title: Cardiorespiratory effects of isoflurane in Asiatic black bears (Ursus thibetanus) anesthetized with intramuscular medetomidine and zolazepam/tiletamine.
abstract: The objective of this study was to determine the dose-dependent effects of isoflurane on various cardiovascular parameters and the stable range of isoflurane concentrations in Asiatic black bears (Ursus thibetanus). Seven Asiatic black bears were intramuscularly injected with medetomidine, zolazepam and tiletamine (MZT) to induce anesthesia, and anesthesia was maintained by administering isoflurane in 100% oxygen (4 l/min) without mechanical ventilation. Several cardiovascular parameters were measured at five end-tidal isoflurane concentrations (0.5, 1.0, 1.5, 2.0, and 2.5%). Blood was collected from the femoral artery before administration of isoflurane and after each administration for immediate blood gas analysis. Isoflurane produced dose-dependent increases in heart rate, respiratory rate, minute volume, end-tidal carbon dioxide (CO2) partial pressure and the partial pressure of arterial CO2, and dose-dependent decreases in non-invasive blood pressure and tidal volume. Rectal temperature, oxygenation and acid-base balance were unaffected by isoflurane. All parameters in this study were in a clinically acceptable range at all times. The data show that the combination of MZT and isoflurane is suitable for general anesthesia in Asiatic black bears with spontaneous breathing during prolonged procedures. End-tidal isoflurane concentrations of 0.5 to 2.5% can be used in Asiatic black bears without adverse side effects.
authors.affiliation: Species Restoration Technology Institute of Korea National Park Service, Gurye 542-853, Republic of Korea.
authors.forename: Dong-Hyuk
authors.initials: DH
authors.lastname: Jeong
authors.forename: Jeong-Jin
authors.initials: JJ
authors.lastname: Yang
authors.forename: Seong-Hoon
authors.initials: SH
authors.lastname: Seok
authors.forename: Dong-Joo
authors.initials: DJ
authors.lastname: Song
authors.forename: Seong-Chan
authors.initials: SC
authors.lastname: Yeon
mesh_terms: D000768:Anesthesia, General / Q000662:veterinary*; D019162:Anesthetics, Combined; D000818:Animals; D001831:Body Temperature; D004338:Drug Combinations; D006339:Heart Rate; D007530:Isoflurane; D008297:Male; D020926:Medetomidine; D012119:Respiration; D013992:Tiletamine; D001503:Ursidae; D015041:Zolazepam
chemical_list: D019162:Anesthetics, Combined; D004338:Drug Combinations; C006131:tiletamine, zolazepam drug combination; D013992:Tiletamine; D007530:Isoflurane; D015041:Zolazepam; D020926:Medetomidine