【摘要】 目的　探讨地氟醚的交感兴奋作用及其机理。方法　择期手术病人 30例 ,ASAⅠ～Ⅱ级 ,随机分为地氟醚 (15例 )、异氟醚 (15例 )两组。不用术前药。气管插管后观察不同地氟醚和异氟醚水平 (0 .5MAC、1.0MAC和 1.5MAC)对平均动脉压 (MAP)和心率 (HR)、心率变异性 (HRV)和用改良荧光法测定血浆中肾上腺素 (E)、去甲肾上腺素 (NE)浓度的影响。结果　二组MAP、HR、E和NE在麻醉前、0 .5MAC和 1.0MAC时无差异 (P >0 .0 5 ) ,达 1.5MAC后地氟醚组则出现 (2～ 4min的MAP增高和HR增快 ,且血浆E和NE浓度升高 ,明显高于异氟醚组 (P <0 .0 5 ) ,而异氟醚组无变化。HRV的总功率 (TP)、低频 (LF)和高频 (HF)二组都随着MAC的增加逐渐降低 ,但在 1.5MAC时与异氟醚组相比 ,地氟醚组HF明显降低 ,LF/HF明显升高 (P <0 .0 5 )。结论　快速增加地氟醚浓度至1 5MAC可出现交感兴奋作用 ,其作用机制可能是迷走神经受抑制超过交感神经的抑制程度更多还原

【Abstract】 Objective To assess the mechanism of desflurane-mediated sympathetic activation.Methods Thirty patients ASA gradeⅠ-Ⅱ, scheduled for elective surgery under general anesthesia, were randomly divided into two groups : desflurane group (n=15) and isoflurane group (n=15). After tracheal intubation , anesthesia was maintained with 0.5MAC desflurane or isoflurane in oxygen , 15min later, the end-tidal concentration was rapidly increased to 1.0MAC and 1.5MAC , and was kept at either level for 5 min . During the whole procedures, MAP , HR and heart rate variability(HRV) were recorded , and the plasma catecholamine concentrations(E and NE) were determined using the modified fluorimetric assay . Results Compared with those before anesthesia ,MAP,HR and the levels of E and NE had no significant changes at 0.5MAC and 1.0MAC in both groups(P>0.05),but transiently increased only in desflurane group at 1.5MAC (P<0.05) . Total power, low-frequency component(LF) and high-frequency component(HF) of HRV declined with the increase of anesthetic level in both groups ,additionally, in desflurane group HF decreased more significantly , and LF to HF ratio increased more than those in isoflurane group at 1.5MAC (P<0.05).Conclusions A rapid increase in the end-tidal concentration of desflurane to 15MAC can mediate the sympathetic activation due to the more depression of vagal tone than the sympathetic one.更多还原