title: Discussion.
mesh_terms: D015360:Analgesia, Epidural / Q000379:methods*; D002404:Catheterization / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D009407:Nerve Block / Q000379:methods*; D010149:Postoperative Pain / Q000517:prevention & control*; D013908:Thoracotomy / Q000009:adverse effects*