Borer Kate E, Clarke K W
Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Herts, UK.
Vet Anaesth Analg. 2006 May;33(3):149-57. doi: 10.1111/j.1467-2995.2005.00250.x.
To determine whether hyoscine has a sparing effect on the volume of dobutamine required to maintain mean arterial pressure (MAP) at 70 mmHg in horses anaesthetized with halothane.
Prospective, randomized, controlled clinical trial.
Twenty adult horses weighing 507 +/- 97 kg (mean +/- SD), aged 10 +/- 5 years.
Pre-anaesthetic medication in all horses was intramuscular (IM) acepromazine (40 mug kg(-1)) and intravenous (IV) detomidine (0.02 mg kg(-1)). Anaesthesia was induced with ketamine (2.2 mg kg(-1) IV) and diazepam (0.02 mg kg(-1) IV), and maintained with halothane in oxygen. Horses breathed spontaneously. Flunixin (1.1 mg kg(-1) IV) was given to provide analgesia. Heart rate, ECG, invasive arterial pressure, respiratory rate, percentage end-tidal carbon dioxide, percentage end-tidal halothane and partial pressure of oxygen and carbon dioxide in arterial blood and blood pH were monitored. Dobutamine was infused by an infusion pump to maintain MAP at 70 mmHg. Horses were randomly assigned to receive saline or hyoscine (0.1 mg kg(-1)) IV 30 minutes after induction. The heart rate, MAP and volume of dobutamine infused over 30-minute periods were measured and analysed statistically using a one-way anova.
After administration of hyoscine, heart rate increased for 10 minutes (p < 0.01) and MAP for 5 minutes (p < 0.01). There was no difference in the volume of dobutamine infused over 30 minutes between horses given hyoscine or saline, although there was a wide individual variation in dobutamine requirements. No side effects of hyoscine were seen.
The increase in heart rate and blood pressure that occurs after 0.1 mg kg(-1) hyoscine is given IV in anaesthetized horses, is of short duration and does not significantly alter the amount of dobutamine required to maintain arterial pressure over the next 30 minutes. Clinical relevance The short duration of action of 0.1 mg kg(-1) hyoscine IV may limit its usefulness for correction of hypotension in horses anaesthetized with halothane. Further work is necessary to investigate the effects of higher or repeated doses or constant rate infusions of hyoscine.
确定在氟烷麻醉的马匹中，东莨菪碱对维持平均动脉压（MAP）在70 mmHg所需的多巴酚丁胺用量是否有节省作用。
前瞻性、随机、对照临床试验。
20匹成年马，体重507±97 kg（平均±标准差），年龄10±5岁。
所有马匹麻醉前用药为肌肉注射（IM）乙酰丙嗪（40 μg kg⁻¹）和静脉注射（IV）地托咪定（0.02 mg kg⁻¹）。用氯胺酮（2.2 mg kg⁻¹ IV）和地西泮（0.02 mg kg⁻¹ IV）诱导麻醉，并用氧气中的氟烷维持麻醉。马匹自主呼吸。给予氟尼辛（1.1 mg kg⁻¹ IV）以提供镇痛。监测心率、心电图、有创动脉压、呼吸频率、呼气末二氧化碳百分比、呼气末氟烷百分比以及动脉血中氧和二氧化碳的分压及血液pH值。用输液泵输注多巴酚丁胺以维持MAP在70 mmHg。诱导后30分钟，马匹被随机分配接受静脉注射生理盐水或东莨菪碱（0.1 mg kg⁻¹）。测量30分钟内的心率、MAP和多巴酚丁胺输注量，并使用单因素方差分析进行统计学分析。
给予东莨菪碱后，心率增加10分钟（p < 0.01），MAP增加5分钟（p < 0.01）。给予东莨菪碱或生理盐水的马匹在30分钟内输注的多巴酚丁胺量没有差异，尽管多巴酚丁胺需求量存在很大的个体差异。未观察到东莨菪碱的副作用。
在麻醉马匹中静脉注射0.1 mg kg⁻¹东莨菪碱后出现的心率和血压升高持续时间短，并且在接下来的30分钟内不会显著改变维持动脉压所需的多巴酚丁胺量。临床意义 静脉注射0.1 mg kg⁻¹东莨菪碱的作用持续时间短，可能限制其在氟烷麻醉马匹中纠正低血压的用途。有必要进一步研究更高剂量或重复剂量或持续输注东莨菪碱的效果。
