Ferrari Livia, Turrini Giuliano, Rostello Chiara, Guidi Alessia, Casartelli Alessandro, Piaia Alessandro, Sartori Matteo
Laboratory Animal Science Department, GlaxoSmithKline Medicine, Research Centre, Via Fleming 4, 37135, Verona, Italy.
Comp Med. 2005 Jun;55(3):256-64.
We sought to evaluate a new protocol designed to maintain long-term, nonrecovery, surgical anesthesia in Sprague-Dawley rats. In the first phase, two groups of rats were anesthetized with two different dose combinations of Domitor (medetomidine) and Zoletil 100 (tiletamine-zolazepam) to investigate their efficacy in induction of anesthesia. One combination comprised Domitor at 35 microg/kg and Zoletil 100 at 40 mg/kg, whereas the other comprised Domitor at 50 microg/kg and Zoletil 100 at 20 mg/kg. Both combinations effectively induced deep anesthesia and caused no mortality, but the duration of anesthesia differed statistically. In the second phase, we induced anesthesia with both Domitor-Zoletil 100 dose combinations then investigated the possibility of maintaining anesthesia for 5 h by administering Euthatal (pentobarbitone) intra-arterially at 10 mg/kg hourly. Depth of anesthesia, mortality, physiological parameters, blood gas analysis, hematology, clinical chemistry, and postmortem histopathology were recorded. Euthatal provided stable long-term anesthesia with both dose combinations of Domitor-Zoletil 100. Seven of 8 (88%) animals anesthetized with Domitor at 50 microg/kg and Zoletil 100 at 20 mg/kg successfully were maintained under deep anesthesia for 5 h. Higher mortality (36% versus 12%) occurred in group of animals treated with Domitor at 35 microg/kg and Zoletil 100 at 40 mg/kg. This difference may be linked to dose-related respiratory depression, as alterations of arterial gas levels were noted. Our findings suggest that, when long-term nonrecovery anesthesia is required, doses of 50 microg/kg Domitor and 20 mg/kg Zoletil 100 are preferable when given with Euthatal to maintain physiological conditions in animals.
我们试图评估一种旨在使Sprague-Dawley大鼠维持长期、不可逆手术麻醉的新方案。在第一阶段，两组大鼠分别用两种不同剂量组合的多美康（美托咪定）和速眠新100（替来他明-唑拉西泮）进行麻醉，以研究它们诱导麻醉的效果。一种组合是多美康35微克/千克和速眠新100 40毫克/千克，另一种组合是多美康50微克/千克和速眠新100 20毫克/千克。两种组合均有效诱导了深度麻醉且未导致死亡，但麻醉持续时间在统计学上存在差异。在第二阶段，我们用两种多美康-速眠新100剂量组合诱导麻醉，然后研究通过每小时动脉内注射10毫克/千克安乐死（戊巴比妥）维持5小时麻醉的可能性。记录麻醉深度、死亡率、生理参数、血气分析、血液学、临床化学和死后组织病理学情况。安乐死与两种多美康-速眠新100剂量组合均提供了稳定的长期麻醉。8只用50微克/千克多美康和20毫克/千克速眠新100麻醉的动物中有7只（88%）成功维持了5小时的深度麻醉。用35微克/千克多美康和40毫克/千克速眠新100治疗的动物组死亡率更高（36%对12%）。这种差异可能与剂量相关的呼吸抑制有关，因为观察到了动脉血气水平的改变。我们的研究结果表明，当需要长期不可逆麻醉时，将50微克/千克多美康和20毫克/千克速眠新100与安乐死一起使用以维持动物的生理状况更为可取。
