STEPS TO FOLLOW IN PERFORMING A VENIPUNCTURE
9. It is better to use syringes if veins are small. Winged collection sets (“butterflies”) are also available and useful if multiple tubes are needed. If a syringe is used, move the plunger up and down in the barrel once or twice to make sure it does not stick. Expel all air before proceeding. Do no remove the needle cap until immediately prior to the puncture.
10. Grasp the arm just below the site and pull the skin tight with the thumb.
11. Hold the syringe or Vacutainer assembly with the opposite hand. Rest the index finger on the hub of the needle as a guide. Other fingers will serve as a cushion for the syringe or Vacutainer and will help steady it.
12. Point the needle in the direction of the vein and in line with the vein. Hold it at an approximate 15 degree angle to the arm.
13. Enter the vein slightly below the area where it can be seen. This way, there is more tissue and this will anchor the needle. The bevel of the needle should be directed up. As the needle enters the vein, a “give” will be noted.
14. Filling of tubes–
a. If a syringe is used, blood will begin to flow as soon as the needle enters the vein. If using a syringe, do not pull back too hard on the plunger; this may hemolyze the cells, collapse the vein, or pull the wall of the vein over the bevel, stopping the blood flow. Keep the needle steady; do not push in or pull out. Continue pulling plunger back gently until enough blood is collected to fill all needed tubes.
b. If a Vacutainer is being used, as soon as the needle is in the vein, push the tube firmly but carefully into the holder centered onto the back end of the needle until a resistance is felt. If the vein has been located, blood flow will begin at the resistance point. Keep the needle steady. If collecting multiple samples, wait until the vacuum is exhausted and blood flow ceases. Gently remove the tube from the holder, keeping the needle steady, and place the next tube into the holder.
c. The proper order of draw is:
i. Blood culture bottles
ii. Red or blue if any coagulation tests other than PT/PTT ordered (invert 3-4 times)
iii. Blue top – must be at least 90% full (invert 3-4 times)
iv. Gold top (invert 5 times)
v. Red top (invert 5 times)
vi. Green top (invert 8-10 times)
vii. EDTA pink and/or purple (invert 8-10 times)
viii. Any other tubes
Remember to invert tubes gently after drawing to properly mix additive and blood.
NOTE: This same order should be used to fill tubes when a syringe is used to collect the sample. After collecting the sample, lock the safety device over the syringe needle. Carefully remove the used needle and attach a transfer device to the syringe. Using the same order as above, fill each tube. Allow the vacuum in the tube to pull the blood into the tube. Do not use the plunger to force the blood into the tube. This can lead to hemolysis. It can also cause excess pressure in the tube which could cause the stopper to pop off resulting in a blood splatter.