Lin H C, Thurmon J C, Tranquilli W J, Benson G J, Olson W A
Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana 61801.
Am J Vet Res. 1991 Oct;52(10):1606-10.
Six healthy Holstein calves were anesthesized with isoflurane in O2 and instrumented for hemodynamic studies. A saphenous artery was catheterized for measurement of blood pressure and withdrawal of blood for determination of the partial pressure of carbon dioxide (PaCO2), oxygen (PaO2), and arterial pH (pHa). Respiration was controlled throughout the study. The ECG and EEG were monitored continuously. A thermodilution catheter was passed via the right jugular vein into the pulmonary artery for determination of cardiac output and measurement of central venous pressure, pulmonary arterial pressure, and pulmonary capillary wedge pressure. Baseline values (time 0) were recorded following recovery from isoflurane. Tiletamine-zolazepam (4 mg/kg)-xylazine (0.1 mg/kg) were administered IV immediately after recording baseline values. Values were again recorded at 5, 10, 20, 30, 40, 50, and 60 minutes after injection. Changes in left ventricular stroke work index, PaCO2, and pHa were insignificant. Arterial blood pressure and systemic vascular resistance increased above baseline at 5 minutes and then gradually decreased below baseline at 40 minutes, demonstrating a biphasic response. Values for pulmonary capillary wedge pressure, pulmonary arterial pressure, central venous pressure, and PaO2 were increased above baseline from 5 to 60 minutes. Stroke volume, stroke index, and right ventricular stroke work index were increased from 20 or 30 minutes to 60 minutes. Pulmonary vascular resistance increased at 10 minutes, returned to baseline at 20 minutes, and was increased again at 60 minutes. Heart rate, cardiac output, cardiac index, and rate pressure product were decreased at 5 minutes, and with the exception of cardiac output, remained so for 60 minutes. Cardiac output returned to the baseline value at 30 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)
六头健康的荷斯坦犊牛用异氟醚在氧气中麻醉，并安装仪器进行血流动力学研究。通过一根大隐动脉插入导管，用于测量血压和采血，以测定二氧化碳分压（PaCO2）、氧分压（PaO2）和动脉血pH值（pHa）。在整个研究过程中控制呼吸。持续监测心电图和脑电图。通过右颈静脉插入一根热稀释导管至肺动脉，用于测定心输出量以及测量中心静脉压、肺动脉压和肺毛细血管楔压。在从异氟醚麻醉中恢复后记录基线值（时间0）。在记录基线值后立即静脉注射替来他明-唑拉西泮（4毫克/千克）-赛拉嗪（0.1毫克/千克）。在注射后5、10、20、30、40、50和60分钟再次记录数值。左心室每搏功指数、PaCO2和pHa的变化不显著。动脉血压和全身血管阻力在5分钟时高于基线水平，然后在40分钟时逐渐降至基线水平以下，呈现双相反应。肺毛细血管楔压、肺动脉压、中心静脉压和PaO2的值在5至60分钟内高于基线水平。每搏量、每搏指数和右心室每搏功指数从20或30分钟至60分钟增加。肺血管阻力在10分钟时增加，在20分钟时恢复到基线水平，并在60分钟时再次增加。心率、心输出量、心脏指数和率压乘积在5分钟时降低，除心输出量外，在60分钟内一直保持降低。心输出量在30分钟时恢复到基线值。（摘要截短至250字）
