McKenzie Erica C, Di Concetto Stefano, Payton Mark E, Mandsager Ronald E, Arko Matevz
Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331.
Am J Vet Res. 2015 Apr;76(4):293-301. doi: 10.2460/ajvr.76.4.293.
To determine the effect of dantrolene premedication on various cardiovascular and biochemical variables and recovery in isoflurane-anesthetized horses.
6 healthy horses.
Each horse was anesthetized twice with a 21- to 28-day washout period between anesthetic sessions. Food was not withheld from horses before either session. During each session, dantrolene (6 mg/kg in 2 L of water) or water (2 L) was administered via a nasogastric tube 1 hour before anesthesia was induced. Anesthesia was maintained with isoflurane for 90 minutes, during which blood gas analyses and lithium-dilution cardiac output (CO) measurements were obtained every 10 minutes. Serum creatine kinase activity was measured before and at 4, 8, and 12 hours after anesthesia.
When horses were premedicated with dantrolene, CO at 25, 35, and 45 minutes after induction of anesthesia was significantly lower than that when horses were premedicated with water after which time difficulty in obtaining valid measurements suggested a continued decrease in CO; plasma potassium concentration progressively increased during anesthesia, whereas serum creatine kinase activity remained fairly stable and within reference limits through 12 hours after anesthesia; and 2 of 6 horses developed cardiac arrhythmias that required medical intervention. The quality of anesthetic recovery was slightly better when horses were premedicated with dantrolene versus water, although the time required for recovery did not differ significantly between treatments.
Results suggested that dantrolene premedication prevented muscle damage without affecting anesthetic recovery but impaired CO and precipitated hyperkalemia and cardiac arrhythmias in healthy isoflurane-anesthetized horses.
确定丹曲林预处理对异氟烷麻醉马匹的各种心血管和生化指标以及恢复情况的影响。
6匹健康马匹。
每匹马接受两次麻醉，两次麻醉之间有21至28天的洗脱期。在每次麻醉前，马匹不禁食。在每次麻醉过程中，于诱导麻醉前1小时经鼻胃管给予丹曲林（6 mg/kg溶于2 L水中）或水（2 L）。用异氟烷维持麻醉90分钟，在此期间每10分钟进行血气分析和锂稀释法心输出量（CO）测量。在麻醉前以及麻醉后4、8和12小时测量血清肌酸激酶活性。
当马匹用丹曲林预处理时，麻醉诱导后25、35和45分钟时的CO显著低于用水预处理的马匹，此后难以获得有效测量值提示CO持续下降；麻醉期间血浆钾浓度逐渐升高，而血清肌酸激酶活性在麻醉后12小时内保持相当稳定且在参考范围内；6匹马中有2匹出现心律失常，需要药物干预。与用水预处理相比，用丹曲林预处理的马匹麻醉恢复质量略好，尽管两种处理之间恢复所需时间差异不显著。
结果表明，丹曲林预处理可预防肌肉损伤，不影响麻醉恢复，但会损害健康的异氟烷麻醉马匹的CO，引发高钾血症和心律失常。
