复合麻醉, 酒石酸溴莫尼定, 氯丙嗪, 体温下降, 心血管动力学

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