Driessen Bernd, Nann Lawrence, Benton Robin, Boston Raymond
Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, Section of Critical Care/Anesthesia, University of Pennsylvania, PA 19348, USA.
Vet Anaesth Analg. 2006 Nov;33(6):356-67. doi: 10.1111/j.1467-2995.2005.00279.x.
To study whether hemodynamic function in horses, particularly mean arterial blood pressure (MAP), is better maintained with sevoflurane than isoflurane, thus requiring less pharmacological support.
Prospective randomized clinical investigation. Animals Thirty-nine racehorses undergoing arthroscopy in lateral recumbency.
Horses were assigned to receive either isoflurane (n = 20) or sevoflurane (n = 19) at 0.9-1.0 minimum alveolar concentration (MAC) for maintenance of anesthesia. Besides routine clinical monitoring, cardiac output (CO) was measured by lithium dilution. Hemodynamic support was prescribed as follows: when MAP decreased to <70 mmHg, patients were to receive infusion of 0.1% dobutamine, which was to be discontinued at MAP >85 mmHg or heart rate >60 beats minute(-1). Statistical analysis of results, given as mean +/- SD, included a clustered regression approach.
Average inhalant anesthetic time [91 +/- 35 (isoflurane group) versus 97 +/- 26 minutes (sevoflurane group)] and dose (in MAC multiples), volume of crystalloid solution infused, and cardiopulmonary parameters including CO were similar in the two groups, except heart rate was 8% higher in isoflurane than sevoflurane horses (p < 0.05). To maintain MAP >70 mmHg, isoflurane horses received dobutamine over a significantly longer period (55 +/- 26 versus 28 +/- 21% of total anesthetic time, p < 0.01) and at a 51% higher dose than sevoflurane horses (41 +/- 19 versus 27 +/- 23 microg kg(-1) MAC hour(-1); p = 0.058), with 14/20 isoflurane animals and only 9/19 sevoflurane horses being infused with dobutamine at >30 microg kg(-1) MAC hour(-1) (p < 0.05). Dobutamine infusion rates were consistently lower in the sevoflurane as compared to the isoflurane group, with differences reaching significance level during the 0-30 minutes (p < 0.01) and 61-90 minutes periods (p < 0.05).
Horses under sevoflurane anesthesia may require less pharmacological support in the form of dobutamine than isoflurane-anesthetized horses. This could be due to less suppression of vasomotor tone.
研究与异氟烷相比，七氟烷是否能更好地维持马的血流动力学功能，尤其是平均动脉血压（MAP），从而减少药物支持。
前瞻性随机临床研究。动物39匹侧卧接受关节镜检查的赛马。
将马分配为接受异氟烷（n = 20）或七氟烷（n = 19），维持麻醉浓度为0.9 - 1.0最低肺泡浓度（MAC）。除常规临床监测外，通过锂稀释法测量心输出量（CO）。血流动力学支持规定如下：当MAP降至<70 mmHg时，患者接受0.1%多巴酚丁胺输注，当MAP>85 mmHg或心率>60次/分钟时停止输注。结果以平均值±标准差表示，采用聚类回归分析方法进行统计分析。
两组的平均吸入麻醉时间[异氟烷组为91±35分钟，七氟烷组为97±26分钟]、剂量（MAC倍数）、输注的晶体液量以及包括CO在内的心肺参数相似，但异氟烷组马的心率比七氟烷组高8%（p < 0.05）。为维持MAP>70 mmHg，异氟烷组马接受多巴酚丁胺输注的时间显著更长（占总麻醉时间的55±26%，而七氟烷组为28±21%，p < 0.01），且剂量比七氟烷组高51%（41±19与27±23微克/千克·MAC·小时；p = 0.058），异氟烷组20匹马中有14匹、七氟烷组19匹马中只有9匹接受>30微克/千克·MAC·小时的多巴酚丁胺输注（p < 0.05）。与异氟烷组相比，七氟烷组的多巴酚丁胺输注速率始终较低，在0 - 30分钟（p < 0.01）和61 - 90分钟期间差异达到显著水平（p < 0.05）。
与异氟烷麻醉的马相比，七氟烷麻醉的马可能需要更少的多巴酚丁胺形式的药物支持。这可能是由于对血管运动张力的抑制作用较小。
