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Anesthesiology Research and Practice
Volume 2015 (2015), Article ID 545902, 6 pages
Research Article

Measurements of Epidural Space Depth Using Preexisting CT Scans Correlate with Loss of Resistance Depth during Thoracic Epidural Catheter Placement

1Department of Anesthesiology and Pain Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
2Department of Radiology, University of Washington School of Medicine, Seattle, WA 98195, USA

Received 8 August 2014; Accepted 21 December 2014

Academic Editor: Enrico Camporesi

Copyright © 2015 Nathaniel H. Greene et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Background. Thoracic epidural catheters provide the best quality postoperative pain relief for major abdominal and thoracic surgical procedures, but placement is one of the most challenging procedures in the repertoire of an anesthesiologist. Most patients presenting for a procedure that would benefit from a thoracic epidural catheter have already had high resolution imaging that may be useful to assist placement of a catheter. Methods. This retrospective study used data from 168 patients to examine the association and predictive power of epidural-skin distance (ESD) on computed tomography (CT) to determine loss of resistance depth acquired during epidural placement. Additionally, the ability of anesthesiologists to measure this distance was compared to a radiologist, who specializes in spine imaging. Results. There was a strong association between CT measurement and loss of resistance depth (); the presence of morbid obesity () changed this relationship (). The ability of anesthesiologists to make CT measurements was similar to a gold standard radiologist (all individual ). Conclusions. Overall, this study supports the examination of a recent CT scan to aid in the placement of a thoracic epidural catheter. Making use of these scans may lead to faster epidural placements, fewer accidental dural punctures, and better epidural blockade.