Schuster C J, Pang D S J
Department of Veterinary Clinical and Diagnostic Sciences, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada.
Lab Anim. 2018 Apr;52(2):142-151. doi: 10.1177/0023677217712539. Epub 2017 Jun 9.
General anaesthesia disrupts thermoregulation in mammals, which can cause hypothermia. Decreases in core body temperature of 1℃ cause significant postoperative complications in humans, and peri-anaesthetic hypothermia in mice increases data variability, which can potentially increase animal use. In rats, the impact of different temperature management strategies on the incidence and severity of hypothermia, and the accuracy of different temperature measurement methods, is unknown. Eighteen adult male and female SD rats were block-randomized to one of three treatment groups: no-warming (NW), limited-warming (LW, heat pad during anaesthesia), and pre-warming (PW, warm air exposure before anaesthesia, followed by heat pad). Anaesthesia (isoflurane) duration was for 40 min. Core body temperature (intra-abdominal telemetric temperature capsule) was recorded during anaesthesia and recovery. During anaesthesia, rectal, skin, and tail temperatures were also recorded. In the PW group, core temperature was maintained during anaesthesia and recovery. By contrast, the NW group was hypothermic (11% temperature decrease) during anaesthesia. The LW group showed a decrease in temperature during recovery. Recovery to sternal recumbency was significantly faster in the PW (125 [70-186] s, P = 0.0003) and the LW (188 [169-420] s, P = 0.04) groups than in the NW group (525 [229-652] s). Rectal temperature underestimated core temperature (bias -0.90℃, 95% limits of agreement -0.1 to 1.9℃). Skin and tail temperatures showed wide 95% limits of agreement, spanning 6 to 15℃, respectively. The novel strategy of PW was effective at maintaining core temperature during and after anaesthesia. Rectal temperature provided an acceptable proxy for core body temperature.
全身麻醉会扰乱哺乳动物的体温调节，进而可能导致体温过低。人体核心体温每下降1℃就会引发严重的术后并发症，而小鼠围麻醉期体温过低会增加数据变异性，这可能会导致实验动物使用量增加。在大鼠中，不同温度管理策略对体温过低的发生率和严重程度的影响，以及不同体温测量方法的准确性尚不清楚。将18只成年雄性和雌性SD大鼠随机分为三个治疗组之一：不保暖组（NW）、有限保暖组（LW，麻醉期间使用加热垫）和预保暖组（PW，麻醉前暴露于暖风中，然后使用加热垫）。麻醉（异氟烷）持续时间为40分钟。在麻醉和恢复期间记录核心体温（腹腔内遥测温度胶囊）。在麻醉期间，还记录直肠、皮肤和尾巴温度。在PW组中，麻醉和恢复期间核心体温保持稳定。相比之下，NW组在麻醉期间体温过低（体温下降11%）。LW组在恢复期间体温下降。PW组（125 [70 - 186] 秒，P = 0.0003）和LW组（188 [169 - 420] 秒，P = 0.04）恢复到胸骨卧位的速度明显快于NW组（525 [229 - 652] 秒）。直肠温度低估了核心体温（偏差 -0.90℃，95%一致性界限为 -0.1至1.9℃）。皮肤和尾巴温度的95%一致性界限较宽，分别为6至15℃。PW这一新颖策略在麻醉期间及之后维持核心体温方面是有效的。直肠温度可作为核心体温的可接受替代指标。
