Specimen Collection: Blood Collection by Finger Puncture and Heel Stick RL.04.02 Michigan Regional Laboratory System May 2008
Specimen Collection: Blood Collection by Finger Puncture
I. Purpose:
To obtain an adequate blood specimen for laboratory tests through a skin puncture. Skin puncture blood is a mixture of undetermined proportions of blood from arterioles, venules, capillaries, and interstitial and intracellular fluids. The arterial portion can be increased by warming the site prior to collection. This increases the blood flow as much as sevenfold.
II. Materials And Equipment:
A. Disposable latex gloves (Use non-latex, e.g. nitrile or vinyl, if the employee and/or client has a latex allergy).
B. Isopropyl alcohol
C. Gauze
D. Blood lancets for skin puncture
E. Sharp’s containers
F. Band Aids (optional)
G. Appropriate microcuvettes, or tubes for micro sampling
H. Disinfectant (10% household bleach) for bench tops
I. Other personal protective equipment, e.g., lab coat or face shield, if appropriate
III. Safety:
A. Use Standard (universal) precautions as outlined in the Bloodborne Pathogen Plan.
B. Place sharp’s container close to the collection site.
C. Wear disposable gloves at all times during the procedure, and lab coat and other appropriate personal protective equipment as indicated.
D. Wash your hands before you put on your gloves and again after you remove and discard your gloves. Hand disinfectant gels are acceptable unless your department directives state otherwise or your hands are visibly soiled.
E. Change gloves between patients.
IV. Procedure:
A. Correctly identify and reassure the patient. Explain the procedure to the patient.
B. According to the NCCLS document, “Recommendations for Puncture Sites for Whole Blood Samples” the third or fourth (middle or ring) finger is used to obtain a sample. Choose a site that is on the side of the fingertip, midway between the edge and midpoint of the fingertip. Thoroughly wash hands with warm soapy water.
Specimen Collection: Blood by Finger Puncture
C. Thoroughly cleanse the chosen site with 70% alcohol. Wipe excess alcohol with sterile gauze. Allow the skin to air-dry. Wet alcohol remaining on the skin will sting the client and may dilute the sample.
D. Peform finger puncture across the fingerprints as the blood will more likely bead rather than run down the “channels” of the fingerprints. Also, the puncture devices (the depth) are designed to be used in this manner.
E. Use a sterile, OSHA approved, blood lancet to make a deep puncture (1.5 mm) at the chosen site. (A deep puncture is no more painful that a superficial one, gives a much better flow, and makes it unnecessary to repeat the procedure.) Immediately dispose of contaminated lancet into a sharp’s container.
F. Using a dry gauze, wipe away the first drop of blood, making certain the area is completely dry.
F.G. Apply moderate pressure, approximately 1 cm behind the site of the puncture to obtain a drop of blood. Do not ‘milk’ the finger!
G.H. Release this pressure immediately to allow recirculation of the blood.
H.I. Repeat steps G & H until enough blood has been collected.
I.J. Apply a piece of gauze, (or cotton ball), to the puncture site, using slight pressure until the bleeding has stopped. For adult patients, offer a band-aid.
V. References:
A. (NCCLS. Procedures and Devices for the Collection of Diagnostic Blood Specimens by Skin Puncture;Approved Standard Fifth Edition. NCCLS document H4-A4 [ISBN 1-56238-382-5]. Cllinical Laboratory Standards Institute, 940West Valley Road, Suite 1400, Wayne, Pennsylvania 19087 USA, 1999.)
B.
B. Brown, Barbara, 1980. Hematology: Principles and Procedures. Third Edition. Lea & Febiger. Philadelphia, PA.
