Martin-Flores Manuel, Sakai Daniel M, Honkavaara Juhana, Campoy Luis
1 Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
2 Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Finland.
J Feline Med Surg. 2018 Jun;20(6):571-577. doi: 10.1177/1098612X17722265. Epub 2017 Aug 2.
Objectives The objective of this study was to evaluate the cardiovascular effects of low-dose atipamezole administered intravenously to isoflurane-anesthetized cats receiving dexmedetomidine. We hypothesized that atipamezole would increase heart rate (HR) and reduce arterial blood pressure in isoflurane-anesthetized cats receiving dexmedetomidine. Methods Six healthy adult domestic shorthair cats were anesthetized with isoflurane and instrumented for direct arterial pressures and cardiac output (CO) measurements. The cats received a target-controlled infusion of dexmedetomidine (target plasma concentration 10 ng/ml) for 30 mins before administration of atipamezole. Two sequential doses of atipamezole (15 and 30 μg/kg IV) were administered at least 20 mins apart, during dexmedetomidine administration. The effects of dexmedetomidine and each dose of atipamezole on HR, mean arterial blood pressure (MAP), CO and systemic vascular resistance (SVR) were documented. Results Dexmedetomidine reduced the HR by 22%, increased MAP by 78% (both P ⩽0.01), decreased CO by 48% and increased SVR by 58% (both P ⩽0.0003). Administration of atipamezole 15 and 30 μg/kg intravenously increased HR by 8% ( P = 0.006) and 4% ( P = 0.1), respectively. MAP decreased by 39% and 47%, respectively (both P ⩽0.004). Atipamezole 30 μg/kg returned CO and SVR to baseline values. Conclusions and relevance Low doses of atipamezole (15 and 30 μg/kg) administered intravenously to anesthetized cats decreased arterial blood pressure with only marginal increases in HR. Atipamezole 30 μg/kg restored CO and SVR to baseline values before dexmedetomidine administration.
目的 本研究的目的是评估静脉注射低剂量阿替美唑对接受右美托咪定的异氟烷麻醉猫的心血管效应。我们假设阿替美唑会使接受右美托咪定的异氟烷麻醉猫的心率（HR）增加，并降低动脉血压。方法 六只健康成年家养短毛猫用异氟烷麻醉，并安装用于直接测量动脉压和心输出量（CO）的仪器。在给予阿替美唑之前，猫接受右美托咪定的靶控输注（靶血浆浓度10 ng/ml）30分钟。在右美托咪定给药期间，至少间隔20分钟依次给予两剂阿替美唑（15和30 μg/kg静脉注射）。记录右美托咪定和每剂阿替美唑对HR、平均动脉压（MAP）、CO和全身血管阻力（SVR）的影响。结果 右美托咪定使HR降低22%，MAP升高78%（均P⩽0.01），CO降低48%，SVR升高58%（均P⩽0.0003）。静脉注射15和30 μg/kg阿替美唑分别使HR增加8%（P = 0.006）和4%（P = 0.1）。MAP分别降低39%和47%（均P⩽0.004）。30 μg/kg阿替美唑使CO和SVR恢复到基线值。结论及相关性 对麻醉猫静脉注射低剂量阿替美唑（15和30 μg/kg）可降低动脉血压，且HR仅略有增加。30 μg/kg阿替美唑使CO和SVR恢复到右美托咪定给药前的基线值。
