Parker-Graham Christine A, Lima Kelly M, Soto Esteban
Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616, USA.
Department of Pathology and Laboratory Medicine, University of California, Davis, Davis, CA 95616, USA.
J Zoo Wildl Med. 2020 Mar 17;51(1):102-109. doi: 10.1638/2019-0066.
Anesthesia is commonly employed in aquatic medicine to facilitate physical exams, diagnostics, and surgical interventions. Tricaine methanesulfonate (MS-222) is the most commonly used anesthetic for fish and is currently the only anesthetic approved by the US Food and Drug Administration Center for Veterinary Medicine for food-producing fish. Despite the frequency of anesthetic procedures in fish, anesthetic monitoring remains rudimentary in many facilities. This study evaluated the impact on blood gases, acid-base balance, and electrolytes in koi () anesthetized at concentrations of 100 mg/L and 150 mg/L MS-222. Blood samples from 25 fish per treatment were collected at 5 and 20 min of anesthetic immersion. Forty-nine of 50 fish recovered uneventfully from anesthesia; one fish did not recover and was euthanatized. Results showed significant increases in partial pressure of carbon dioxide (pCO) ( = 0.006) and hyperglycemia ( = <0.0001) with increasing anesthetic concentration and time under anesthesia and a significant decrease in partial pressure of oxygen (pO) with increased anesthetic time ( = 0.021). There were several electrolyte changes observed with both increasing anesthetic time and concentration. All electrolytes except potassium remained within published reference ranges for koi, while potassium showed a significant decrease in concentration associated with anesthetic time and concentration. The results of this study indicate that MS-222 at 100 mg/L and 150 mg/L represent safe anesthetic concentrations for koi undergoing minimally invasive diagnostics; however, koi anesthetized with MS-222 at a concentration of 150 mg/L experienced more significant changes in blood gases, acid-base balance, and electrolyte concentrations.
麻醉在水产医学中通常用于辅助体格检查、诊断和手术干预。甲磺酸三卡因（MS - 222）是鱼类最常用的麻醉剂，也是目前美国食品药品监督管理局兽药中心批准用于食用鱼的唯一麻醉剂。尽管鱼类麻醉操作频繁，但许多机构的麻醉监测仍很初级。本研究评估了在100 mg/L和150 mg/L MS - 222浓度下麻醉锦鲤对血气、酸碱平衡和电解质的影响。每种处理的25条鱼在麻醉浸泡5分钟和20分钟时采集血样。50条鱼中有49条从麻醉中顺利恢复；1条鱼未恢复并实施了安乐死。结果显示，随着麻醉浓度和麻醉时间的增加，二氧化碳分压（pCO₂）显著升高（P = 0.006），血糖显著升高（P = <0.0001），随着麻醉时间增加，氧分压（pO₂）显著降低（P = 0.021）。随着麻醉时间和浓度的增加，观察到几种电解质变化。除钾外，所有电解质均保持在已发表的锦鲤参考范围内，而钾的浓度与麻醉时间和浓度相关显著降低。本研究结果表明，100 mg/L和150 mg/L的MS - 222对接受微创诊断的锦鲤来说是安全的麻醉浓度；然而，用150 mg/L浓度的MS - 222麻醉的锦鲤在血气、酸碱平衡和电解质浓度方面发生了更显著的变化。
