Frias Adriana F G, Mársico Firmino, Gómez de Segura Ignacio A, Nascimento Paulo R L, Nascimento Amary, Soares Joao H N, Almosny Nadia R
Veterinary School, Fluminense Federal University, Rio de Janeiro, Brazil.
Vet Anaesth Analg. 2003 Oct;30(4):193-201. doi: 10.1046/j.1467-2995.2003.00091.x.
To characterize responses to different doses of propofol in horses pre-medicated with xylazine.
Six adult horses (five females and one male).
Each horse was anaesthetized four times with either ketamine or propofol in random order at 1-week intervals. Horses were pre-medicated with xylazine (1.1 mg kg-1 IV over a minute), and 5 minutes later anaesthesia was induced with either ketamine (2.2 mg kg-1 IV) or propofol (1, 2 and 4 mg kg-1 IV; low, medium and high doses, respectively). Data were collected continuously (electrocardiogram) or after xylazine administration and at 5, 10 and 15 minutes after anaesthetic induction (arterial pressure, respiratory rate, pH, PaO2, PaCO2 and O2 saturation). Anaesthetic induction and recovery were qualitatively and quantitatively assessed.
Differences in the quality of anaesthesia were observed; the low dose of propofol resulted in a poorer anaesthetic induction that was insufficient to allow intubation, whereas the high dose produced an excellent quality of induction, free of excitement. Recorded anaesthesia times were similar between propofol at 2 mg kg-1 and ketamine with prolonged and shorter recovery times after the high and low dose of propofol, respectively (p < 0.05; ketamine, 38 +/- 7 minutes; propofol 1 mg kg-1, 29 +/- 4 minutes; propofol 2 mg kg-1, 37 +/- 5 minutes; propofol 4 mg kg-1, 50 +/- 7 minutes). Times to regain sternal and standing position were longest with the highest dose of propofol (32 +/- 5 and 39 +/- 7 minutes, respectively). Both ketamine and propofol reversed bradycardia, sinoatrial, and atrioventricular blocks produced by xylazine. There were no significant alterations in blood pressure but respiratory rate, and PaO2 and O2 saturation were significantly decreased in all groups (p < 0.05).
The anaesthetic quality produced by the three propofol doses varied; the most desirable effects, which were comparable to those of ketamine, were produced by 2 mg kg-1 propofol.
描述用赛拉嗪预处理的马匹对不同剂量丙泊酚的反应特征。
6匹成年马（5匹雌性和1匹雄性）。
每匹马每隔1周随机用氯胺酮或丙泊酚麻醉4次。马匹用赛拉嗪（1.1毫克/千克静脉注射，1分钟内注射完毕）进行预处理，5分钟后用氯胺酮（2.2毫克/千克静脉注射）或丙泊酚（1、2和4毫克/千克静脉注射；分别为低、中、高剂量）诱导麻醉。连续收集数据（心电图），或在注射赛拉嗪后以及麻醉诱导后5、10和15分钟收集数据（动脉压、呼吸频率、pH值、动脉血氧分压、动脉血二氧化碳分压和血氧饱和度）。对麻醉诱导和苏醒进行定性和定量评估。
观察到麻醉质量存在差异；低剂量丙泊酚导致麻醉诱导较差，不足以进行插管，而高剂量产生了极佳的诱导质量，无兴奋现象。丙泊酚2毫克/千克组与氯胺酮组的记录麻醉时间相似，高剂量和低剂量丙泊酚后的苏醒时间分别延长和缩短（p<0.05；氯胺酮，38±7分钟；丙泊酚1毫克/千克，29±4分钟；丙泊酚2毫克/千克，37±5分钟；丙泊酚4毫克/千克，50±7分钟）。丙泊酚最高剂量时恢复胸骨卧位和站立姿势的时间最长（分别为32±5分钟和39±7分钟）。氯胺酮和丙泊酚均可逆转赛拉嗪引起的心动过缓、窦性和房室传导阻滞。血压无显著变化，但所有组的呼吸频率、动脉血氧分压和血氧饱和度均显著降低（p<0.05）。
三种丙泊酚剂量产生的麻醉质量各不相同；2毫克/千克丙泊酚产生的最理想效果与氯胺酮相当。
