The click is best felt when a short bevelled needle is used. Aspirate to exclude intravascular placement of the needle and then inject the local anaesthetic solution. During the injection aspirate again to ensure that the needle has not changed position and entered a vessel. The injection is most conveniently performed with an extension set between the syringe and the needle. This allows the syringe to be changed without moving the needle.
Some anaesthetists place a cannula into the sheath to allow further top ups of local anaesthesia.
If firm pressure is placed over the sheath below the point of injection the local anaesthetic solution is encouraged towards the axilla and a better block will result. If it is planned to use a tourniquet during surgery some subcutaneous infiltration of local anaesthetic on the medial side of the upper arm will often improve the comfort of the patient. Volumes of local anaesthetic This will depend on the size of the patient and the drugs available. Contraindications Damage or disease of the brachial plexus. Sepsis in the axilla.