Use the index finger and thumb to stabilize the syringe while using the other hand to pull back on the plunger slightly to look for blood. If there is blood, it means the needle is in a blood vessel and not a muscle. Although aspiration prior to intramuscular injection was standard practice until a few years ago, it is no longer recommended by the World Health Organisation and the Centres for Disease Control and Prevention. Assorted reasons given include the absence of large vessels in the delto