Objective To develop a compound anesthetic by proportionally combining brimonidine and chlorpromazine, evaluate its anesthetic effects on rabbits via intravenous injection, and conduct a comprehensive assessment of the compound anesthetic. Methods A dose-response screening experiment was conducted to determine the optimal formulation of the brimonidine-chlorpromazine ( BL) compound anesthetic. After administering 1 mL / kg intravenously, the depth and duration of anesthesia were observed in three dose groups of rabbits, and the optimal dose of BL was selected for further experiments. The BL regimen was compared with the dexmedetomidine-chlorpromazine (DL) regimen. Hemodynamic parameters, including blood pressure, heart rate, and body temperature, were monitored during anesthesia. The analgesic effects of both regimens were evaluated based on the animals’ responses and heart rate changes before and after pain stimulation. Additionally, the effect of brimonidine on increasing the pain threshold was assessed using a laser stimulation test. Results In the dose-response screening,both the high-dose group (0. 6 mg / mL brimonidine and 0. 5 mg / mL chlorpromazine) and the mediumdose group ( 0. 4 mg / mL brimonidine and 0. 5 mg / mL chlorpromazine ) exhibited longer anesthesia maintenance times compared to the low-dose group ( 0. 2 mg / mL brimonidine and 0. 5 mg / mL chlorpromazine) , with no significant difference between the high-dose and medium-dose groups. The medium dose was chosen as the optimal dose for BL intravenous anesthesia. The anesthesia induction time for the BL group was ( 2. 4 ± 1. 5) min, and the anesthesia maintenance time was ( 33. 6 ± 5. 8 ) min.During anesthesia, heart rate decreased, while blood pressure remained relatively stable, and body temperature showed a slight decrease at 75 and 90 min, all of which were superior to the corresponding indicators in the DL group. The BL regimen effectively inhibited mild to moderate pain within 20 min of administration. The average percentage increase in pain threshold for the high-dose, medium-dose, low dose, and control groups of brimonidine was ( 81. 43 ± 15. 52 ) %, ( 47. 81 ± 11. 04 ) %, ( 32. 99 ±6. 14) %, and ( 5. 24 ± 6. 80 ) %, respectively. Conclusion The depth and duration of anesthesia provided by the BL regimen are comparable to those of the DL regimen. However, the BL regimen has a lesser impact on cardiovascular dynamics and body temperature and can more effectively suppress mild to moderate pain. Intravenous brimonidine increases the pain threshold in a dose-dependent manner. The brimonidine-chlorpromazine compound anesthetic demonstrates favorable sedative and analgesic properties, making it suitable for surgeries involving mild to moderate pain stimulation.

combined anesthesia, brimonidine tartrate, chlorpromazine, fall in body temperature;cardiovascular dynamics

目的 将溴莫尼定和氯丙嗪按比例配置成复方麻醉剂,研究其静脉注射对兔的麻醉效果,对该复方麻醉剂的效果进行综合评价。 方法 溴莫尼定-氯丙嗪(BL)复方麻醉剂配方筛选实验,1 mL / kg 注射给药后观察 3 个剂量组兔的麻醉深度和时间,选取 BL 最佳剂量,进行后续实验。 将 BL 与右美托咪定-氯丙嗪( DL) 复方麻醉剂进行比较,监测麻醉过程中兔的血压、心率和体温变化,结合疼痛刺激前后动物反应情况和心率变化,比较两种麻醉方案的镇痛效果。 通过激光刺激实验,研究溴莫尼定对动物痛阈的提高效果。 结果筛选实验中,高剂量组( 0. 6 mg / mL 溴莫尼定和 0. 5 mg / mL 氯丙嗪)和中剂量组(0. 4 mg / mL 溴莫尼定和 0. 5 mg / mL 氯丙嗪) 均比低剂量组( 0. 2 mg / mL溴莫尼定和 0. 5 mg / mL 氯丙嗪)的麻醉维持时间长,而高剂量组和中剂量组的麻醉维持时间无显著性差异。 选择中剂量为 BL 静脉麻醉的最佳剂量,BL 组的麻醉诱导时间为(2. 4±1. 5) min,麻醉维持时间为( 33. 6±5. 8) min,麻醉过程中心率下降,血压较稳定,体温在 75 和 90 min 时轻度下降,均优于 DL 组的相应指标,BL 方案在给药 20 min 内能有效抑制轻中度疼痛。 溴莫尼定的高剂量镇痛组、中剂量镇痛组、低剂量镇痛组与对照组的平均痛阈提高百分率分别为(81. 43±15. 52) %、(47. 81±11. 04) %、(32. 99±6. 14) %、( 5. 24±6. 80) %。 结论 BL 麻醉方案与 DL 麻醉方案的麻醉深度和维持时间接近,但 BL 方案对心血管动力学和体温的影响更小,能更有效抑制轻中度疼痛。 静脉注射溴莫尼定有提高痛阈的作用,且具有正向的量效关系。 溴莫尼定-氯丙嗪复方麻醉剂的镇静镇痛效果良好,能满足轻中度疼痛刺激的手术需要。

复合麻醉, 酒石酸溴莫尼定, 氯丙嗪, 体温下降, 心血管动力学