目 的
快速恢复注射麻醉有利于猫收容所绝育项目。在成年猫和小猫(⩽6个月大)中评估美托咪定、右美托咪定和阿替美唑对恢复的影响。
方 法
选取年龄2 ~ 66月龄、体重0.7 ~ 5.3 kg的健康雄性猫100只，随机分为25只。氯胺酮60 mg/m2、丁丙诺啡180µg/m2、咪达唑仑3 mg/m2，美托咪定600µg/m2 (M组和MA组)或右美托咪定300µg/m2 (D组和DA组)肌注麻醉(IM)。MA组、DA组40 min后给予阿替美唑1.5 mg/m2 IM。记录准备时间、手术时间、趴卧位和站立时间。数据采用Kruskall-Wallis检验、未配对t检验和方差分析进行分析。P⩽0.05为差异有统计学意义。
结 果
各组在年龄、体重、术前准备及手术时间等方面差异无统计学意义。MA组(64±34 min)小于M组(129±32 min)， DA组(54±6 min)小于D组(110±27 min) (P <0.001)。M组和D组、MA组和DA组的趴卧位恢复时间无差异。MA组(79±51 min)小于M组(150±38 min) (P <0.001)， DA组(70±22 min)小于D组(126±27 min) (P <0.01)。D组站立时间(126±27 min)小于M组(150±38 min) (P <0.05)。DA组和MA组站立时间无显著差异。使用阿替美唑后，小猫恢复得比成年猫快。副作用很小。
结 论
阿替美唑可有效缩短右美托咪定或美托咪定麻醉后的恢复时间；然而，选择右美托咪定或美托咪定对小猫的恢复速度影响甚微。
个人经验与感想
1.幼龄犬猫麻醉是所有新晋麻醉医生的噩梦，这篇文章，会给大家不一样的视角。同时，不要忘记，麻醉不仅仅是麻醉前用药，术中监护才是重中之重！
2.本人临床中遇到最常见的幼猫麻醉，多数与先天性疾病相关，例如：锁肛【继发巨结肠】、门脉短路、腹膜心包膈疝等，偶见眼球异常需要摘除、消化道异物及外伤需要处置等。
幼龄猫常见耳道感染引起的外周前庭问题，需要进行CT/MRI的扫查及耳道内窥镜的清洗及检查。
3.幼龄动物高度依赖心率来维持心输出量及血压。然而它们的交感神经系统发育不完全，会导致它们无法耐受和调整由于失血或麻醉药物导致的低血压等。
4.幼龄动物的气管管径较小，肺容积小，顺应差，潮气量过低；肝肾系统未完全发育，影响术前用药的代谢速度；肝脏储存糖原较少，糖异生能力较差；体毛较少，皮下脂肪含量较少，体表面积较大；体型较小，难以精确监测ECG及血压。上述生理学的知识都需要临床麻醉医生学习并掌握。
5.回归本文，本文采取的术前用药种类较多，本人不建议单一使用右美托咪定作为幼龄动物的术前用药，且日常右美托咪定使用剂量不超过10ug/kg。若遇到过度肥胖的动物，需按照BCS分级或体表面积调整用药剂量。除此之外，幼龄动物手术时，麻醉医生需明确手术预估时间及术中失血的情况，以确定麻醉方案及是否需要术前输血或备血。
6.愿新生儿及幼龄犬猫都健健康康！
Injectable anaesthesia for adult cat and kitten castration: effects of medetomidine, dexmedetomidine and atipamezole on recoveryObjectives Rapid recovery from injectable anaesthesia benefits cat shelter neutering programmes. The effects of medetomidine, dexmedetomidine and atipamezole on recovery were evaluated in adult cats and kittens (⩽6 months old).Methods One hundred healthy male cats (age range 2–66 months, weight range 0.7–5.3 kg) admitted forneutering were randomly allocated to groups of 25. Anaesthesia was induced with 60 mg/m2 ketamine, 180 µg/m2buprenorphine, 3 mg/m2 midazolam and either 600 µg/m2 medetomidine (groups M and MA) or 300 µg/m2dexmedetomidine (groups D and DA) intramuscularly (IM). Groups MA and DA also received 1.5 mg/m2 atipamezole IM after 40 mins. Preparation time, surgical time, and times to sternal recumbency and standing were recorded. Data were analysed using the Kruskall–Wallis test, unpaired t-tests and ANOVA. Statistical significance was deemed to be P ⩽0.05.Results Groups did not differ significantly in age, body weight, preparation or surgical time. The time to sternal recumbency in group MA (64 ± 34 mins) was less than in group M (129 ± 32 mins), and in group DA it was less than in group D (54 ± 6 mins vs 110 ± 27 mins) (P <0.001). There were no differences in duration of recovery to sternal recumbency between groups M and D or MA and DA. The time to standing in group MA (79 ± 51 mins) was less than in group M (150 ± 38 mins) (P <0.001), and in group DA it was less than in group D (70 ± 22 mins vs 126 ± 27 mins) (P <0.01). Time to standing in group D (126 ± 27 mins) was less than in group M (150 ± 38 mins) (P <0.05). Time to standing in groups DA and MA were not different. Kittens recovered faster than adults after atipamezole. Minimal adverse effects were seen.Conclusions and relevance Atipamezole reliably reduced recovery time after anaesthesia incorporating either dexmedetomidine or medetomidine; however, the choice of dexmedetomidine or medetomidine had little effect. Recovery was faster in kittens.
