Nerve block anaesthesia is wildly practised in France, avoiding general anaesthesia in a number of cases and producing excellent post-operative analgesia in trauma and orthopaedic surgeries. Even realised by experimented anaesthetists, 5-15% of failures and rare complications (such as vascular puncture, paresthesia, systemic local anaesthetic toxicity, epidural and spinal anaesthesia, neuropathy) are noticed. The aim of the study is the evaluation of an ultrasound-guidance technique in the four predetermined blocks and the incidence of their complications.

Inclusion Criteria:

• Patients aged 18 years and greater, scheduled for one of these blocks: interscalene, humeral, parasacral or lumbar blocks, for trauma or orthopaedic surgeries, who have consented to the study and are with social insurance registration

Exclusion Criteria:

• Block's contraindications, treatment by verapamil or flecainide