McCarty J E, Trim C M, Ferguson D
Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens 30602.
J Am Vet Med Assoc. 1990 Dec 15;197(12):1646-50.
On 74 occasions, 54 horses and 6 foals were anesthetized with xylazine and ketamine or xylazine, guaifenesin, and ketamine, with or without butorphanol. On 64 occasions, anesthesia was prolonged for up to 70 minutes (34 +/- 15 min) by administration of 1 to 9 supplemental IV injections of xylazine and ketamine at approximately a third the initial dosage. All horses except 5 were positioned in lateral recumbency, and oxygen was insufflated. In adult horses, the time from induction of anesthesia to the first supplemental xylazine and ketamine injection was 13 +/- 4 minutes and the time between supplemental injections was 12.1 +/- 3.7 minutes. These results were consistent with predicted plasma ketamine concentration calculated from previously published pharmacokinetic data for ketamine in horses. Respiratory and heart rates and coccygeal artery pressure remained consistent for the duration of anesthesia. The average interval between the last injection of ketamine and assumption of sternal position was approximately 30 minutes, and was the same regardless of the number of supplemental injections. The time to standing was significantly longer (P less than 0.05) in horses given 2 supplemental injections, compared with those not given any or only given 1, but was not longer in horses given 3 supplemental injections. Recovery was considered unsatisfactory in 5 horses, but did not appear to be related to prolongation of anesthesia.
在74例中，54匹马和6匹驹使用赛拉嗪和氯胺酮或赛拉嗪、愈创甘油醚和氯胺酮进行麻醉，使用或不使用布托啡诺。在64例中，通过以约初始剂量的三分之一静脉补充注射1至9次赛拉嗪和氯胺酮，麻醉时间延长至70分钟（34±15分钟）。除5匹马外，所有马匹均处于侧卧位，并进行氧气吹入。成年马从麻醉诱导到首次补充注射赛拉嗪和氯胺酮的时间为13±4分钟，补充注射之间的时间为12.1±3.7分钟。这些结果与根据先前发表的马匹氯胺酮药代动力学数据计算出的预测血浆氯胺酮浓度一致。在麻醉期间，呼吸、心率和尾动脉压保持稳定。最后一次注射氯胺酮到恢复胸卧姿势的平均间隔约为30分钟，且与补充注射次数无关。与未接受补充注射或仅接受1次补充注射的马匹相比，接受2次补充注射的马匹站立时间显著更长（P<0.05），但接受3次补充注射的马匹站立时间并不更长。5匹马的恢复情况被认为不理想，但似乎与麻醉时间延长无关。
