Other local anaesthetic agents like lignocaine or prilocaine may be used. Complications Inadvertent epidural or subarachnoid injection is a potentially serious complication resulting from incorrect needle placement. Vertebral artery injection, this can result in convulsions and loss of consciousness. Phrenic nerve block is frequently produced, this complication precludes bilateral use of this technique. Recurrent laryngeal, vagus, and cervical sympathetic nerves are sometimes blocked.
Pneumothorax is rare but can happen with deep placement of the needle and in unskilled hands.