This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief as it contains fabricated/falsified data. The Editor-in-Chief decision was based on the investigation by the Japanese Society of Anesthesiologists which concluded that no research was conducted and all the data including patient backgrounds were fabricated. The society also concluded that the corresponding author, Dr. Ueshima presented the names of the individuals not involved or only partially involved in research as lead authors, presented the names of the individuals not involved in research as co-authors and submitted papers without the agreement of the co-authors. The investigation report can be found here.