Taneyama C, Goto H, Kohno N, Benson K T, Sasao J, Arakawa K
Department of Anesthesiology, University of Kansas Medical Center, Kansas City 66160-7415.
Anesth Analg. 1993 Jul;77(1):44-8. doi: 10.1213/00000539-199307000-00009.
The combination of fentanyl and diazepam significantly decreases systemic vascular resistance and blood pressure. We attempted to elucidate the reason the combination of these drugs can reduce blood pressure. In alpha-chloralose-anesthetized dogs, we investigated the effects of fentanyl and diazepam on mean arterial pressure (MAP) and arterial baroreflex control of renal sympathetic nerve activity (RSNA) in both intact (Study 1) and baroreflex-denervated dogs (Study 2). Study 1 included five dogs that received fentanyl 10 micrograms/kg followed by diazepam 0.4 mg/kg after a 10-min interval. Five more received both drugs in reversed sequence. The arterial baroreflex depressor test was performed with sodium nitroprusside before and after administration of each drug. Sensitivity of arterial baroreflex was examined by using the ratio of maximum increase of RSNA to maximum decrease of MAP (delta RSNA/delta MAP). RSNA and MAP significantly decreased only after both drugs had been administered (P < 0.05). Fentanyl alone did not attenuate arterial baroreflex sensitivity. Diazepam after fentanyl and diazepam alone attenuated baroreflex sensitivity to the same extent (P < 0.05). Study 2 comprised 14 dogs that underwent further surgical preparation of bilateral carotid sinus, aortic, and vagal nerve denervations. Seven received fentanyl, 5 and 10 micrograms/kg, and the other seven received diazepam, a total of 0.4 mg/kg. Fentanyl decreased both RSNA and MAP. Diazepam decreased only MAP significantly. The results indicate that fentanyl decreases mainly sympathetic outflow, whereas diazepam attenuates arterial baroreflex. We conclude that these combined effects of fentanyl and diazepam significantly decrease arterial blood pressure.
芬太尼与地西泮联用可显著降低体循环血管阻力和血压。我们试图阐明这两种药物联用能降低血压的原因。在α-氯醛糖麻醉的犬中，我们研究了芬太尼和地西泮对完整犬（研究1）和压力感受性反射去神经犬（研究2）平均动脉压（MAP）以及肾交感神经活动（RSNA）的动脉压力感受性反射控制的影响。研究1包括5只犬，先给予10微克/千克芬太尼，10分钟后再给予0.4毫克/千克地西泮。另外5只犬则按相反顺序给予这两种药物。在每种药物给药前后，用硝普钠进行动脉压力感受性反射降压试验。通过使用RSNA的最大增加量与MAP的最大减少量之比（ΔRSNA/ΔMAP）来检测动脉压力感受性反射的敏感性。仅在两种药物都给药后，RSNA和MAP才显著降低（P<0.05）。单独使用芬太尼并未减弱动脉压力感受性反射敏感性。芬太尼后给予地西泮以及单独给予地西泮，对压力感受性反射敏感性的减弱程度相同（P<0.05）。研究2包括14只犬，这些犬接受了双侧颈动脉窦、主动脉和迷走神经去神经的进一步手术准备。7只犬接受5微克/千克和10微克/千克的芬太尼，另外7只犬接受总共0.4毫克/千克的地西泮。芬太尼可降低RSNA和MAP。地西泮仅显著降低MAP。结果表明，芬太尼主要降低交感神经输出，而地西泮减弱动脉压力感受性反射。我们得出结论，芬太尼和地西泮的这些联合作用可显著降低动脉血压。
