minutes of warming is recommended when pH and blood
gas specimens are collected.
2. Warming should be performed with a manufactured warming pack.
E. The skin-puncture site must not be edematous (swollen) because accumulated fluid in
the tissue will contaminate the blood specimen.
F. If the patient is dehydrated or has poor peripheral circulation it may be impossible to
obtain a representative blood sample, especially by skin puncture.
G. The site is cleaned with 70% isopropanol and must be thoroughly dried with gauze. If
not dried, the alcohol causes rapid hemolysis and errors in blood glucose. Betadine
shall not be used to clean the site because it falsely elevates levels of potassium,
phosphorus and uric acid.
H. Skin-puncture blood can be obtained from the:
1. Lateral or medial plantar surface of the heel, never use plantar surface of the heel.
2. Plantar surface of a big toe.
3. Palmar surface of the distal phalanx of the third or fourth finger.
I. Skin-puncture of the earlobe is not recommended because of poor circulation.
J. The skin-puncture site most frequently used with older children and adults is the distal
lateral aspect of the fingertip.
1. The puncture is made on the palmer surface of the distal phalanx and not at the side
or tip of the finger because the tissue on the side and tip of the finger is about half as
thick as the tissue in the center of the finger.

UWHC Clinical Laboratories Original Date: 2/28/98
Phlebotomy Current Version Date: 1/29/11
Document Title: Skin Puncture Blood Collection
Document ID: 1507.P010 Page 2 of 7

2. The fifth finger is not punctured because the tissue is considerably thinner than the
tissue of the thumb, index, middle and ring fingers.

Skin-puncture site for older children and adults


Puncture the distal lateral The skin-puncture should be a quick,
aspect of the fingertip fingerprint. deep puncture across, not parallel.

K. Heel puncture is the preferred collection sites for infants less than one (1) year of age.
1. The heel puncture is performed on the plantar surface medial to a line drawn
posteriorly from the middle of the great toe to the heel or lateral to a line drawn
posteriorly from between the 4th and 5th toes to the heel.
2. Skin punctures will not be performed on the central area of an infant’s foot (arch)
because it may result in injury to nerves, tendons and cartilage.
3. The puncture shall not be through a previous puncture site or the curvature of the
4. Skin punctures shall not be performed on the fingers of infants because the distance
from skin surface to bone in the thickest portion of newborn infants varies from 1.2 to
2.2 mm. With use of lancets, the bone could easily be injured which may result in
possible local infection and gangrene.
5. Some crying and struggling is to be anticipated, however, it is important to calm the
child as soon as possible. Stress of crying and struggling can alter blood
components and lead to erroneous results.

Skin-puncture site for heel puncture

UWHC Clinical Laboratories Original Date: 2/28/98
Phlebotomy Current Version Date: 1/29/11
Document Title: Skin Puncture Blood Collection
Document ID: 1507.P010 Page 3 of 7

Bottom Back Side

6. Use the most medial or lateral portions of the plantar surface of the heel.
7. Do not use the posterior curvature of the heel.
8. Puncture should be no deeper than 2.0 mm.
9. Do not use previous puncture sites.
L. Single-use automatic, retractable skin-puncture devices (lancets) are used because they
provide a safe device to make consistent puncture depth to obtain adequate blood flow
without causing injury to newborn infants and adults. Example of an acceptable Safety
Flow Lancet is the Tenderfoot™ (pictured below):

1. The major blood vessels of the skin are located at the dermal-subcutaneous junction,
which in the newborn’s heel is 0.35 to 1.6 mm deep. A puncture 2.0 mm deep on the
plantar surface of the heel will penetrate the skin’s major vasculature and does not
risk puncture of the bone for small infants. Puncturing deeper than 2.0 mm on the
plantar surface of the heel of small infants may risk bone damage. The heel bone
(calcaneus) is less than 2.0 mm beneath the skin surface at the posterior curvature
of the heel.
2. Surgical blades MUST NOT be used to puncture skin because they may create a
wound much deeper than necessary.
3. When using puncture device, hold the heel or finger firmly to prevent sudden
M. Skin-puncture collection devices are available to collect specimens by:
1. Capillary action in capillary tubes.
2. Through the collector tops of micro-collection devices. This may be a capillary or a
small funnel type scoop. Drop-by-drop collection into small tubes is not allowed
because the mechanical trauma of pressing the tube on the skin may increase
3. Filter paper is used to collect drops of blood directly from the skin-puncture site.

UWHC Clinical Laboratories Original Date: 2/28/98
Phlebotomy Current Version Date: 1/29/11
Document Title: Skin Puncture Blood Collection
Document ID: 1507.P010 Page 4 of 7

N. Before collecting the blood sample, wipe the first drop of blood away with a gauze pad
because this drop is likely to contain excess tissue fluid. As the second drop of blood
forms over the site, touch the tip of a micro-collection device to the drop, the blood will
flow down the wall of the collection container. Blood flow is enhanced by holding the
puncture site downward and gently applying continuous pressure to the surrounding
tissue. Strong repetitive pressure (milking) should not be used, as this may cause
hemolysis or contamination of the specimen with tissue fluid. Scooping the blood up
from the surface of the skin should be avoided. Drops of blood should be allowed to flow
freely into the collector top and down the walls of the tube. If drop becomes lodged,
gently tap the tube to move it to the bottom of the tube. When collecting a microtainer,
the specimen must be mixed by inverting 8-10 times after closure. Give the tube one
quick shake, as if to shake down a thermometer, to remove excess blood from around
the bottom of the closure.
O. Examples of skin-puncture collection devices in use:
1. Heparin plastic capillary tubes

2. Microtainers

3. Wisconsin State Laboratory of Hygiene Newborn Screening Filter paper:

a. Information filled-out by ordering provider, e.g. gestational age in weeks, etc.
b. Obtain blank forms from Core Lab. Do not store extras in Phlebotomy Lab.

UWHC Clinical Laboratories Original Date: 2/28/98
Phlebotomy Current Version Date: 1/29/11
Document Title: Skin Puncture Blood Collection
Document ID: 1507.P010 Page 5 of 7

c. Allow to air dry 2-4 hours before transporting to lab.
d. Do not touch filter paper surface.
4. To collect blood for filter paper, allow a large blood drop to form and touch it to the
surface of the filter paper and observe the complete saturation of each circle.
a. FILL ALL CIRCLES. Examine both sides of the filter paper to assure the blood
penetrated and saturated the paper.
b. When using heparinized capillary tubes, use a fresh capillary tube for each circle
d. Circles must be completely filled when observed from both sides of the filter
5. If insufficient sample has been obtained, the puncture may be repeated at a different
site, using a fresh skin-puncture device. Never puncture a patient more than twice –
have another phlebotomist take over if you have tried and are unsuccessful two
6. After sample is obtained, apply pressure to puncture site. Correctly label all
specimen containers. Record the test was performed on skin-puncture blood and
whether or not the site was warmed before puncture.
7. Dispose of used supplies in appropriate containers.
8. The microtainer order of draw for skin puncture is different from venous order of draw
and is as follows:
a. EDTA (lavender) specimens
b. Additive specimens
c. Non-additive specimens
9. After blood is collected from an infant’s heel, the foot should be covered with gauze
and the foot should be elevated above the body until the bleeding stops. Do not
apply adhesive bandages over sites on children less than two years old. In infants,
adhesive bandages can cause irritation and an older infant may remove the
bandage, put it in his/her mouth and possibly aspirate it.
P. Equipment:
1. Gloves
2. Skin-puncture device or Tenderfoot™
3. Microtainer collection devices, plastic capillary tubes
4. Alcohol pads
5. Gauze sponges
6. Manufactured Infant heel warmer

III. Procedure
A. Identify the patient using two (2) patient identifiers.
B. Warming site for 3-5 minutes is recommended (5-10 minutes is recommended for pH
and blood gas collection).
C. Assemble equipment.
D. Wash hands and put on gloves.
E. Cleanse and completely dry the site.
F. Immobilize the finger or heel and perform the puncture.

Tenderfoot™ Puncture Device

UWHC Clinical Laboratories Original Date: 2/28/98
Phlebotomy Current Version Date: 1/29/11
Document Title: Skin Puncture Blood Collection
Document ID: 1507.P010 Page 6 of 7

Blue Safety Flow Lancet – finger puncture device

G. Wipe away the first drop of blood with dry gauze.
H. Use a squeeze and release technique to collect specimen.
I. To collect blood in plastic capillary tubes, hold the capillary tube at a 45° angle and use
the capillary action to fill the tube.

UWHC Clinical Laboratories Original Date: 2/28/98
Phlebotomy Current Version Date: 1/29/11
Document Title: Skin Puncture Blood Collection
Document ID: 1507.P010 Page 7 of 7

J. To collect blood in microtainer, hold tube at a 30° to 45° angle, touching collector end to
drop of blood. Blood will flow down the wall of the reservoir to bottom of tube. Mix
appropriately, and seal the container.

K. If blood runs down the heel instead of forming a drop, use a 2x2 gauze to wipe away the
excess blood. The next squeeze will reform the drop.

IV. Alternate and/or Down Time Procedure – Not used

V. Author and/or Revised by - Phlebotomy Manager

VI. References
A. Procedures for the Collection of Diagnostic Blood Specimens by Skin Puncture – Sixth
Edition March 2009, CLSI Document H04-A6, Vol. 28, No. 25.
B. Blood Collection of Filter Paper for Neonatal Screening Programs, Sixth Edition March
2009, CLSI Document LA4-A5, Vol. 28, No. 34.
C. Blood Gas and pH Analysis and Related Measurements; Approve Guidelines – Second
Edition, CLSI C46-A2, Vol. 29 No. 8.
D. Phlebotomy Handbook – Seventh Edition – Blood Collection Essentials. Diana Garza
and Kathleen Becam-McBride.
E. Capillary Blood Specimen Drawing, UWHC Nursing Care Policy 11.12, 04/01/2009.

VII. Review
A. Medical Director
B. Phlebotomy Manager
C. Phlebotomy Supervisor