Heidi S Lehmann1, Gabrielle C Musk2, Michael Laurence2, Timothy H Hyndman2, Jonathan Tuke3, Teresa Collins2, Karina B Gleerup4, Craig B Johnson5. 1. College of Veterinary Medicine, School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia. Electronic address: h.s.lehmann@icloud.com. 2. College of Veterinary Medicine, School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia. 3. School of Mathematics, University of Adelaide, Adelaide, Australia. 4. Department of Large Animal Sciences, University of Copenhagen, Denmark. 5. Institute of Veterinary, Animal and Biomedical Sciences, Massey University, New Zealand.
Abstract
OBJECTIVE: To investigate the mitigating effects of administration of local anaesthetic or systemic meloxicam on the electroencephalographic (EEG) and cardiovascular responses during surgical castration of Bos indicus bull calves. STUDY DESIGN: Prospective, randomized, experimental study. ANIMALS: Thirty-six 6-8 month-old Bos indicus bull calves, with a mean ± standard deviation weight of 237 ± 19 kg. METHODS: Animals were allocated randomly to three groups of 12 (group L, 260 mg of 2% lidocaine subcutaneously and intratesticularly 5 minutes prior to castration; group M, 0.5 mg kg-1 of meloxicam subcutaneously 30 minutes prior to castration; group C, no preoperative analgesia administered). Anaesthesia was induced and maintained with halothane (0.9-1.1%) in oxygen. Electroencephalogram, heart rate (HR) and mean blood pressure (MAP) were recorded for 300 seconds prior to (baseline, B) and from the start of surgery (first testicle removal, T1). HR and MAP were compared at 10 second intervals for 90 seconds from the start of T1. Median frequency (F50), spectral edge frequency (F95) and total power of the EEG (Ptot) were analysed using area under the curve comparing T1 to B. RESULTS: All EEG variables were significantly different between B and T1 (p ≤ 0.0001). No differences in F50 were found between groups during T1 (p = 0.6491). F95 and Ptot were significantly different between group L and groups C and M during T1 (p = 0.0005 and 0.0163, respectively). There were transient significant changes in HR and MAP in groups L and M compared to group C during the 20-50 second periods. CONCLUSIONS: The EEG changes indicate nociceptive responses in all three groups during surgical castration, greater in group L compared to groups C and M. Both analgesics attenuated the peracute cardiovascular response. Lidocaine and meloxicam administered prior to castration attenuated these responses in Bos indicus bull calves. CLINICAL RELEVANCE: These findings provide support for the preoperative administration of lidocaine and potentially meloxicam for castration in Bos indicus bull calves.
OBJECTIVE: To investigate the mitigating effects of administration of local anaesthetic or systemic meloxicam on the electroencephalographic (EEG) and cardiovascular responses during surgical castration of Bos indicus bull calves. STUDY DESIGN: Prospective, randomized, experimental study. ANIMALS: Thirty-six 6-8 month-old Bos indicus bull calves, with a mean ± standard deviation weight of 237 ± 19 kg. METHODS: Animals were allocated randomly to three groups of 12 (group L, 260 mg of 2% lidocaine subcutaneously and intratesticularly 5 minutes prior to castration; group M, 0.5 mg kg-1 of meloxicam subcutaneously 30 minutes prior to castration; group C, no preoperative analgesia administered). Anaesthesia was induced and maintained with halothane (0.9-1.1%) in oxygen. Electroencephalogram, heart rate (HR) and mean blood pressure (MAP) were recorded for 300 seconds prior to (baseline, B) and from the start of surgery (first testicle removal, T1). HR and MAP were compared at 10 second intervals for 90 seconds from the start of T1. Median frequency (F50), spectral edge frequency (F95) and total power of the EEG (Ptot) were analysed using area under the curve comparing T1 to B. RESULTS: All EEG variables were significantly different between B and T1 (p ≤ 0.0001). No differences in F50 were found between groups during T1 (p = 0.6491). F95 and Ptot were significantly different between group L and groups C and M during T1 (p = 0.0005 and 0.0163, respectively). There were transient significant changes in HR and MAP in groups L and M compared to group C during the 20-50 second periods. CONCLUSIONS: The EEG changes indicate nociceptive responses in all three groups during surgical castration, greater in group L compared to groups C and M. Both analgesics attenuated the peracute cardiovascular response. Lidocaine and meloxicam administered prior to castration attenuated these responses in Bos indicus bull calves. CLINICAL RELEVANCE: These findings provide support for the preoperative administration of lidocaine and potentially meloxicam for castration in Bos indicus bull calves.
Authors: Brooklyn K Wagner; Emma Nixon; Ivelisse Robles; Ronald E Baynes; Johann F Coetzee; Monique D Pairis-Garcia Journal: Animals (Basel) Date: 2021-01-22 Impact factor: 2.752
Authors: Daniela M Meléndez; Sonia Marti; Edmond A Pajor; Pritam K Sidhu; Désirée Gellatly; Diego Moya; Eugene D Janzen; Johann F Coetzee; Karen S Schwartzkopf-Genswein Journal: PLoS One Date: 2018-11-30 Impact factor: 3.240