Venepuncture

Introduction Venepuncture is the term used for the procedure of entering a vein with a needle.

Indications

1. Withdrawal of blood for investigations
2. As a route for venous access

Procedure

1. Confirm patient identity   
2. Communicate with the patient
• Explain the procedure to the patient and get his/her verbal consent
• Try to minimize the patient distress
• Ask if blood has been withdrawn previously
• Sometimes the patient is able to point out sites where blood can be withdrawn successfully.
• Answer any questions the patient has  
3. Gather the equipment needed
• Non sterile pair of gloves
• Kidney tray
• Tourniquet
• Sterile alcohol swabs
• Sterile needle and syringe of an appropriate size
• Plaster / hypoallergenic tape
• Blood collecting tubes or bottles
• Ensure there is adequate light  
4. Select a site to puncture
• Potential sites

o Median cubital vein

o Median cephalic vein

o Basilic vein

o Cephalic vein

AVOID USING FOLLOWING SITES!

·         Any recently used sites might not be suitable for withdrawing

·         In limbs where an intravenous infusion is already placed

·         In bruised areas

·         In sites close to infection

·         On affected sides of patients with CVA or post mastectomy

 

5. Wash the hands and wear gloves    
6. Apply the tourniquet above the proposed site
• It should be tightened just enough for venous flow to be obliterated but not the arterial flow  
7. Make a vein prominent
• The arm must be well supported
• Ask the patient to clench a fist repeatedly to ensure more blood is pooled in the vein
• Palpate the vein to get a feel about the volume of blood in the vein
• A vein with a good volume of blood pooled in it would be firm and bouncy 
8. Clean the puncture site
• Use an alcohol swab
• Wipe in a spiral motion from inside to outside
• Allow the alcohol to dry on its own

o Pricking while the alcohol is still on, will be more uncomfortable to the patient

o Allowing alcohol to dry off lets the alcohol do its disinfectant function maximally

• Once the puncture site is cleaned do not touch the site again

    9. Prepare the syringe

• Take the syringe out of the pack
• Screw the needle tightly (not very) into the hub in the syringe. Do this even if the needle comes attached to the syringe, as it might not be fitted tight enough thus resulting in air bubbling into the blood sample during withdrawing
• Pull back and push in the plunger a few times

o It might be too tightly fitted inside the syringe, which may make withdrawal difficult

10. Anchor the vein
• By applying manual traction from your non dominant thumb a few centimeters below the proposed puncture site

o This is especially necessary in elderly patients as veins start to slip about while puncturing

11. Prick and withdraw the blood

• Insert the needle at an angle of approximately 30° to the skin with bevel facing up
• As soon as you see a flash back of blood in the needle hub, reduce the angle of insertion
• Make sure enough length of needle is in the vein
• Withdraw blood using one hand to pull back the plunger
12. Finishing withdrawing
• When adequate blood had been removed ask the patient to relax the hand and loosen the tourniquet
• Withdraw the syringe
• Place a cotton swab over the puncture site apply pressure

o Do not bend the puncture site (e.g. bending the arm if it’s cubital fossa). This increases the size of the puncture gape and causes more bleeding.

13. Transfer the sample to collecting tube
• Unscrew the needle by holding it at its hub
• Discarded the needle  immediately into the sharps bin

NEVER RECAP THE NEEDLE!

This increases the chance of accidental pricks

• Plush the plunger in gently and transfer blood to the container without spilling

NEVER TRANSFER BLOOD WITH THE NEEDLE STILL ON!
This may cause haemolysis and alter both haematological and biochemical parameters

• Close the lid of the container and invert the tube at least 6 times to make sure any content in the bottle is mixed well with the blood
• If multiple tubes are filled, fill those in following order

o Tubes with no additives

o Coagulation tubes

o Tubes with additives

• Label all tubes

   14. Disposing the waste

• Needle – Sharp bin
• Any blood stained items (syringe, swabs, gloves) – Contaminated waste bin
• Plastic wrappers – Black bin

Throughout the procedure observe the patient for signs of dizziness and fainting

Complications

Immediate

1. Blood is not coming
• You can try just one more time
• If you fail, call someone who is more experienced than you.
2. Double puncture
• This is when the needle pierces through the vessel at 2 different sites
• If this happens withdraw the needle and keep a swab over the puncture site and maintain adequate pressure to avoid the formation of a haematoma
3. Air bubbling into the blood sample
• Screwing the needle tight and keeping enough needle length into the vessel will prevent air bubbling to the syringe
• If the sample needs to be sterile, discard the sample
• If the sample need not be sterile, push in a bit more and try again
• If still bubbling, air might be coming from another prick on the same vessel. Abandon that vessel, use a different site
4. Patient complains of sudden severe pain
• You might have probably hit a venous valve / a nerve!
• Abandon the procedure.
5. Fainting
• Ask for a history of fainting, if there’s take the sample while the patient is in a lying down position
• If patient faints during the procedure abandon the procedure
• Lie down the patient          
6. Pricking an artery
• How to recognize?

Blood shoots rather than the sluggish flow seen with venous blood

Blood looks more reddish than the blackish venous blood

·         What if it happens?

Abandon the procedure and apply firm pressure over the site for at least 5 minutes

7. Pricking your self

                ·       Inform a senior nursing officer in the ward.

·         Make sure they make an entry in the needle prick register

·         HIV testing might have to be done on both yours and patient’s blood samples as necessary

·         But don’t panic, the chances of you getting it is closer to null

Early / Late

1. Severe bruising of the puncture site
2. Haematoma
3. Needle innoculation
4. Thrombophlebitis
5. Cellulitis