Venepuncture refers to drawing blood from a vein by means of a puncture. Performed by a trained professional known as a phlebotomist, this procedure requires skills in identifying a vein, inserting a needle into that vein and then extracting blood without any complications. Despite the care taken and prior training, complications may arise from venepuncture collection.
Better known as bruising, this complication arises more often than any other problem associated with venepuncture collection. Blood leaking from the vein causes this problem, which is more prevalent in women, the elderly and persons with small or difficult-to-access veins. In most cases, the bruising is minor and resolves itself without any treatment other than compression and ice. It can, however, leave an ugly mark on the arm for a few days.
On rare occasions, the needle punctures an artery instead of a vein. This causes a deep pain and a large resulting bruise, although there is generally no long-term effect.
Diaphoresis and Syncope
These two complications both arise from nervousness on behalf of the patient. Many people become very fearful at the thought of blood being drawn from their arm. They develop extensive sweating, known as diaphoresis. In extreme cases, they may lose consciousness, known as syncope. While these conditions appear to be non-severe, fainting can be dangerous if the head strikes an object when the patient falls.
On rare occasions, the needle can hit a small sensory nerve that runs close to the vein when it enters the arm. If this happens, the patient experiences an electric shock-like pain. While that may be the extent of the damage, it can linger for up to several weeks with a tingling feeling, but eventually it heals.