Intratesticular lidocaine reduces the response to surgical castration in dogs
Article first published online: 21 SEP 2012
© 2012 The Authors. Veterinary Anaesthesia and Analgesia. © 2012 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesiologists
Veterinary Anaesthesia and Analgesia
Volume 40, Issue 1, pages 74–82, January 2013
How to Cite
Huuskonen, V., Hughes, J. L., Estaca Bañon, E. and West, E. (2013), Intratesticular lidocaine reduces the response to surgical castration in dogs. Veterinary Anaesthesia and Analgesia, 40: 74–82. doi: 10.1111/j.1467-2995.2012.00775.x
- Issue published online: 18 DEC 2012
- Article first published online: 21 SEP 2012
- Received 30 August 2011; accepted 29 November 2011.
Objective To investigate whether intratesticular injection of lidocaine pre-surgery would reduce the intraoperative responses to elective castration in dogs.
Study design Double-blinded, randomized, controlled, prospective clinical study.
Animals Forty-two client-owned dogs weighing 2.2–38.4 kg and aged between 4.5 and 56 months.
Methods Group L dogs received an intratesticular injection of 2% lidocaine (2 mg kg−1) and Group S an identical volume of saline prior to surgery. Premedication was with acepromazine and morphine intramuscularly. Anaesthesia was induced with propofol intravenously and maintained with isoflurane vaporized in oxygen. Heart rate (HR), mean arterial pressure (MAP), respiratory rate (fR), end-tidal isoflurane (Fe′ISO) and carbon dioxide concentrations, oxygen saturation and ECG were monitored during surgery. Fe′ISO was maintained at 1.0 ± 0.1%. Supplemental propofol was given in response to gross movement.
Results Group L had significantly lower maximum values for both HR and MAP. Group L displayed significantly smaller increases in HR during exteriorization of the first testis than Group S. There was an overall significant difference in MAP between groups during all surgical events (p = 0.041) and time points (p = 0.002). In univariate analysis, Group L showed significantly less changes in MAP during skin incision, exteriorization of the first testis and clamping of both spermatic cords. Group S reached its highest fR significantly earlier. Group L (eight dogs) required additional propofol 33 ± 18 minutes after the start of surgery and Group S (seven dogs) at 19 ± 17 minutes; this difference was not statistically significant. Seven dogs in Group L and 12 dogs in Group S required rescue analgesia with morphine (GCMPS-SF score ≥6); this difference was not statistically significant. No adverse effects were reported postoperatively.
Conclusions and clinical relevance Based on this study, the authors recommend the use of intratesticular lidocaine for surgical castration in dogs.