title: Effect of Lidocaine-Ketamine Infusions Combined with Morphine or Fentanyl in Sevoflurane-Anesthetized Pigs.
abstract: Providing lidocaine, ketamine, and an opioid greatly decreases the minimum alveolar concentration (MAC) of volatile anesthetics in dogs. However, the efficacy of this combination shows marked interspecies variation, and opioids are likely to be less effective in pigs than in other species. The aim of the study was to determine the effects of constant-rate infusion of lidocaine and ketamine combined with either morphine or fentanyl on the MAC of sevoflurane in pigs. In a prospective, randomized, crossover design, 8 healthy crossbred pigs were premedicated with ketamine and midazolam, and anesthesia was induced and maintained with sevoflurane. Pigs then received ketamine (0.6 mg/kg/h) and lidocaine (3 mg/kg/h) combined with either morphine (0.24 mg/kg/h; MLK) or fentanyl (0.0045 mg/kg/h; FLK) after a loading dose; the control group received Ringers lactate solution. The anesthetic-sparing action of the 2 infusion protocols was calculated according to the MAC, by using dewclaw clamping as the standard noxious stimulus. The sevoflurane MAC (mean ± 1 SD) was 2.0% ± 0.2%, 1.9% ± 0.4%, and 1.8% ± 0.2% in the control, MLK, and FLK groups, respectively. No differences among groups or treatments were found. In conclusion, the administration of MLK or FLK at the studied doses did not reduce the MAC of sevoflurane in pigs.
authors.affiliation: Department of Animal Medicine and Surgery, Veterinary Faculty, Complutense University of Madrid, Madrid, Spain.
authors.forename: Michela
authors.initials: M
authors.lastname: Re
authors.affiliation: Department of Animal Medicine and Surgery, Veterinary Faculty, Complutense University of Madrid, Madrid, Spain.
authors.forename: Susana
authors.initials: S
authors.lastname: Canfrán
authors.affiliation: Department of Experimental Surgery, La Paz University Hospital, Madrid, Spain.
authors.forename: Carlota
authors.initials: C
authors.lastname: Largo
authors.affiliation: Department of Animal Medicine and Surgery, Veterinary Faculty, Complutense University of Madrid, Madrid, Spain. iagsegura@vet.ucm.es.
authors.forename: Ignacioa A
authors.initials: IA
authors.lastname: Gómez de Segura
mesh_terms: D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D000818:Animals; D004285:Dogs; D004359:Drug Therapy, Combination; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage*; D007649:Ketamine / Q000008:administration & dosage*; D008012:Lidocaine / Q000008:administration & dosage*; D008738:Methyl Ethers / Q000008:administration & dosage*; D009020:Morphine / Q000008:administration & dosage*; D011446:Prospective Studies; D011650:Pulmonary Alveoli; D000077149:Sevoflurane; D034421:Sus scrofa; D013552:Swine
chemical_list: D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane; D007649:Ketamine; D009020:Morphine; D008012:Lidocaine; D005283:Fentanyl