Thank you for giving us this opportunity to respond. We wish to apologize to the editorial staff and readership of Anesthesiology and the Canadian Journal of Anesthesia .

In October 2004, we published a study in the Canadian Journal of Anesthesia ,1and in January 2005, we published another article in Anesthesiology.2At the time of the Anesthesiology submission, we failed to notify the journal of the existence of the previous article, which used the same data set and had similar methodology. Although the article in Anesthesiology expanded on the findings reported in the Canadian Journal of Anesthesia , this is inconsistent with our acknowledgment of the Instructions for Authors, which states, “Submitted manuscripts must not have been published elsewhere, in whole or in part.” We realize that journals must take this issue seriously. It is necessary to maintain integrity and provide the peer review process the complete information to thoroughly evaluate a manuscript and arrive at the optimal decision. Although not intended to hide the existence of another manuscript, our actions did not allow this process to occur. We take the issue of academic integrity seriously, and we are sincerely sorry for causing this situation.

* Duke University Medical Center, Durham, North Carolina.

Cotter JT, Nielsen KC, Guller U, Steele SM, Klein SM, Greengrass RA, Pietrobon R: Increased body mass index and ASA physical status IV are risk factors for block failure in ambulatory surgery: An analysis of 9,342 blocks. Can J Anesth 2004; 51:810–6
Nielsen KC, Guller U, Steele SM, Klein SM, Greengrass RA, Pietrobon R: Influence of obesity on surgical regional anesthesia in the ambulatory setting: An analysis of 9,038 blocks. Anesthesiology 2005; 102:181–7