犬の麻酔前投薬としてのミダゾラム-ブトルファノールの効果

山下和人^1）†　　石村尚子^1）　　都築圭子^1）　　小池政紀^1）　　井坂光宏^1）
瀬野貴弘^1）　　加藤澄江^1）　　泉澤康晴^1）
小谷忠生^1）　　William W. Muir^2）

（2000年5月10日受付・2000年12月27日受理）

要　　　　　約 　 　犬臨床例の麻酔前投薬としてミダゾラム（MID）0.3mg/kg単独またはMID 0.3mg/kghブトルファノール（BTR）0.0125〜0.1mg/kgを静脈内投与（IV）し，ケタミン5mg/kg　IVで麻酔導入後，50％笑気-50％酸素-セボフルラン麻酔下で外科手術を実施した．前投薬後，重度の全身性疾患を有するすべての犬が中等度に鎮静され伏臥した．健康な犬と軽度の全身性疾患を有する犬では，MID単独の鎮静作用は軽く，MID-BTR併用では中等度に増強された．MID単独およびMID-BTR併用のいずれにおいても，健康な犬の一部で導入後の気管内挿管が困難であり，マスク導入を実施した．術中の終末呼気セボフルラン濃度は，MID単独で2.4〜2.6％，MID-BTR　0.025mg/kgで2.3〜2.4％，MID-BTR 0.0125，0.05および0.1mg/kgで2.0〜2.2％であった．MID-BTR　0.05および0.1mg/kgでは導入後の心拍数と呼吸数が軽度に低下したが，術中の呼吸循環状態はすべての犬で良好であった．MID-BTRは軽度から重度の全身性疾患を有する犬の麻酔前投薬として有用と考えられた． ―キーワード：ブトルファノール，犬，ミダゾラム，麻酔前投薬 ． --------------------日獣会誌　54，476〜482（2001） Combination of Midazolam and Butorphanol as Premedication in Dogs Kazuto YAMASHITA＊†, Naoko ISHIMURA, Keiko TSUZUKI, Masanori KOIKE, Mitsuhiro ISAKA, Takahiro SENO, Sumie KATOH, Yasuharu IZUMISAWA, Tadao KOTANI and William W. MUIR ＊School of Veterinary Medicine, Rakuno Gakuen University, 582-1 Bunkyodai Midorimachi, Ebetsu 069-8501, Japan SUMMARY 　The effects of midazolam (0.3 mg/kg IV) alone or with the addition of butorphanol (0.0125, 0.025, 0.05, and 0.1 mg/kg IV, groups A, B, C, D, and E, n＝40 each) as combinations for premedication before inhalation anesthesia were evaluated in 200 dogs [ASA Classes I (n＝89), II (n＝86), and III (n＝25)]. Surgical anesthesia was induced by ketamine (5 mg/kg IV) and maintained with 50% nitrous oxide-50% oxygen-sevoflurane. All dogs of ASA Class III grew calm and relaxed and assumed a sternal position after premedication. Dogs of Classes I and II demonstrated mild to moderate sedation and dose-dependent sedative effects caused by butorphanol. In several dogs of ASA Class I in each group, intratracheal intubation was impossible after ketamme injection. In these cases, mask-induced oxygen-sevoflurane anesthesia was followed by intubation. Heart and respiratory rates decreased minimally after premedication; and, in groups D and E, respiratory rate decreased significantly after induction to anesthesia. End-tidal sevoflurane concentrations during surgery varied from 2.4〜2.6% in group A, 2.0〜2.1% in group B, 2.3〜2.4% in group C, 2.0〜2.2% in group D, and 2.1〜2.2% in group E. In all instances, during surgery, heart rate (130 bpm), mean arterial blood pressure (90〜110 mmHg), respiratory rate (30 bpm), and partial pressure of end-tidal CO2 (40〜50 mmHg) remained with normal canine limits. Recovery from anesthesia was rapid, and most dogs were extubated by 10 minutes after anesthesia cessation. The combination of midazolam and butorphanol is useful premedication for dogs of ASA Classes II and III. ―Key words :butorphanol, dog, midazolam, premedication. †　Correspondence to : Kazuto YAMASHITA (School of Veterinary Medicine, Rakuno Gakuen University) 582-1 Bunkyodai Midorimachi, Ebetsu 069-8501, Japan TEL・FAX 011-388-4792 --------------------　　J. Jpn. Vet. Med. Assoc., 54, 476〜482 (2001)