Capillary Blood Collection for Metabolic Testing
The collection of these specimens requires the same attention to detail as with any phlebotomy procedure.
- Gather all necessary equipment
Be certain to choose a device that punctures the heel to a depth appropriate to the size of the infant. Only use the filter cards provided by your state to collect the specimen. These cards are calibrated to the exact specifications needed for testing of metabolic disorders. An alternate or homemade card must not be used.
- Put on all necessary personal protective equipment
Gloves are always required. Gowns and eye protection may also be required.
- Positively identify the patient
Use two identifiers. The infant who is in the nursery should have an identification band attached to the ankle or wrist. In special care nurseries an alternate form of identification may be used. However, a crib card should never be used as a form of identification. Follow the practice for your facility.
Be certain that the heel can be easily accessed. Follow all nursery requirements that apply to safe handling of newborns.
- Warm the heel using an approved warming device
- Clean the site with alcohol or the approved disinfectant.
Allow the site to air dry before proceeding with collection of the specimen.
- Grasp the heel firmly but not tightly, activate the puncture device, wipe away the first drop of blood, and begin collection of the specimen.
Allow the blood to wick onto the card. Completely saturate the circle with one continuous drop of blood. Avoid touching the card to the skin. Apply the blood only to one side of the card. Do not layer the blood by applying a second drop on top of the first.
- Repeat the procedure to completely fill each circle on the card.
Each circle should be completely and uniformly saturated as shown in the bottom image on the right. Follow the policy of your institution or state to determine how many circles must be completely filled.
- Apply pressure to the puncture site using a sterile gauze
Gently raising the infant's leg above the level of the heart will also aid in clotting the puncture site. Bandage according to site-specific policy.
