Wakuno A, Aoki M, Kushiro A, Mae N, Kodaira K, Maeda T, Yamazaki Y, Ohta M
Racehorse Clinic, Miho Training Center, Japan Racing Association, Inashiki-gun, Ibaraki, Japan.
Equine Vet J. 2017 Jan;49(1):94-98. doi: 10.1111/evj.12548. Epub 2016 Feb 6.
There is limited information on clinical use of the new injectable anaesthetic agent alfaxalone in Thoroughbred horses.
To compare anaesthetic induction and recovery characteristics and cardiopulmonary responses between alfaxalone, ketamine and thiopental in Thoroughbred horses premedicated with medetomidine and midazolam.
Randomised blinded experimental cross-over study.
Six Thoroughbred horses were anaesthetised 3 times with alfaxalone 1 mg/kg bwt, ketamine 2.5 mg/kg bwt or thiopental 4 mg/kg bwt after premedication with medetomidine 6 μg/kg bwt and midazolam 20 μg/kg bwt. Qualities of anaesthetic induction and recovery were scored on a scale of 1 (poor) to 5 (excellent). Induction time and recovery time were recorded. Cardiopulmonary values (heart rate, respiratory rate, arterial blood pressures, and arterial blood gases) were recorded throughout anaesthesia. Data were analysed with nonparametric methods.
The anaesthetic induction (P = 0.2) and recovery (P = 0.1) quality scores (median, range) were not different amongst protocols and were 4.0, 3-5; 5.0, 4-5; 4.5, 3-5; and 4.5, 3-5; 3.5, 2-5; 4.0, 2-5 for alfaxalone, ketamine and thiopental, respectively. Induction time for ketamine (67, 53-89 s) was significantly longer than that for alfaxalone (49, 40-51 s, P = 0.01) and thiopental (48, 43-50 s, P = 0.01). Time to standing for alfaxalone (44, 40-63 min, P = 0.01) and thiopental (39, 30-58 min, P = 0.01) was significantly longer than that for ketamine (25, 18-26 min). Cardiovascular values were maintained within the clinically acceptable level throughout anaesthesia. Respiratory rate significantly decreased during anaesthesia for all 3 drugs; however, spontaneous breathing did not disappear, and PaCO values were maintained at approximately 50 mmHg.
All 3 drugs showed similar effects in relation to anaesthetic induction and recovery qualities and cardiopulmonary responses. However, alfaxalone and thiopental prolonged recovery time compared with ketamine.
关于新型注射用麻醉剂阿法沙龙在纯种马临床应用方面的信息有限。
比较在接受美托咪定和咪达唑仑预处理的纯种马中，阿法沙龙、氯胺酮和硫喷妥钠的麻醉诱导和苏醒特征以及心肺反应。
随机双盲实验交叉研究。
6匹纯种马在接受6μg/kg体重的美托咪定和20μg/kg体重的咪达唑仑预处理后，分别用1mg/kg体重的阿法沙龙、2.5mg/kg体重的氯胺酮或4mg/kg体重的硫喷妥钠进行3次麻醉。麻醉诱导和苏醒质量按1（差）至5（优）评分。记录诱导时间和苏醒时间。在整个麻醉过程中记录心肺参数（心率、呼吸频率、动脉血压和动脉血气）。数据采用非参数方法进行分析。
各方案之间的麻醉诱导（P = 0.2）和苏醒（P = 0.1）质量评分（中位数，范围）无差异，阿法沙龙、氯胺酮和硫喷妥钠的评分分别为4.0，3 - 5；5.0，4 - 5；4.5，3 - 5；4.5，3 - 5；3.5，2 - 5；4.0，2 - 5。氯胺酮的诱导时间（67，53 - 89秒）显著长于阿法沙龙（49，40 - 51秒，P = 0.01）和硫喷妥钠（48，43 - 50秒，P = 0.01）。阿法沙龙（44，40 - 63分钟，P = 0.01）和硫喷妥钠（39，30 - 58分钟，P = 0.01）的站立时间显著长于氯胺酮（(25，18 - 26分钟）。在整个麻醉过程中心血管参数维持在临床可接受水平。所有3种药物在麻醉期间呼吸频率均显著降低；然而，自主呼吸未消失，PaCO值维持在约50mmHg。
所有3种药物在麻醉诱导和苏醒质量以及心肺反应方面显示出相似的效果。然而，与氯胺酮相比，阿法沙龙和硫喷妥钠延长了苏醒时间。
