Mosley Craig A E, Dyson Doris, Smith Dale A
Department of Clinical Studies, University of Guelph, Guelph, Ontario, Canada.
Vet Anaesth Analg. 2004 Jan;31(1):64-72. doi: 10.1111/j.1467-2995.2004.00135.x.
To assess the cardiovascular effects (arterial blood pressure, heart rate, and metabolic acid-base status) of three doses (MAC multiples) of isoflurane alone and combined with butorphanol in the green iguana (Iguana iguana).
Prospective randomized double-blind, two-period cross-over trial.
Six mature healthy green iguanas (Iguana iguana).
The iguanas received each of two treatments, saline 0.1 mL kg(-1) (SAL) and butorphanol 1.0 mg kg(-1) (BUT) during isoflurane anesthesia. Treatments were separated by at least 1 week. The iguanas were exposed to each of the three minimum alveolar concentration (MAC) multiples (1.0, 1.5, and 2.0) in random order. Anesthesia was induced with isoflurane and maintained using controlled ventilation. Instrumentation included use of an ECG, airway gas monitor, cloacal thermometer, esophageal pulse oximeter, and the placement of a femoral arterial catheter. Body temperature was stabilized and maintained at 32 degrees C. The treatment was administered, and the animals were equilibrated for 20 minutes at each MAC multiple. At each concentration, the heart rate, blood pressure (systolic, mean, diastolic), end-tidal CO2, and SpO2 were measured. At 1.0 and 2.0 MAC, simultaneous blood samples were drawn from the tail vein/artery complex and femoral catheter for blood gas analysis. Data were analyzed using a two-way analysis of variance for repeated measures looking for differences between treatments and among MAC multiples.
There were no significant differences in any of the cardiovascular variables between the treatments. Significant differences among isoflurane MAC multiples were observed for HR, mean, diastolic, and systolic blood pressures. Blood pressure and heart rate decreased with an increasing dose of anesthetic. There were no significant differences between treatments or MAC multiples for any of the blood gas variables. The blood pH, PCO2, HCO3-, and hemoglobin saturation differed significantly between sites. Pulse oximetry values measured from the carotid complex did not correlate with and were significantly different from the calculated hemoglobin saturation values determined using the gas analyzer.
Cardiovascular depression associated with isoflurane anesthesia in the green iguana is dose dependent. The degree of cardiovascular depression was not significantly different when isoflurane was combined with butorphanol. This finding suggests that the pre-emptive or intraoperative use of butorphanol is unlikely to be detrimental to cardiovascular function. Butorphanol may be a useful anesthetic adjunct to isoflurane anesthesia in the green iguana.
评估单独使用三种剂量（最低肺泡有效浓度倍数）的异氟烷以及异氟烷与布托啡诺联用对绿鬣蜥（Iguana iguana）心血管系统的影响（动脉血压、心率和代谢性酸碱状态）。
前瞻性随机双盲、两阶段交叉试验。
六只成熟健康的绿鬣蜥（Iguana iguana）。
在异氟烷麻醉期间，鬣蜥接受两种处理，即0.1 mL kg⁻¹的生理盐水（SAL）和1.0 mg kg⁻¹的布托啡诺（BUT）。处理之间至少间隔1周。鬣蜥以随机顺序接受三种最低肺泡有效浓度（MAC）倍数（1.0、1.5和2.0）中的每一种。用异氟烷诱导麻醉并通过控制通气维持。监测仪器包括心电图、气道气体监测仪、泄殖腔温度计、食管脉搏血氧饱和度仪以及股动脉导管的放置。体温稳定并维持在32℃。给予处理后，动物在每个MAC倍数下平衡20分钟。在每个浓度下，测量心率、血压（收缩压、平均压、舒张压）、呼气末二氧化碳和脉搏血氧饱和度。在1.0和2.0 MAC时，同时从尾静脉/动脉复合体和股动脉导管采集血样进行血气分析。使用重复测量的双向方差分析来分析数据，以寻找处理之间以及MAC倍数之间的差异。
处理之间在任何心血管变量上均无显著差异。观察到异氟烷MAC倍数之间在心率、平均压、舒张压和收缩压方面存在显著差异。血压和心率随着麻醉剂量的增加而降低。在任何血气变量的处理或MAC倍数之间均无显著差异。不同部位的血液pH、PCO₂、HCO₃⁻和血红蛋白饱和度存在显著差异。从颈动脉复合体测得的脉搏血氧饱和度值与使用气体分析仪测定的计算血红蛋白饱和度值不相关且有显著差异。
绿鬣蜥中与异氟烷麻醉相关的心血管抑制是剂量依赖性的。异氟烷与布托啡诺联用时心血管抑制程度无显著差异。这一发现表明，预防性或术中使用布托啡诺不太可能对心血管功能有害。布托啡诺可能是绿鬣蜥异氟烷麻醉的一种有用辅助药物。
