Whitehair K J, Steffey E P, Woliner M J, Willits N H
Veterinary Medical Teaching Hospital, Department of Surgical and Radiological Sciences, Davis, CA, USA.
Am J Vet Res. 1996 Mar;57(3):351-60.
To study the effects of inhalation anesthetic agents on the response of horses to 3 hours of hypoxemia.
Controlled crossover study.
Five healthy adult horses.
Horses were anesthetized twice: once with halothane, and once with isoflurane in O2. Anesthetized horses were positioned in left lateral recumbency. Constant conditions for the study began at 2 hours of anesthesia. A constant agent dose of 1.2 minimum alveolar concentration, PaO2 of 50 +/- 5 mm of Hg, and PaCO2 of 45 +/- 5 mm of Hg were maintained for 3 hours. Circulatory measurements were made at 0.5, 1, 2, and 3 hours of hypoxemia (anesthesia hours 2.5, 3, 4, and 5). Blood was collected from horses for biochemical analyses before anesthesia, within a few minutes after standing, and at 1, 2, 4, and 7 days after anesthesia.
Cardiac index was greater (P = 0.018) during isoflurane than halothane anesthesia. Cardiac index remained constant during the 3 hours of hypoxemia during halothane anesthesia, whereas it decreased from the baseline during isoflurane anesthesia. Marginally nonsignificant P values for an agent difference were detected for arterial O2 content (P = 0.051), and oxygen delivery (P = 0.057). Serum activities of aspartate transaminase (P = 0.050) and sorbitol dehydrogenase (P = 0.017) were higher in halothane-anesthetized horses than in isoflurane-anesthetized horses. Circulatory function was better in hypoxemic horses anesthetized with isoflurane than with halothane. Isoflurane resulted in less muscular injury in hypoxemia horses than did halothane anesthesia. Halothane anesthesia and hypoxemia were associated with hepatic insult.
Isoflurane is better than halothane for hypoxemic horses.
研究吸入麻醉剂对马匹3小时低氧血症反应的影响。
对照交叉研究。
5匹健康成年马。
马匹接受两次麻醉：一次使用氟烷，一次在氧气中使用异氟烷。麻醉后的马处于左侧卧位。研究的恒定条件在麻醉2小时后开始。维持恒定的麻醉剂剂量为1.2最低肺泡浓度、动脉血氧分压（PaO2）为50±5毫米汞柱、动脉血二氧化碳分压（PaCO2）为45±5毫米汞柱，持续3小时。在低氧血症的0.5、1、2和3小时（麻醉后2.5、3、4和5小时）进行循环系统测量。在麻醉前、站立后几分钟内以及麻醉后1、2、4和7天从马身上采集血液进行生化分析。
异氟烷麻醉期间的心指数高于氟烷麻醉期间（P = 0.018）。在氟烷麻醉的3小时低氧血症期间，心指数保持恒定，而异氟烷麻醉期间心指数从基线下降。对于动脉血氧含量（P = 0.051）和氧输送量（P = 0.057），检测到麻醉剂差异的P值略无统计学意义。氟烷麻醉的马血清天冬氨酸转氨酶（P = 0.050）和山梨醇脱氢酶（P = 0.017）的活性高于异氟烷麻醉的马。异氟烷麻醉的低氧血症马匹的循环功能优于氟烷麻醉的马匹。与氟烷麻醉相比，异氟烷在低氧血症马匹中导致的肌肉损伤更少。氟烷麻醉和低氧血症与肝脏损伤有关。
对于低氧血症马匹，异氟烷优于氟烷。
