Determination of acute tolerance and hyperalgesia to remifentanil constant rate infusion in dogs undergoing sevoflurane anaesthesia. (March 2020)

• Record Type: Journal Article
• Authors: Ruíz-López, Patricia; Navarrete-Calvo, Rocío; Morgaz, Juan; Domínguez, Juan Manuel; Quirós-Carmona, Setefilla; Muñoz-Rascón, Pilar; Gómez-Villamandos, Rafael Jesús; Fernández-Sarmiento, José Andrés; Granados, M.M.
• Is Part Of: Veterinary anaesthesia and analgesia. Volume 47:Number 2(2020)
• Page Start: 183
• Page End: 190
• Publication Date: 2020-03
• Subjects: dog -- hyperalgesia -- opioid -- remifentanil -- tolerance; Veterinary anesthesia -- Periodicals; 636.089
• DOI: 10.1016/j.vaa.2019.09.005
• Languages: English
• ISSNs: 1467-2987

Abstract

Abstract: Objective: To determine if acute opioid tolerance (AOT) or opioid-induced hyperalgesia (OIH) could develop and limit the remifentanil-induced reduction in the sevoflurane minimum alveolar concentration (MAC). The response to mechanical nociceptive threshold (MNT) was evaluated and related to OIH. Study design: A crossover, randomized, experimental animal study. Animals: A total of nine Beagle dogs. Methods: The dogs were anaesthetized with sevoflurane in 50% oxygen. Baseline sevoflurane MAC was measured (MACb1). Remifentanil (0.3 μg kg –1 minute –1 ) or 0.9% saline constant rate infusion (CRI) was administered intravenously (IV). Sevoflurane MAC was determined 20 minutes after CRI was initiated (MACpostdrug1), 30 minutes after MACpostdrug1 determination (MACpostdrug2) and after 1 week (MACb2). The MNT was determined at baseline (before anaesthesia), 3 and 7 days after anaesthesia. An increase of MACpostdrug2 ≥0.25% compared to MACpostdrug1 was considered evidence of AOT. A decrease in MNT at 3 and 7 days or an increase in MACb2 or both with respect to MACb1 were considered evidence of OIH. Results: Remifentanil CRI reduced sevoflurane MACpostdrug1 by 43.7% with respect to MACb1. MACpostdrug2 was no different from MACpostdrug1 with the saline ( p = 0.62) or remifentanil ( p = 0.78) treatments. No significant differences were observed in the saline ( p = 0.99) or remifentanil ( p = 0.99) treatments between MACb1 and MACb2, or for MNT values between baseline, 3 and 7 days. Conclusion and clinical relevance: In dogs, under the study conditions, remifentanil efficacy in reducing sevoflurane MAC did not diminish in the short term, suggesting remifentanil did not induce AOT. Hyperalgesia was not detected 3 or 7 days after the administration of remifentanil. Contrary to data from humans and rodents, development of AOT or OIH in dogs is not supported by the findings of this study.