title: Effects of lidocaine constant rate infusion on sevoflurane requirement, autonomic responses, and postoperative analgesia in dogs undergoing ovariectomy under opioid-based balanced anesthesia.
abstract: The effects of constant rate infusion (CRI) of lidocaine on sevoflurane (SEVO) requirements, autonomic responses to noxious stimulation, and postoperative pain relief were evaluated in dogs undergoing opioid-based balanced anesthesia. Twenty-four dogs scheduled for elective ovariectomy were randomly assigned to one of four groups: BC, receiving buprenorphine without lidocaine; FC, receiving fentanyl without lidocaine; BL, receiving buprenorphine and lidocaine; FL, receiving fentanyl and lidocaine. Dogs were anesthetized with intravenous (IV) diazepam and ketamine and anesthesia maintained with SEVO in oxygen/air. Lidocaine (2mg/kg plus 50 μg/kg/min) or saline were infused in groups BL/FL and BC/FC, respectively. After initiation of lidocaine or saline CRI IV buprenorphine (0.02 mg/kg) or fentanyl (4 μg/kg plus 8 μg/kg/h CRI) were administered IV in BC/BL and FC/FL, respectively. Respiratory and hemodynamic variables, drug plasma concentrations, and end-tidal SEVO concentrations (E'SEVO) were measured. Behaviors and pain scores were subjectively assessed 1 and 2h post-extubation. Lidocaine CRI produced median drug plasma concentrations <0.4 μg/mL during peak surgical stimulation. Lidocaine produced a 14% decrease in E'SEVO in the BL (P<0.01) but none in the FL group and no change in cardio-pulmonary responses to surgery or postoperative behaviors and pain scores in any group. Thus, depending on the opioid used, supplementing opioid-based balanced anesthesia with lidocaine (50 μg/kg/min) may not have any or only a minor impact on anesthetic outcome in terms of total anesthetic dose, autonomic responses to visceral nociception, and postoperative analgesia.
authors.affiliation: Dipartimento di Patologia e Clinica Veterinaria, Sezione di Clinica Chirurgica Veterinaria, Facoltá di Medicina Veterinaria, Università degli Studi di Sassari, I 07100 Sassari, Italy.
authors.forename: Nicolò
authors.initials: N
authors.lastname: Columbano
authors.forename: Fabio
authors.initials: F
authors.lastname: Secci
authors.forename: Giovanni M
authors.initials: GM
authors.lastname: Careddu
authors.forename: Giovanni
authors.initials: G
authors.lastname: Sotgiu
authors.forename: Gabriele
authors.initials: G
authors.lastname: Rossi
authors.forename: Bernd
authors.initials: B
authors.lastname: Driessen
mesh_terms: D000698:Analgesia / Q000662:veterinary; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D000779:Anesthetics, Local / Q000008:administration & dosage*; D000818:Animals; D058126:Balanced Anesthesia / Q000379:methods* / Q000662:veterinary; D002047:Buprenorphine / Q000008:administration & dosage; D004285:Dogs; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage; D007262:Infusions, Intravenous / Q000662:veterinary; D008012:Lidocaine / Q000008:administration & dosage*; D008738:Methyl Ethers / Q000008:administration & dosage*; D010052:Ovariectomy / Q000662:veterinary; D010149:Postoperative Pain / Q000188:drug therapy / Q000662:veterinary; D011446:Prospective Studies; D000077149:Sevoflurane; D016037:Single-Blind Method
chemical_list: D000701:Analgesics, Opioid; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D000779:Anesthetics, Local; D008738:Methyl Ethers; D000077149:Sevoflurane; D002047:Buprenorphine; D008012:Lidocaine; D005283:Fentanyl