The effects of propofol, isoflurane and sevoflurane on vecuronium infusion rates for surgical muscle relaxation in dogs
Article first published online: 19 DEC 2005
Veterinary Anaesthesia and Analgesia
Volume 33, Issue 3, pages 169–174, May 2006
How to Cite
Nagahama, S., Nishimura, R., Mochizuki, M. and Sasaki, N. (2006), The effects of propofol, isoflurane and sevoflurane on vecuronium infusion rates for surgical muscle relaxation in dogs. Veterinary Anaesthesia and Analgesia, 33: 169–174. doi: 10.1111/j.1467-2995.2005.00252.x
- Issue published online: 19 DEC 2005
- Article first published online: 19 DEC 2005
- Received 24 January 2005; Accepted 27 April 2005
- constant rate infusion;
- inhalation anaesthesia;
- total intravenous anaesthesia;
Objective To compare the constant rate infusion (CRI) of vecuronium required to maintain a level of neuromuscular blockade adequate for major surgeries, e.g. thoracotomy or laparotomy, in dogs anaesthetized with a CRI of fentanyl and either propofol, isoflurane or sevoflurane.
Study design Prospective, randomized, cross-over study.
Animals Thirteen male beagles (age, 9–22 months; body mass 6.3–11.3 kg).
Materials and methods Dogs were anaesthetized with propofol (24 mg kg−1 hour−1 IV CRI; group P), isoflurane (1.3% end-tidal concentration; group I) or sevoflurane (2.3% end-tidal concentration; group S) with fentanyl (5 μg kg−1 hour−1 IV, CRI). Sixty to seventy minutes after induction of anaesthesia, vecuronium was administered at a rate of 0.4, 0.3 and 0.2 mg kg−1 hour−1 in groups P, I and S respectively. To determine the degree of neuromuscular block, a peripheral nerve was stimulated electrically using the train-of-four (TO4) stimulus pattern. Evoked muscle contractions were evaluated using a neuromuscular monitoring device. Once the TO4 ratio reached 0, the continuous infusion rate was decreased and adjusted to maintain a TO4 count of 1. Continuous infusion was continued for 2 hours. The infusion rate of vecuronium was recorded 20, 40, 60, 80, 100 and 120 minutes after the start of infusion.
Results The mean continuous infusion rates of vecuronium during stable infusion were 0.22 ± 0.04 (mean ± SD), 0.10 ± 0.02 and 0.09 ± 0.02 mg kg−1 hour−1 in groups P, I and S respectively. There were statistically significant differences between the rates in groups P and I and between the rates in groups P and S.
Conclusions and clinical relevance In healthy dogs, the recommended maintenance infusion rate of vecuronium is 0.2 mg kg−1 hour−1 under CRI propofol–fentanyl anaesthesia and 0.1 mg kg−1 hour−1 during CRI fentanyl–isoflurane or sevoflurane anaesthesia