de Vries A, Brearley J C, Taylor P M
Department of Veterinary Medicine, University of Cambridge, Cambridge, UK.
J Vet Pharmacol Ther. 2009 Aug;32(4):353-8. doi: 10.1111/j.1365-2885.2008.01051.x.
Volatile agent-induced hypotension may contribute to anaesthetic-related morbidity and mortality in horses. Dobutamine is commonly used to support arterial blood pressure (ABP) but little is known about its cardiovascular effects under clinical conditions. The aim of this clinical study was to elucidate the relationship between cardiovascular function and dobutamine infusion in isoflurane-anaesthetized horses. Forty-four horses anaesthetized for a variety of surgical procedures were studied. Premedication with acepromazine, methadone and detomidine was followed by induction of anaesthesia with ketamine and midazolam. Anaesthesia was maintained with isoflurane vaporized in oxygen. Routine anaesthetic monitoring was applied and cardiac output was measured by lithium dilution. Dobutamine was infused to maintain mean ABP above 70 mmHg. The relationship between dobutamine infusion rate, heart rate (HR), ABP and cardiac index was investigated immediately prior to (T(0)) and 15 min (T(1)) after dobutamine infusion started, followed at 30 min intervals (T(2), etc.). Arterial blood pressure increased significantly after dobutamine infusion started, HR and cardiac index increased significantly only with dobutamine infusion in combination with surgical stimulus. Although isoflurane decreases blood pressure mainly by vasodilation, dobutamine is an effective treatment for hypotension under clinical conditions in isoflurane-anaesthetized horses. The effect of dobutamine is not directly proportional to dose and surgical stimulus probably contributes to the cardiovascular improvement.
挥发性麻醉剂引起的低血压可能导致马匹麻醉相关的发病率和死亡率。多巴酚丁胺常用于维持动脉血压（ABP），但在临床条件下其心血管效应鲜为人知。本临床研究的目的是阐明异氟烷麻醉马匹心血管功能与多巴酚丁胺输注之间的关系。对44匹因各种外科手术而麻醉的马匹进行了研究。先用乙酰丙嗪、美沙酮和右美托咪定进行术前用药，然后用氯胺酮和咪达唑仑诱导麻醉。用氧气中蒸发的异氟烷维持麻醉。进行常规麻醉监测，并用锂稀释法测量心输出量。输注多巴酚丁胺以维持平均ABP高于70 mmHg。在多巴酚丁胺输注开始前（T(0)）和开始后15分钟（T(1)）立即研究多巴酚丁胺输注速率、心率（HR）、ABP和心脏指数之间的关系，随后每隔30分钟（T(2)等）进行研究。多巴酚丁胺输注开始后动脉血压显著升高，仅在多巴酚丁胺输注与手术刺激联合使用时HR和心脏指数才显著升高。尽管异氟烷主要通过血管舒张降低血压，但多巴酚丁胺是异氟烷麻醉马匹临床条件下低血压的有效治疗方法。多巴酚丁胺的效果与剂量不成正比，手术刺激可能有助于心血管功能的改善。
