Shibata K, Taki Y, Futagami A, Yamamoto K, Kobayashi T
Department of Anesthesiology and Intensive Care Medicine, Kanazawa University School of Medicine, Japan.
Acta Anaesthesiol Scand. 1995 Aug;39(6):748-53. doi: 10.1111/j.1399-6576.1995.tb04164.x.
Hypoxia is a critical and sometimes fatal complication of anesthesia. Since there is little information on the cardiovascular response to hypoxia during epidural anesthesia, we assessed the effects of epidural anesthesia on the cardiovascular response to hypoxia and on survival in dogs. We randomly assigned 36 mongrel dogs to one of three groups according to the anesthetic technique used: the thoracic group (n = 12) received thoracic epidural anesthesia plus general anesthesia, the thoracolumbar group (n = 12) received thoracolumbar epidural anesthesia plus general anesthesia, and the control group (n = 12) received general anesthesia alone. We monitored hemodynamics and plasma catecholamine concentrations and assessed survival in these groups during normocapnic hypoxia (FiO2, 0.09 for 120 min). During hypoxic challenge, PaCO2 and PaO2 values were similar in all groups. In both groups that received epidural anesthesia, heart rate, systolic and diastolic arterial pressures, and plasma epinephrine and norepinephrine concentrations were lower and arterial pH was greater than in the control group. There was no significant difference in survival among groups. Epidural anesthesia modified both the physiologic cardiovascular and catecholamine responses to hypoxia. Epidural anesthesia of the thoracic region did not appear to accelerate cardiac arrest, but it attenuated the development of metabolic acidosis during hypoxia.
缺氧是麻醉过程中一种严重且有时致命的并发症。由于关于硬膜外麻醉期间心血管对缺氧反应的信息较少，我们评估了硬膜外麻醉对犬类心血管对缺氧反应及生存情况的影响。根据所采用的麻醉技术，我们将36只杂种犬随机分为三组：胸段组（n = 12）接受胸段硬膜外麻醉加全身麻醉，胸腰段组（n = 12）接受胸腰段硬膜外麻醉加全身麻醉，对照组（n = 12）仅接受全身麻醉。在等碳酸血症性缺氧（吸入氧分数为0.09，持续120分钟）期间，我们监测了血流动力学和血浆儿茶酚胺浓度，并评估了这些组的生存情况。在缺氧挑战期间，所有组的动脉血二氧化碳分压和动脉血氧分压值相似。在接受硬膜外麻醉的两组中，心率、收缩压和舒张压、血浆肾上腺素和去甲肾上腺素浓度均低于对照组，且动脉血pH值高于对照组。各组之间的生存率无显著差异。硬膜外麻醉改变了心血管和儿茶酚胺对缺氧的生理反应。胸段硬膜外麻醉似乎并未加速心脏骤停，但它减轻了缺氧期间代谢性酸中毒的发展。
