Methods of Blood Collection (P) Flashcards
What are the equipment needed for blood collection?
1) Cotton balls
2) 70% isopropyl alcohol
3) Disposable lancet
4) Tourniquet
5) Syringe with needle
6) Adaptor
7) Two-way needle
8) Evacuated tubes (assorted)
What are the different methods of blood collection?
1) Skin Puncture (Adults)
2) Skin Puncture (Infants)
3) Venipuncture (Syringe Method)
4) Syringe Method (Evacuated Tube Method)
Where is sx. obtained from adults (skin puncture)?
From the tips of 3rd or 4th finger
Earlobe
How to collect sx. from adults via skin puncture?
1) Wipe the area with a cotton ball soaked in 70% isopropyl alcohol
2) Allow the site to air-dry or pat-dry with a sterile cotton
3) Puncture the preferred site with a sterile lancet. The puncture is ideally 2-3mm in depth
4) Wipe off the first drop of blood and collect the subsequent drops. Avoid squeezing the puncture site, as this will alter the composition of the blood
How to make withdrawal of sample (skin puncture) easier?
Put warm compress on the site
What are the sites for sx. collection for infants (skin puncture)?
Heel or big toe
How to collect sx. from infants via skin puncture?
1) Hold the baby’s foot firmly between the thumb and the index finger of your (the phlebotomist’s) non-working hand
2) Puncture the anterior rim of the posterior aspect of the heel or big toe only after a suitable preparation
3) Follow steps 1-4 for skin puncture for adults.
What is the recommended site for skin puncture on newborns?
Heel only
What is the site of collection for venipuncture (syringe method)?
Sx. is obtained from the veins in the antecubital fossa
How to collect sx. from adults via venipuncture (syringe method)?
1) Apply the tourniquet 3-4 inches above the puncture site in a half-knot manner to congest the vein. Ask the patient to open and close the hand several times
2) Cleanse the puncture site with 70% isopropyl alcohol. Allow the site to air dry. Puncture the vein with a sterile 21–23-gauge needle attached to a syringe at a 15 degrees angle and a depth of about 0.5-1cm
3) Loosen the tourniquet and gently aspirate the blood
4) After obtaining the required quantity of blood, place sterile gauze or cotton over the puncture site then withdraw the needle. Apply pressure to stop bleeding. Never flex the arm
Note: If bleeding is not arrested, elevate the arm and apply more pressure. Stay with the patient until the bleeding stops
5) Detach the needle from the syringe and transfer the blood along the side of an appropriate test tube. If the tube is anticoagulated, mix the tube with blood by gentle inversion
How to collect sx. from adults via venipuncture (evacuated tube method)?
1) Attached the two-way needle to adaptor. Prepare the evacuated tubes
2) Apply the tourniquet 3-4 inches above the site of puncture
3) Cleanse the site with 70% isopropyl alcohol. Allow the site to dry. Puncture the vein with the two-way needle attached to the adaptor. Push the tube into the adaptor until the other side of the needle penetrates the evacuated tube, making sure that the needle remains in position in the vein
4) Loosen the tourniquet and withdraw the needle when the blood has filled the tube to its proper volume
5) Gently invert the tube several times for proper mixing if the tube is anticoagulated
Note: For multiple blood draws, remove tube from the adaptor without withdrawing the needle and push the succeeding tubes into the adaptor
How to prevent hemolysis in skin puncture?
1) Use a sharp lancet
2) Avoid squeezing the area near the site
How to prevent hemolysis in venipuncture?
1) Use as sharp, smooth needle
2) Penetrate the uppermost wall of the vein fully
3) Check and make sure the tourniquet is not too tight when aspirating blood
4) Aspirate the blood gently
5) Remove the needle before transferring the blood to tubes (syringe method)
6) Mix the tube by gentle inversion if the tubes contains additives
7) If serum is needed, do not rim and centrifuge the blood until a clot has formed
