Chen Hui C, Sinclair Melissa D, Dyson Doris H
Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada.
Vet Anaesth Analg. 2007 Sep;34(5):301-11. doi: 10.1111/j.1467-2995.2006.00327.x. Epub 2007 May 26.
To determine the cardiovascular responses of ephedrine and dopamine for the management of presurgical hypotension in anesthetized dogs.
Prospective, randomized, clinical trial.
Twelve healthy client-owned dogs admitted for orthopedic surgery; six per group
Prior to surgery, 58 anesthetized dogs were monitored for hypotension [mean arterial pressure (MAP) <60 mmHg] that was not associated with bradycardia or excessive anesthetic depth. Ephedrine (0.2 mg kg(-1), IV) or dopamine (5 microg kg(-1) minute(-1), IV) was randomly assigned for treatment in 12 hypotensive dogs. Ten minutes after the first treatment (Tx(1)-10), ephedrine was repeated or the dopamine infusion rate was doubled. Cardiovascular assessments taken at baseline, Tx(1)-10, and 10 minutes following treatment adjustment (Tx(2)-10) were compared for differences within and between treatments (p < 0.05).
Ephedrine increased cardiac index (CI), stroke volume index (SVI), oxygen delivery index (DO(2)I), and decreased total peripheral resistance (TPR) by Tx(1)-10, while MAP increased transiently (<5 minutes). The second ephedrine bolus produced no further improvement. Dopamine failed to produce significant changes at 5 microg kg(-1) minute(-1), while 10 microg kg(-1) minute(-1) increased MAP, CI, SVI significantly from baseline, and DO(2)I compared with Tx(1)-10. The improvement in CI, SVI, and DO(2)I was not significantly different between treatments at Tx(2)-10.
In anesthetized hypotensive dogs, ephedrine and dopamine improved cardiac output and oxygen delivery. However, the pressure-elevating effect of ephedrine is transient, while an infusion of dopamine at 10 microg kg(-1) minute(-1) improved MAP significantly by additionally maintaining TPR.
确定麻黄碱和多巴胺对麻醉犬术前低血压的心血管反应。
前瞻性、随机临床试验。
12只因骨科手术入院的健康客户拥有的犬；每组6只
手术前，对58只麻醉犬监测与心动过缓或麻醉深度过高无关的低血压[平均动脉压（MAP）<60 mmHg]。12只低血压犬被随机分配接受麻黄碱（0.2 mg kg⁻¹，静脉注射）或多巴胺（5 μg kg⁻¹ 分钟⁻¹，静脉注射）治疗。首次治疗（Tx₁ - 10）10分钟后，重复给予麻黄碱或使多巴胺输注速率加倍。比较在基线、Tx₁ - 10以及治疗调整后10分钟（Tx₂ - 10）时进行的心血管评估，以比较治疗组内和组间的差异（p < 0.05）。
到Tx₁ - 10时，麻黄碱增加了心脏指数（CI）、每搏量指数（SVI）、氧输送指数（DO₂I），并降低了总外周阻力（TPR），而MAP短暂升高（<5分钟）。第二次推注麻黄碱未产生进一步改善。多巴胺在5 μg kg⁻¹ 分钟⁻¹时未产生显著变化，而10 μg kg⁻¹ 分钟⁻¹时MAP、CI、SVI较基线显著升高，且DO₂I与Tx₁ - 10相比有所增加。在Tx₂ - 10时，治疗组间CI、SVI和DO₂I的改善无显著差异。
在麻醉的低血压犬中，麻黄碱和多巴胺改善了心输出量和氧输送。然而，麻黄碱的升压作用是短暂的，而以10 μg kg⁻¹ 分钟⁻¹输注多巴胺通过额外维持TPR显著改善了MAP。
