Freye E, Dähn H, Engel M
Abteilung für Zentrale Diagnostik der Rheinischen Landes- und Hochschulklinik in der Universität Essen.
Anasth Intensivther Notfallmed. 1989 Dec;24(6):368-72.
The present study was done in order to investigate the central nervous activity in patients (n = 15) after maxillo-facial surgery, 5 and 90 minutes post ketamine-midazolam-anesthesia. The combination of a benzodiazepine with ketamine was thought to be beneficial to reduce the usual excitatory effects after ketamine postoperatively. In order to demonstrate these benefits EEG-power spectra as well somatosensory-evoked potentials were derived (Neurotrac). Additionally, the central nervous effects were correlated with blood pressure changes. 5 minutes post ketamine-midazolam-anesthesia EEG-power spectra showed a marked depression in the alpha, theta and delta power band when compared to the control-awake situation. However, power in the beta domain (13-30 Hz) was significantly elevated. 90 minutes post anesthesia the high power values returned back to control. In no instance were there any signs of theta-paroxysms which can be taken as an index for central excitation. In the evoked potential a significant increase in amplitude of the early N20 and late N50 peak was evident. This correlated with an increase in systolic blood pressure. 90 minutes post anesthesia only the late N50 peak still remained elevated suggesting some residual excitatory effects in the thalamo-cortical projection area to be present. The latter may reflect an increase in activity in the associative cortical areas of the cerebral cortex. In general however, the additional administration of midazolam resulted in a marked reduction in excitatory central nervous effects when compared to the well known excitation after sole ketamine injection. Thus, the beneficial venture of the two separate classes of anesthetics is advocated for clinical practice.
本研究旨在调查15例颌面部手术后患者在氯胺酮-咪达唑仑麻醉后5分钟和90分钟时的中枢神经活动。苯二氮䓬类药物与氯胺酮联合使用被认为有利于减少氯胺酮术后常见的兴奋作用。为了证明这些益处，我们得出了脑电图功率谱以及体感诱发电位（Neurotrac）。此外，中枢神经效应与血压变化相关。氯胺酮-咪达唑仑麻醉后5分钟，与清醒对照情况相比，脑电图功率谱显示α、θ和δ频段明显抑制。然而，β频段（13 - 30Hz）的功率显著升高。麻醉后90分钟，高功率值恢复到对照水平。在任何情况下都没有出现θ波阵发的迹象，而θ波阵发可作为中枢兴奋的指标。在诱发电位中，早期N20和晚期N50波峰的振幅明显增加。这与收缩压升高相关。麻醉后90分钟，只有晚期N50波峰仍保持升高，表明丘脑-皮质投射区域存在一些残余的兴奋作用。后者可能反映了大脑皮质联合皮质区域活动的增加。然而，总体而言，与单独注射氯胺酮后众所周知的兴奋作用相比，额外给予咪达唑仑导致中枢神经兴奋作用显著降低。因此，提倡在临床实践中联合使用这两类不同的麻醉剂。
