Cullen L K, Steffey E P, Bailey C S, Kortz G, da Silva Curiel J, Bellhorn R W, Woliner M J, Elliott A R, Jarvis K A
Department of Surgery, School of Veterinary Medicine, University of California, Davis 95616.
Am J Vet Res. 1990 Feb;51(2):300-4.
The effects of different arterial carbon dioxide tensions (PaCO2) on cerebrospinal fluid pressure (CSFP) and intraocular pressure (IOP) were studied in 6 male halothane-anesthetized horses positioned in left lateral recumbency. Steady-state anesthetic conditions (1.06% end-tidal halothane concentration) commenced 60 minutes following anesthetic induction with only halothane in oxygen. During atracurium neuromuscular blockade, horses were ventilated, and respiratory rate and peak inspiratory airway pressure were maintained within narrow limits. The CSFP and IOP were measured at 3 different levels of PaCO2 (approx 40, 60, and 80 mm of Hg). The PaCO2 sequence in each horse was determined from a type of switchback design with the initial PaCO2 (period 1), established 30 minutes after the commencement of steady-state anesthesia, being repeated in the middle (period 3) and again at the end (period 5) of the experiment. Measurements taken from the middle 3 periods (2, 3, and 4) would form a Latin square design replicated twice. The interval between each period was approximately 45 minutes. Data from periods 2, 3, and 4 indicated that CSFP (P less than 0.05) and mean systemic arterial pressure increased significantly (P less than 0.05) with high PaCO2. Mean central venous pressure, heart rate, and IOP did not change significantly during these same conditions. Measurements taken during periods 1, 3, and 5 were compared to assess the time-related responses to anesthesia and showed a significant increase in CSFP, a significant decrease in mean central venous pressure, and a small (but not statistically significant) increase in mean systemic arterial pressure.
在6匹处于左侧卧的氟烷麻醉雄马中，研究了不同动脉二氧化碳分压（PaCO2）对脑脊液压力（CSFP）和眼内压（IOP）的影响。在仅用氧气中的氟烷诱导麻醉60分钟后开始稳定状态的麻醉条件（呼气末氟烷浓度为1.06%）。在阿曲库铵神经肌肉阻滞期间，对马进行通气，呼吸频率和吸气峰值气道压力保持在狭窄范围内。在3个不同的PaCO2水平（约40、60和80 mmHg）下测量CSFP和IOP。每匹马的PaCO2序列由一种折返设计确定，初始PaCO2（第1期）在稳定状态麻醉开始30分钟后确定，在实验中间（第3期）和结束时（第5期）再次重复。从中间3期（第2、3和4期）获取的测量值将形成重复两次的拉丁方设计。每期之间的间隔约为45分钟。第2、3和4期的数据表明，高PaCO2时CSFP（P<0.05）和平均体动脉压显著升高（P<0.05）。在相同条件下，平均中心静脉压、心率和IOP没有显著变化。比较第1、3和5期的测量值以评估与麻醉相关的时间反应，结果显示CSFP显著升高，平均中心静脉压显著降低，平均体动脉压有小幅升高（但无统计学意义）。
