In such case, it is easy to understand that following points are important: - the needle has to be as much flexible as possible. ( That s why we chose BD) - never remove the bubbles through the needle, which will be in contact with the patient, otherwise the needle will be hard at 1 st injection, which may create pain and discomfort to the patient. - never take off the syringe-needle slowly, otherwise you may traumatise the tissues with a ,, hard,, needle, which will provoke an unuseful pain and edema. - if you have difficulties to inject, remove immediately the needle from syringe and put a new needle. - if the patient feels pain at moment of injection, remove the needle from syringe and put a new needle - control at each injection if your needle is not curved.In case your needle is not any more straight, remove it and put a new needle.