Wessler Benjamin, Madias Christopher, Pandian Natesa, Link Mark S
New England Cardiac Arrhythmia Center, Tufts Medical Center, Boston, MA 02111, USA.
ISRN Cardiol. 2011;2011:582658. doi: 10.5402/2011/582658. Epub 2011 Jun 27.
Background. General anesthesia is an essential element of experimental medical procedures. Ketamine and isoflurane are agents commonly used to induce and maintain anesthesia in animals. The cardiovascular effects of these anesthetic agents are diverse, and the response of global myocardial function is unknown. Methods. In a series of 15 swine, echocardiography measurements of left ventricular ejection fraction (LVEF) were obtained before the animals received anesthesia (baseline), after an intramuscular injection of ketamine (postketamine) and after inhaled isoflurane (postisoflurane). Results. The mean LVEF of an unanesthetized swine was 47 ± 3%. There was a significant decrease in the mean LVEF after administration of ketamine to 41 + 6.5% (P = 0.003). The addition of inhaled isoflurane did not result in further decrease in mean LVEF (mean LVEF 38 ± 7.2%, P = 0.22). Eight of the swine had an increase in their LVEF with sympathetic stimulation. Conclusions. In our experimental model the administration of ketamine was associated with decreased LV function. The decrease may be largely secondary to a blunting of sympathetic tone. The addition of isoflurane to ketamine did not significantly change LV function. A significant number of animals had returned to preanesthesia LV function with sympathetic stimulation.
背景。全身麻醉是实验性医疗程序的一个基本要素。氯胺酮和异氟烷是常用于诱导和维持动物麻醉的药物。这些麻醉剂对心血管的影响是多样的，而对整体心肌功能的反应尚不清楚。方法。在一系列15头猪中，在动物接受麻醉前（基线）、肌肉注射氯胺酮后（氯胺酮后）和吸入异氟烷后（异氟烷后），通过超声心动图测量左心室射血分数（LVEF）。结果。未麻醉猪的平均LVEF为47±3%。注射氯胺酮后，平均LVEF显著下降至41 + 6.5%（P = 0.003）。吸入异氟烷并未导致平均LVEF进一步下降（平均LVEF 38±7.2%，P = 0.22）。8头猪在交感神经刺激下LVEF增加。结论。在我们的实验模型中，氯胺酮的使用与左心室功能下降有关。这种下降可能主要是由于交感神经张力减弱所致。在氯胺酮中加入异氟烷并未显著改变左心室功能。大量动物在交感神经刺激下恢复到麻醉前的左心室功能。
