Finger site selection
- Use the middle OR ring fingers where possible1,2 †
- The side of the ball of the finger is the recommended location1,2
- Puncture across the lines of the fingerprint, not parallel to them1,2 §
EXPERT TIP
These materials have been produced in consultation with key opinion leaders and follow global guidelines, but the user should use his or her professional judgement when using any technique or method described in these materials and should take into account all applicable national, regional and institutional guidelines and regulations.
1. WHO guidelines on drawing blood: best practices in phlebotomy. World Health Organisation; 2010.
2. Clinical and Laboratory Standards Institute (CLSI) document GP42-A6 (former H04-A6): Procedures and Devices for the Collection of Diagnostic Capillary Blood Specimens; Approved Standard – Sixth Edition. Clinical and Laboratory Standards Institute; Wayne, Pennsylvania, USA: 2008. * Weighing more than 10kg1 † Avoid the thumb and index finger because of calluses, and avoid the little finger because the tissue is thin2§ A parallel puncture may cause the blood to travel along the channels formed by the lines of the fingerprint, preventing drop formation2.
Collection procedure for finger samples
- After puncturing the skin, use a clean gauze to wipe away the first drop of blood to avoid specimen dilution with interstitial fluid1,2 (test dependent)
- With the patient’s hand pointing downward, firmly grasp the finger towards the base with your thumb placed along the length of the patient’s finger
- Gently massage along the length of the finger towards the tip, using a light squeeze-and- release motion to allow large droplets of blood to form and encourage continuous blood flow2
- If using a blood collection tube, place it vertically beneath the puncture site, and allow droplets to flow freely into the tube using gravity (A). Allow the next drop to form and drip into the container. Repeat until the tube is filled to the level required for testing; over-filling or under- filling may lead to inaccurate results2
- Attach the top of the specimen tube/container and gently mix the contents by swirling and inverting (gently turning upside down)
- If using a capillary tube or pipette allow a large drop of blood to form, position the device horizontally, and lightly touch the drop of blood (avoid touching the skin); allow the blood drop to be drawn into the collection vessel by capillary action (B) (avoid air bubbles)
EXPERT TIP
These materials have been produced in consultation with key opinion leaders and follow global guidelines, but the user should use his or her professional judgement when using any technique or method described in these materials and should take into account all applicable national, regional and institutional guidelines and regulations.
1. WHO guidelines on drawing blood: best practices in phlebotomy. World Health Organisation; 2010.
2. Clinical and Laboratory Standards Institute (CLSI) document GP42-A6 (former H04-A6): Procedures and Devices for the Collection of Diagnostic Capillary Blood Specimens; Approved Standard – Sixth Edition. Clinical and Laboratory Standards Institute; Wayne, Pennsylvania, USA: 2008.
The advantages of safety lancets over non-retractable devices for healthcare professional use
- The needle retracts automatically and permanently into the safety lancet after use, avoiding the risk of sharps injuries
- Safety lancets are designed for single use, avoiding the risk of cross-infection between patients
- Each safety lancet is designed to puncture and penetrate to a predetermined depth that is safe and specific to patient type
EXPERT TIP
These materials have been produced in consultation with key opinion leaders and follow global guidelines, but the user should use his or her professional judgement when using any technique or method described in these materials and should take into account all applicable national, regional and institutional guidelines and regulations.
1. Clinical and Laboratory Standards Institute (CLSI) document GP42-A6 (former H04-A6): Procedures and Devices for the Collection of Diagnostic Capillary Blood Specimens; Approved Standard – Sixth Edition. Clinical and Laboratory Standards Institute; Wayne, Pennsylvania, USA: 2008.
Selecting device puncture depth for finger puncture
- 2.2mm is the maximum puncture depth that should typically be used for finger puncture in adults and children over eight years old1
- Depths of up to 2.2mm should be used in proportion to body size and weight†
- Recommended maximum puncture depth for children between six months* and eight years old is 1.5mm1
- Babies under six months old, weighing less than 10kg, or not yet walking should be punctured on the heel1
EXPERT TIP
These materials have been produced in consultation with key opinion leaders and follow global guidelines, but the user should use his or her professional judgement when using any technique or method described in these materials and should take into account all applicable national, regional and institutional guidelines and regulations.
1. WHO guidelines on drawing blood: best practices in phlebotomy. World Health Organisation; 2010. * Weighing more than 10kg1 † Generally, shorter lancets for patients with lower body weight than average, and longer lancets for patients with above-average weight for age.
Preparation procedure prior to finger puncture
- Consult institutional guidelines for specific information on the type of test being performed
- Gather all the equipment needed which may include gloves, alcohol pads, clean gauze, safety lancets, bandages, test strips, pipettes or other capillary blood collection tubes and a biohazard sharps container
- Identify the patient according to patient safety standards, which requires asking a minimum of two unique questions such as name, date of birth and/or address
- Consider warming the puncture site to facilitate blood flow when the site is cold or if a larger blood volume is required for testing
- Warming techniques may include asking the patient to rub their hands together or wash their hands in lukewarm water, or covering the puncture site with a warming device (commercial device or a warm, moist towel for 3-5 minutes) not to exceed a maximum temperature of 42°C or 107°F1
- The patient should be sitting or lying down with the hand pointing downward to encourage blood flow via gravity
- Disinfect the site according to institutional guidelines. If alcohol is used, ensure it has completely air-dried before puncture (do not wipe the site dry). This will help to avoid haemolysis of the specimen which may cause inaccurate results and/or the need to re-collect the specimen1,2
- Preparation of the site is now complete and ready for puncture and sampling
EXPERT TIP
These materials have been produced in consultation with key opinion leaders and follow global guidelines, but the user should use his or her professional judgement when using any technique or method described in these materials and should take into account all applicable national, regional and institutional guidelines and regulations.