1. Effects of tasipimidine premedication with and without methadone and dexmedetomidine on cardiovascular variables during propofol-isoflurane anaesthesia in Beagle dogs.
- Author
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Kästner SB, Amon T, Tünsmeyer J, Noll M, Söbbeler FJ, Laakso S, Saloranta L, and Huhtinen M
- Subjects
- Animals, Dogs, Female, Heart Rate drug effects, Male, Blood Pressure drug effects, Hypnotics and Sedatives pharmacology, Hypnotics and Sedatives administration & dosage, Quinolizines pharmacology, Quinolizines administration & dosage, Anesthetics, Intravenous administration & dosage, Anesthetics, Intravenous pharmacology, Anesthetics, Inhalation administration & dosage, Anesthetics, Inhalation pharmacology, Premedication veterinary, Dexmedetomidine administration & dosage, Dexmedetomidine pharmacology, Propofol administration & dosage, Propofol pharmacology, Methadone administration & dosage, Methadone pharmacology, Isoflurane administration & dosage, Isoflurane pharmacology, Pyrazoles
- Abstract
Objective: To evaluate cardiovascular effects of oral tasipimidine on propofol-isoflurane anaesthesia with or without methadone and dexmedetomidine at equianaesthetic levels., Study Design: Prospective, placebo-controlled, blinded, experimental trial., Animals: A group of seven adult Beagle dogs weighing (mean ± standard deviation) 12.4 ± 2.6 kg and a mean age of 20.6 ± 1 months., Methods: The dogs underwent four treatments 60 minutes before induction of anaesthesia with propofol. PP: placebo orally and placebo (NaCl 0.9%) intravenously (IV); TP: tasipimidine 30 μg kg
-1 orally and placebo IV; TMP: tasipimidine 30 μg kg-1 orally and methadone 0.2 mg kg-1 IV; and TMPD: tasipimidine 30 μg kg-1 orally with methadone 0.2 mg kg-1 and dexmedetomidine 1 μg kg-1 IV followed by 1 μg kg-1 hour-1 . Isoflurane in oxygen was maintained for 120 minutes at 1.2 individual minimum alveolar concentration preventing motor movement. Cardiac output (CO), tissue blood flow (tbf), tissue oxygen saturation (stO2 ) and relative haemoglobin content were determined. Arterial and mixed venous blood gases, arterial and pulmonary artery pressures and heart rate (HR) were measured at baseline; 60 minutes after oral premedication; 5 minutes after IV premedication; 15, 30, 60, 90 and 120 minutes after propofol injection; and 30 minutes after switching the vaporiser off. Data were analysed by two-way anova for repeated measures; p < 0.05., Results: Tasipimidine induced a significant 20-30% reduction in HR and CO with decreases in MAP (10-15%), tbf (40%) and stO2 (43%). Blood pressure and oxygenation variables were mainly influenced by propofol-isoflurane-oxygen anaesthesia, preceded by short-lived alterations related to IV methadone and dexmedetomidine., Conclusions and Clinical Relevance: Tasipimidine induced mild to moderate cardiovascular depression. It can be incorporated into a common anaesthetic protocol without detrimental effects in healthy dogs, when anaesthetics are administered to effect and cardiorespiratory function is monitored., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)- Published
- 2024
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