Intratesticular and subcutaneous lidocaine alters the intraoperative haemodynamic responses and heart rate variability in male cats undergoing castration
Version of Record online: 4 OCT 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 63–73, January 2013
How to Cite
Moldal, E. R., Eriksen, T., Kirpensteijn, J., Nødtvedt, A., Kristensen, A. T., Sparta, F. M. and Haga, H. A. (2013), Intratesticular and subcutaneous lidocaine alters the intraoperative haemodynamic responses and heart rate variability in male cats undergoing castration. Veterinary Anaesthesia and Analgesia, 40: 63–73. doi: 10.1111/j.1467-2995.2012.00773.x
- Issue online: 18 DEC 2012
- Version of Record online: 4 OCT 2012
- Received 5 September 2011; accepted 19 November 2011.
- arterial pressure;
- heart rate variability;
- local anaesthesia;
- pulse rate;
Objective To evaluate the usefulness of intratesticular and subcutaneous lidocaine in alleviating the intraoperative nociceptive response to castration, measured by pulse rate (PR) and mean arterial pressure (MAP), and to test the applicability of heart rate variability (HRV) analysis in assessing this response.
Study design Randomized, controlled, observer-blinded experimental trial.
Animals Thirty-nine healthy male cats admitted for castration.
Methods One group received general anaesthesia and served as control group (GA), while the treatment group (LA) additionally received local anaesthesia (lidocaine 2 mg kg−1) intratesticularly and subcutaneously. PR and MAP were recorded at anaesthesia baseline (T0), treatment (T1), incision left testicle (T2), traction on spermatic cord (T3), tightening of the autoligature and resection of the cord (T4), incision on the right side (T5), traction on spermatic cord (T6), and tightening of the autoligature and resection of cord (T7). HRV analysis was divided into three 5-minute intervals: baseline (H0), treatment (H1), and surgery (H2).
Results There were significant increases in PR and MAP for both groups during surgery from T3 onwards; however, the increase in the treatment group (LA) was significantly lower than for the control group (GA). For HRV analysis, significant differences were found between groups in the following parameters during surgery: TP (total power), VLF (very low frequency), SDNN (standard deviation of NN intervals [=the interval between two consecutive R-waves in the ECG]), and TI (triangular index), which were lower in the LA group. Mean NN was significantly lower in the GA group, whereas LF (low frequency) and LFn (low frequency, normalized value) were lower in the LA group. HF (high frequency) and HFn (high frequency, normalized value) decreased significantly from H1 to H2 in both groups.
Conclusions and clinical relevance The study showed that the nociceptive response to surgery was alleviated by the use of intratesticular and subcutaneous lidocaine and that HRV analysis is a promising research tool to estimate intraoperative nociception in cats during general anaesthesia.