Venepuncture Flashcards
How would you explain to a patient what venepuncture is?
Procedure to obtain a blood sample from the vein
Used to either confirm a diagnosis of a suspected condition or to monitor levels of a blood component
What are the 2 main reasons why a venepuncture is performed?
Aid diagnosis of a condition
Monitor blood component levels
Before performing venepuncture, what 2 patient details should you confirm?
Patient name, DOB, first line of address: Should match referral letter
Consent
Before performing venepuncture, what 4 questions should you ask the patient in terms of their medical history?
Are they taking any anticoagulants eg. aspirin, warfarin
Do they have any clotting or bleeding disorders
Do they have a latex allergy
Have they had any reactions to blood draws in the past
Before performing venepuncture, how should you position the patient?
Sitting up in a chair with back supported/supine if anxious or at risk of collapse
Put pillow under straight arm, make sure that arm is lower than heart level
Before performing venepuncture, what PPE should you wear?
Gloves
Plastic apron
How do you decide which arm to take a venepuncture sample from?
Ask patient if they have a preferred arm for blood draws
Where on the arm is the insertion site for venepuncture?
Antecubital fossa (upside down triangle) of elbow
What are the 3 main veins in the antecubital fossa which are used for venepuncture?
Median cephalic vein: Medial aspect
Median basilic vein: Lateral aspect
Median cubital vein: Medial aspect of arm, going diagonally upwards
Out of the 3 veins in the antecubital fossa, which is most preferred for venepuncture and why?
- Median cubital vein: Most superficial, large lumen and doesn’t roll
When performing venepuncture, how should you decide if the vein is suitable?
Apply torniquet to patient’s arm
Put on sterile gloves
Palpate veins with fingertips
At what point in the venepuncture procedure should you apply the torniquet, and what does this do?
Tightly apply torniquet after confirming patient details and donning sterile gloves
Increases venous filling so makes them more prominent to palpate and enter
In venepuncture, where should you apply the torniquet and for how long?
4-5 fingertip widths or 7-8 cm above insertion site
60-90 seconds
When palpating suitable veins for venepuncture, what are the 4 qualities of a good vein?
Soft
Bouncy
Straight
Refills when depressed
When palpating suitable veins for venepuncture, what are 4 features of a bad vein?
Sclerosed or fibrosed veins (feel hard to touch)
Surrounding skin looks infected, erythematous, bruised
Limb has edema
Narrow
After palpating a suitable vein, how should you clean the insertion site for venepuncture?
Clean with alcohol wipe, leave to dry before blood draw
Cannot palpate vein again after cleaning area
Before inserting the needle for venepuncture, how do you stabilise the vein without rolling it?
Pull skin below insertion site taut with thumb in opposite direction to needle insertion
Hold taut until procedure is completed and needle has been removed
Which 3 needles can be used for venepuncture?
Butterfly needle
Vacutainer needle
Straight needle
What are the 3 indications for using butterfly needles in venepuncture?
Thin, fragile veins
Young or elderly patients
Using veins in hand dorsum
What are the indications for using a vacutainer needle in venepuncture?
Contain additives to lower risk of haemolysis
Allow multiple tube draws
Reduces risk of needle-stick injury
How do you correctly hold and insert a butterfly needle for venepuncture?
Bevel facing upwards so that point enters skin first, hold with thumb on top and pointer, middle fingers below needle
Insert at 10-30 degrees into vein whilst stabilising vein
How do you know when the butterfly needle has entered the vein, and what do you do after this?
Flashback of blood in the collection device
Can now connect tubes for blood draw to the collection device
If there is no flashback in the needle, how do you fix this?
Withdraw needle slightly whilst still stabilising vein and move around
How do you hold and insert a vacutainer needle for venepuncture?
Hold with bevel facing upwards and safety cap above needle, then place thumb below safety cap and hold from below with pointer and middle fingers
Stabilise vein and insert needle at 10-30 degrees
After filling a tube with a blood sample in venepuncture, what should you do to prevent haemolysis of the sample?
Gently invert tube 4-6 times
Fill up tubes to correct amount by filling to the line on the tube
When should you remove the torniquet?
When the last tube is almost filled to the correct amount
How do you remove the needle from the vein after venepuncture?
Press gauze over insertion site then remove needle
Apply pressure with gauze for a minute or until bleeding stops
How should you safely dispose of the needle after venepuncture?
Put on safety cap with needle facing away from you, discard in sharps bin
Don’t need to disconnect needle from blood collection device
After you have disposed of the needle, what should you do with the patient?
Check if the venepuncture site is still bleeding, if so tape gauze on
How do you label the blood samples after venepuncture?
Complete details on specimen request form: Date, time, who took sample
Remove labels from request form and stick on tubes, write details in all caps
