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Veterinary Medicine International
Volume 2013, Article ID 159489, 6 pages
Research Article

Limitations of the Use of Pressure Waves to Verify Correct Epidural Needle Position in Dogs

1Department of Veterinary Clinical Science, Anesthesiology and Pain Therapy Division, Vetsuisse Faculty, University of Berne, Länggasstraße 124, 3012 Berne, Switzerland
2Comparative Medicine Division, F. Hoffmann-La Roche AG, Grenzacherstraße 124, 4070 Basel, Switzerland

Received 21 April 2013; Revised 31 May 2013; Accepted 2 June 2013

Academic Editor: Remo Lobetti

Copyright © 2013 Chiara Adami 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.


The use of pressure waves to confirm the correct position of the epidural needle has been described in several domestic species and proposed as a valid alternative to standard methods, namely, control radiographic exam and fluoroscopy. The object of this retrospective clinical study was to evaluate the sensitivity of the epidural pressure waves as a test to verify the correct needle placement in the epidural space in dogs, in order to determine whether this technique could be useful not only in the clinical setting but also when certain knowledge of needle’s tip position is required, for instance when performing clinical research focusing on epidural anaesthesia. Of the 54 client-owned dogs undergoing elective surgeries and enrolled in this retrospective study, only 45% showed epidural pressure waves before and after epidural injection. Twenty-six percent of the animals showed epidural pressure waves only after the injection, whereas 29% of the dogs showed epidural pressure waves neither before nor after injection and were defined as false negatives. Our results show that the epidural pressure wave technique to verify epidural needle position lacks sensitivity, resulting in many false negatives. As a consequence, the applicability of this technique is limited to situations in which precise, exact knowledge of the needle's tip position is not mandatory.