Basic Phlebotomy or Venipuncture - Blood Collection Guide

How To Collect Venous Blood

Healthcare facilities provide a comprehensive training for collection of blood specimen. Here are the basic steps that are necessary guide to collect a blood sample.

1. Observe standard precautions . If latex allergy is suspected, use latex-free supplies and equipment.
2. Position and tighten a tourniquet on the upper arm to produce venous congestion.
3. Ask the patient to close the fist in the designated arm. Select an accessible vein.
4. Cleanse the puncture site and dry it properly with sterile gauze. Povidone-iodine must dry thoroughly.
5. Puncture the vein according to accepted technique. Usually, for an adult, anything smaller than a 21-gauge needle might make blood withdrawal more difficult. A Vacutainer system syringe or butterfly system may be used.
6. Once the vein has been entered by the collecting needle, blood will fill the attached vacuum tubes automatically because of negative pressure within the collection tube.
7. Remove the tourniquet before removing the needle from the puncture site or bruising will occur.
8. Remove needle. Apply pressure and sterile dressing strip to site.

Note:

• The preservative or anticoagulant added to the collection tube depends on the test ordered.
• If your're a Medical Laboratory Scientists or Phlebotomist and doing a venipuncture for a patient admitted in a hospital, ask the nurse in charge first for some site restrictions such as those veins with fistula or check the patient's room for some important notes before collecting the blood. These are common to ICU patients.

After blood blood collection, explain to the patient the following:

• The tourniquet may feel tight.
• The patient may feel a pinch or nothing at all when the needle is inserted into the vein.
• There might be a small bruise at the site. Keeping pressure on the site reduces the chance of bruising.
• Taking anticoagulants (aspirin, Coumadin) may require keeping pressure on the site for more than 10 minutes to stop the bleeding. 
• The vein may become swollen after the test (phlebitis). The patient should call their healthcare provider and apply a warm compress to reduce the swelling.

How to Collect Blood from a Heel Stick 

Several drops of blood are collected from the heel of a baby.

1. Clean the heel with alcohol.
2. Puncture the heel with a small sterile lancer.
3. Collect several drops of blood in a small test tube.
4. Place a gauze pad over the site.
5. Maintain pressure until bleeding stops.
6. Apply a small bandage.

After the collection, explain to the parents or guardians the following:

• That the patient may feel a pinch or nothing at all when the lancer punctures the skin.
• There will be a bandage on the site for a short-time period. 
• That a small bruise might appear at the site.

How to Collect Blood from a Finger Stick

Several drops of blood are collected from the finger:

1. Clean the finger with alcohol.
2. Puncture the finger with a small sterile lancer.
3. Collect several drops in a small test tube.
4. Place a gauze pad over the site.
5. Maintain pressure until bleeding stops.
6. Apply a small bandage.

After collecting blood, explain to the patient the following:

• That the patient may feel a pinch or nothing at all when the lancer punctures the skin.
• There will be a bandage on the site for a short-time period. 
• A small bruise might appear at the site.