Tsukamoto Atsushi, Serizawa Kazuya, Sato Reiichiro, Yamazaki Jumpei, Inomata Tomo
Laboratory of Laboratory Animal Science, Azabu University, School of Veterinary Medicine, 1-17-71 Fuchinobe, Chuou-ku, Sagamihara, Kanagawa 252-5201, Japan.
Exp Anim. 2015;64(1):57-64. doi: 10.1538/expanim.14-0050. Epub 2014 Oct 10.
Selecting the appropriate anesthetic protocol for the individual animal is an essential part of laboratory animal experimentation. The present study compared the characteristics of four anesthetic protocols in mice, focusing on the vital signs. Thirty-two male ddY mice were divided into four groups and administered anesthesia as follows: pentobarbital sodium monoanaesthesia; ketamine and xylazine combined (K/X); medetomidine, midazolam, and butorphanol combined (M/M/B); and isoflurane. In each group, rectal temperature, heart rate, respiratory rate, and O2 saturation (SPO2) were measured, and the changes over time and instability in these signs were compared. The anesthetic depth was also evaluated in each mouse, and the percentage of mice achieving surgical anesthesia was calculated. K/X anesthesia caused remarkable bradycardia, while the respiratory rate and SPO2 were higher than with the others, suggesting a relatively strong cardiac influence and less respiratory depression. The M/M/B group showed a relatively lower heart rate and SPO2, but these abnormalities were rapidly reversed by atipamezole administration. The pentobarbital group showed a lower SPO2, and 62.5% of mice did not reach a surgical anesthetic depth. The isoflurane group showed a marked decrease in respiratory rate compared with the injectable anesthetic groups. However, it had the most stable SPO2 among the groups, suggesting a higher tidal volume. The isoflurane group also showed the highest heart rate during anesthesia. In conclusion, the present study showed the cardiorespiratory characteristics of various anesthetic protocols, providing basic information for selecting an appropriate anesthetic for individual animals during experimentation.
为每只动物选择合适的麻醉方案是实验动物实验的重要组成部分。本研究比较了四种麻醉方案在小鼠中的特点，重点关注生命体征。将32只雄性ddY小鼠分为四组，并给予如下麻醉：戊巴比妥钠单一麻醉；氯胺酮和赛拉嗪联合使用（K/X）；美托咪定、咪达唑仑和布托啡诺联合使用（M/M/B）；以及异氟烷。在每组中，测量直肠温度、心率、呼吸频率和血氧饱和度（SPO2），并比较这些体征随时间的变化和不稳定性。还对每只小鼠的麻醉深度进行了评估，并计算了达到手术麻醉的小鼠百分比。K/X麻醉导致显著的心动过缓，而呼吸频率和SPO2高于其他组，表明对心脏的影响相对较强，呼吸抑制较轻。M/M/B组的心率和SPO2相对较低，但这些异常通过给予阿替美唑迅速得到逆转。戊巴比妥组SPO2较低，62.5%的小鼠未达到手术麻醉深度。与注射麻醉组相比，异氟烷组的呼吸频率显著降低。然而，它在各组中SPO2最稳定，表明潮气量较高。异氟烷组在麻醉期间心率也最高。总之，本研究显示了各种麻醉方案的心肺特征，为实验期间为个体动物选择合适的麻醉提供了基本信息。
