Department of Clinical Veterinary Sciences, Vetsuisse Faculty, University of Berne, Längassstrasse 124, 3012, Berne, Switzerland.
Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
Acta Vet Scand. 2018 Sep 6;60(1):51. doi: 10.1186/s13028-018-0405-5.
Measurement of invasive blood pressure as reflection of blood flow and tissue perfusion is often carried out in animals during general anesthesia. Intravascular cannulation offers the potential for gas to directly enter the circulation and lead to arterial gas embolism. Cerebral arterial gas embolism may cause a spectrum of adverse effects ranging from very mild symptoms to severe neurological injury and death. Although several experimental models of arterial gas embolism have been published, there are no known published reports of accidental iatrogenic cerebral arterial gas embolism from flushing of an arterial line in animals.
A 7-day-old Red Holstein-Friesian calf (No. 1) and a 28-day-old Holstein-Friesian calf (No. 2) underwent hot iron disbudding and sham disbudding, respectively, under sedation and cornual nerve anesthesia. Invasive arterial blood pressure was measured throughout the procedure and at regular intervals during the day. Before disbudding, a sudden and severe increase of blood pressure was observed following flushing of the arterial line. Excitation, hyperextension of the limbs and rapid severe horizontal nystagmus appeared shortly thereafter. Over the following minutes, symptoms ameliorated and blood pressure normalized in both cases. Prompt diagnosis was missed in calf 1; supportive fluid therapy was provided. Severe deterioration of neurologic status occurred in the following 24 h and culminated with stupor. The calf was euthanized for ethical reasons and the histological examination revealed extensive cerebral injury. Treatment of calf 2 consisted of supportive fluid and oxygen therapy; furosemide (1 mg/kg IV) was injected twice. Calf 2 appeared clinically normal after 2 h and showed no neurologic sequelae on a 3-month-follow up period.
There are no known reports of cerebral arterial gas embolism following flushing of the auricular arterial line in calves. The injection of a small amount of air at high pressure in a peripheral artery may lead to a significant cerebral insult. The clinical presentation is non-specific and can favour misdiagnosis and delay of therapy.
在全身麻醉期间，动物的侵入性血压测量通常用于反映血流和组织灌注。血管内插管可能导致气体直接进入循环，从而导致动脉气体栓塞。脑动脉气体栓塞可能引起一系列不良影响，从非常轻微的症状到严重的神经损伤和死亡。尽管已经发表了几个动脉气体栓塞的实验模型，但目前尚无已知的关于动物动脉线冲洗引起医源性脑动脉气体栓塞的报告。
一头 7 天大的红荷斯坦弗里森小牛（No.1）和一头 28 天大的荷斯坦弗里森小牛（No.2）分别在镇静和角状神经麻醉下接受热铁烧烙和假烧烙。整个过程中以及白天定期测量有创动脉血压。在烧烙前，动脉线冲洗后血压突然剧烈升高。随后不久，出现兴奋、四肢过度伸展和快速严重的水平眼球震颤。在接下来的几分钟内，两例症状均有所缓解，血压恢复正常。No.1 小牛的诊断被延误；提供了支持性液体治疗。在接下来的 24 小时内，神经系统状况严重恶化，并最终出现昏迷。出于伦理原因对该小牛进行安乐死，组织学检查显示广泛的脑损伤。No.2 小牛的治疗包括支持性液体和氧气治疗；静脉注射呋塞米（1mg/kg）两次。2 小时后，该小牛临床状况正常，在 3 个月的随访期内无神经后遗症。
目前尚无已知的在小牛耳部动脉线冲洗后发生脑动脉气体栓塞的报告。在周围动脉高压下注入少量空气可能导致严重的脑损伤。临床表现不特异，可能导致误诊和治疗延误。
