Currently there is no globally accepted standard by which to assess when surgical anaesthesia has been achieved following administration of PNBs. The decision as to when adequate surgical anaesthesia has been achieved and when surgery can then proceed is usually left to the discretion of the anaesthetist. The anaesthetist can assess nerve blockade though several motor and sensory function tests: cold, heat, touch and pinprick sensitivity. Several scoring systems have been described using these tests to estimate when surgical anaesthesia has been achieved but none have been independently validated outside of the original studies in which they have been described.