MaineMedicalCenter June 2000

Portland, Maine

BLOOD COLLECTION BY FINGER STICK CAPILLARY PUNCTURE

INTRODUCTION:

Although the need for an accurate and precise method in point-of-care (bedside) testing is emphasized, little attention has been devoted to establishing quality control procedures for collecting and handling a blood specimen. Proper specimen collection and handling are of the utmost importance because errors are more likely to occur in these areas than during the POCT procedure itself.

Collection errors encompass incorrect identification of the patient specimen, hemolyzed blood specimens, and use of an incorrect anticoagulant during specimen collection. Studies show that 8% of errors in patient name, age, gender, and identification numbers are undetected despite extensive manual checking procedures. Clerical errors are difficult to detect and control systematically. National standards for proper specimen collection have alleviated many of these problems.

PRINCIPLE:

The capillary procedure involves puncturing a finger with a lancet to obtain a capillary blood specimen. Not all tests can be performed using the capillary method because of the volume requirements of those tests. A thorough understanding of the technique involved and a constant awareness of the patient are paramount.

MATERIALS:

Alcohol prep pad

Gauze sponge

Lancet device

Testing materials

Adhesive bandage

THREE TYPES OF SURESOFT LANCETS:

  • Light blue color-coded SureSoft Gentle lancets(Meditech No. 008985) are light penetration lancets used for fingerstick punctures with infants, children, and patients with very soft fingertips.
  • Deep blue color-coded SureSoft Regular lancets(Meditech No. 008984) are deep penetration lancets and are used with adults and are never used with infants.
  • Yellow color-coded SureSoft Dual heelstick lancets(Meditech No. 010574) are used with infant heelstick capillary collections only.

NOTE: Under no circumstances should a Tenderfoot device or yellow color-coded SureSoft Dual Lancet be used for a finger stick.

FINGERSTICK CAPILLARY PUNCTURE PROCEDURE SUMMARY:

The capillary puncture procedure is complex and requires both knowledge and skill. The trained phlebotomist must execute the following basic steps when drawing a blood specimen:

  1. Confirm the identify of the patient
  2. Verify patient diet restrictions
  3. Gather materials
  4. Reassure the patient
  5. Position the patient comfortably
  6. Verify paperwork, if any
  7. Wash your hands and don a comfortable pair of exam gloves
  8. Select the puncture site
  9. Cleanse the puncture site
  10. Perform the capillary puncture and collect the specimen
  11. Place gauze over the puncture and apply mild pressure
  12. Bandage the puncture site (optional)
  13. Dispose of the lancet into a SHARPS receptacle
  14. Eliminate the diet restrictions
  15. Process/test the specimen

FINGERSTICK CAPILLARY PUNCTURE PROCEDURE:

1. CONFIRM THE IDENTIFY OF THE PATIENT

Identification of the patient is crucial. You must ensure that the blood specimen is being collected from the individual designated.

NEVER ASSUME ANYTHING

2. VERIFY PATIENT DIET RESTRICTIONS

Some tests require the patient to fast and/or eliminate certain foods from the diet prior to the blood drawing. Time and diet restrictions vary according to the test. Such restrictions are necessary to ensure accurate test results.

3.GATHER MATERIALS

  • alcohol prep pads
  • gauze sponges
  • lancet device
  • testing materials (e.g., glucose meter and test strip)

4.REASSURE THE PATIENT

It's always a great idea to introduce yourself and explain the procedure to the patient. Assure the patient that, although the capillary puncture will be slightly painful, it will be of short duration.

5.POSITION THE PATIENT COMFORTABLY

FINGERSTICK CAPILLARY PUNCTURE PROCEDURE (CONTINUED):

6.VERIFY PAPERWORK, IF ANY

7.WASH YOUR HANDS AND DON A COMFORTABLE PAIR OF EXAM GLOVES

8.SELECT THE PUNCTURE SITE

(A)CHILD’S FINGER:

A capillary puncture must not be performed on the finger of an infant under the age of 1 year. The distance from the skin surface to bone in the thickest portion of the last segment of each finger varies from 1.2 to 2.2 mm, and most lancets penetrate deeper.

Follow the procedure as described below for the adult’s finger.

(B) ADULT’S FINGER:

Select the ring finger or the middle finger. The skin-puncture site should be warm and not swollen (edematous) because accumulated fluid in the tissues will contaminate the blood specimen. The puncture shall be on the palmar surface of the fingertip (fleshy pad) and not at the side or tip of the finger, where the tissue is about half as thick.

The thumb is to be avoided because it has a pulse. The index finger tends to be more calloused, which would make collection of the specimen more difficult. This area is also more sensitive for the patient. The pinky finger does not have sufficient tissue depth to prevent injury.

When performing a fingerstick, the phlebotomist should puncture either side of the fleshy pad of the middle or ring finger, but not the extreme side of the finger. The exact center of the fleshy pad or the tip of either finger should also be avoided. Avoid areas of the finger that are cold, swollen, inflamed, calloused or cyanotic.

The puncture should be made slightly off center from the central, fleshy portion of the fingertip and perpendicular (not parallel) to the fingertip whorls. Puncturing along or parallel to the whorls may cause the blood to follow the pattern of the fingerprint, making it more difficult to collect.

FINGERSTICK CAPILLARY PUNCTURE PROCEDURE (CONTINUED):

9.CLEANSE THE PUNCTURE SITE

Using an alcohol prep pad, cleanse the puncture site with a circular motion from the center to the periphery. Allow the area to AIR DRY COMPLETELY to prevent hemolysis of the specimen; hemolysis may cause erroneous test results.

10.PERFORM THE CAPILLARY PUNCTURE AND COLLECT THE SPECIMEN

Using an appropriate lancet device, puncture the site and apply GENTLE PRESSURE to the fingertip.

NOTE: Under no circumstances should a Tenderfoot device or yellow color-coded SureSoft Dual Lancet be used for a finger stick.

Wipe away the first drop of blood to avoid tissue fluid contamination. After wiping the first drop of blood, a second will form. Apply GENTLE PRESSURE and collect/test the specimen.

NOTE: Do not use excessive "milking" or massaging of the finger.

11.PLACE GAUZE OVER THE PUNCTURE AND APPLY MILD PRESSURE

Apply mild pressure over the puncture site with the gauze sponge until bleeding stops completely.

12.BANDAGE THE PUNCTURE SITE (OPTIONAL)

13.DISPOSE OF THE LANCET INTO A SHARPS RECEPTACLE

Dispose of lancet devices promptly into an appropriately labeled sharps disposal container to pre-vent their reuse or accidental injury. Do not allow the sharps container to become more than ¾ full.

14.ELIMINATE THE DIET RESTRICTIONS

15.PROCESS/TEST THE SPECIMEN


REVIEW SCHEDULE:

PREPARED BY: / Denis R. Netto, MT(ASCP)
Technical Consultant / June 26, 2000
Revised August 18, 2010
SUPERSEDES: / Collection of Blood by Fingerstick
Capillary Puncture / July 24, 2008
ADOPTED BY: / Timothy E. Hayes, DVM, MD
POCT Program Director / August 18, 2010
ADOPTED BY: / Michael A. Jones, MD
POCT Program Director / August 18, 2010
REVIEWED BY:
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SIGNATURES:

Authorized signatures, as well as periodic review records, are on file with the Maine Medical Center POCT Program Technical Consultant and/or the Maine Medical Partners Technical Consultant.

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