Brain and Spinal Injury Center, Department of Neurological Surgery, University of California, San Francisco, California, USA.
J Neurotrauma. 2012 Mar 20;29(5):990-9. doi: 10.1089/neu.2011.1845. Epub 2011 Aug 8.
Anesthetics affect outcomes from central nervous system (CNS) injuries differently. This is the first study to show how two commonly used anesthetics affect continuously recorded hemodynamic parameters and locomotor recovery during a 2-week period after two levels of contusion spinal cord injury (SCI) in rats. We hypothesized that the level of cardiovascular depression and recovery of locomotor function would be dependent upon the anesthetic used during SCI. Thirty-two adult female rats were subjected to a sham, 25-mm or 50-mm SCI at T3-4 under pentobarbital or isoflurane anesthesia. Mean arterial pressure (MAP) and heart rate (HR) were telemetrically recorded before, during, and after SCI. Locomotor function recovered best in the 25-mm-injured isoflurane-anesthetized animals. There was no significant difference in locomotor recovery between the 25-mm-injured pentobarbital-anesthetized animals and the 50-mm-injured isoflurane-anesthetized animals. White matter sparing and extent of intermediolateral cell column loss appeared larger in animals anesthetized with pentobarbital, but this was not significant. There were no differential effects of anesthetics on HR and MAP before SCI, but recovery from anesthesia was significantly slower in pentobarbital-anesthetized animals. At the time of SCI, MAP was acutely elevated in the pentobarbital-anesthetized animals, whereas MAP decreased in the isoflurane-anesthetized animals. Hypotension occurred in the pentobarbital-anesthetized groups and in the 50-mm-injured isoflurane-anesthetized group. In pentobarbital-anesthetized animals, SCI resulted in acute elevation of HR, although HR remained low. Return of HR to baseline was much slower in the pentobarbital-anesthetized animals. Severe SCI at T3 produced significant chronic tachycardia that was injury severity dependent. Although some laboratories monitor blood pressure, HR, and other physiological variables during surgery for SCI, inherently few have monitored cardiovascular function during recovery. This study shows that anesthetics affect hemodynamic parameters differently, which in turn can affect functional outcome measures. This supports the need for a careful evaluation of cardiovascular and other physiological measures in experimental models of SCI. Choice of anesthetic should be an important consideration in experimental designs and data analyses.
麻醉对中枢神经系统（CNS）损伤的结果有不同的影响。这是第一项研究，旨在展示两种常用麻醉剂如何影响大鼠两种挫伤脊髓损伤（SCI）水平后 2 周内连续记录的血流动力学参数和运动功能恢复。我们假设心血管抑制程度和运动功能恢复程度将取决于 SCI 期间使用的麻醉剂。32 只成年雌性大鼠在戊巴比妥或异氟烷麻醉下接受 T3-4 的假手术、25-mm 或 50-mm SCI。在 SCI 之前、期间和之后，通过遥测法记录平均动脉压（MAP）和心率（HR）。在 25-mm 损伤的异氟烷麻醉动物中，运动功能恢复最好。25-mm 损伤的戊巴比妥麻醉动物和 50-mm 损伤的异氟烷麻醉动物之间的运动功能恢复没有显著差异。在戊巴比妥麻醉的动物中，白质保存和中间外侧细胞柱损失程度似乎更大，但这并不显著。麻醉剂对 HR 和 MAP 没有差异影响在 SCI 之前，但戊巴比妥麻醉的动物从麻醉中恢复的速度明显较慢。在 SCI 时，戊巴比妥麻醉的动物中 MAP 急性升高，而异氟烷麻醉的动物中 MAP 降低。在戊巴比妥麻醉组和 50-mm 损伤的异氟烷麻醉组中出现低血压。在戊巴比妥麻醉的动物中，SCI 导致 HR 急性升高，尽管 HR 仍然较低。HR 恢复到基线的速度在戊巴比妥麻醉的动物中要慢得多。T3 处的严重 SCI 导致严重的慢性心动过速，这与损伤严重程度有关。尽管一些实验室在 SCI 手术期间监测血压、HR 和其他生理变量，但很少有实验室在恢复期间监测心血管功能。这项研究表明，麻醉剂对血流动力学参数的影响不同，这反过来又会影响功能测量结果。这支持在 SCI 的实验模型中需要仔细评估心血管和其他生理指标。麻醉剂的选择应该是实验设计和数据分析中的一个重要考虑因素。
