Avoiding nerve damage when performing a venepuncture requires using correct procedure during the blood draw. Venepunctures, performed correctly, carry a low risk of any type of injury. An understanding of human anatomy (the location of nerves adjacent to veins) and the ability to successfully enter a vein using the fewest number of attempts will minimise this risk even further. This type of expertise comes from years of study and practice, but there are best practices to keep in mind at any point in your phlebotomy career to prevent damaging nerves.
Choose the venepuncture location carefully. There are areas of the body that carry higher risk of hitting or damaging nerves than others (for example, the inside of the wrist).
Use proper venepuncture technique. Palpitate and locate the vein thoroughly before entering with a needle. Note the direction and depth of the vein and use an angle of needle entry appropriate for that vein.
Pull the skin taut and anchor the vein with a gloved finger before you enter the vein. This will minimise your risk of "missing" the vein and hitting a nerve (or causing a hematoma).
Listen to and watch the patient. If you hit a nerve, the patient may jerk his arm or describe a shocking pain. If your patient reports this, immediately stop the procedure and remove the needle. Instruct the patient to elevate his arm and use ice and light pressure on the site.
If you fear that you may have hit or damaged a nerve, document the procedure completely using your company or laboratory's reporting system. Do this as soon as you can in order to document as many details as possible.