[Introduction and development of local anesthesia in Spain].
This study was carried out to identify key events in the history of the introduction and evolution of techniques for local anesthesia in Spain. We searched Spanish archives, finding a large number of documentary evidence, most of which is unpublished or has not been cited by other authors. Analyzing these documents with methods usually applied by medical historians, we found that techniques of local anesthesia were put into practice rapidly and widely and that they were an important factor in the development of Spanish surgery, as anesthesia made both the undertaking and the success of many procedures a real possibility.