Licker M, Farinelli C, Klopfenstein C E
Division of Surgical and Anesthesiological Investigations, University Hospital of Geneva, Switzerland.
J Clin Anesth. 1995 Jun;7(4):281-7. doi: 10.1016/0952-8180(95)00025-d.
To determine whether thoracic epidural anesthesia performed prior to general anesthesia provides hemodynamic protection from the stress of laryngoscopy and tracheal intubation; to access the autonomic reflex response to epidural anesthesia, general anesthesia, and airway stimulation.
Randomized unblind, controlled study.
20 elderly (over 60) patients scheduled for colonic or gastric surgery at a university medical center.
All patients (n = 10, in each group) underwent a standardized anesthesia induction sequence that included fentanyl 2 micrograms/kg, thiopental sodium 3 to 5 mg/kg (up to loss of eyelid reflex), and vecuronium 0.1 mg/kg followed by laryngoscopy and tracheal intubation. Before general anesthesia, thoracic epidural anesthesia was performed with plain 1% lidocaine in the epidural group. Preoperatively, baroreflex function was assessed by the Valsalva maneuver and the cough test. Spectral analysis of heart rate (HR) variability was performed before as well as during anesthesia.
There were no differences between the two groups in basal hemodynamics autonomic reflex status. Thoracic epidural anesthesia (median upper level at T2, median lower level at L2) was associated with stable hemodynamics, preservation of baroreflex sensitivity, and increased ratio of low to high frequency (LF/HF) components of HR variability, suggesting withdrawal of vagal activity. In both groups, general anesthesia induction was associated with decreased total HR variability and tracheal intubation was followed by increased LF/HF ratio, reflecting cardiac sympathetic activation. Patients with thoracic epidural anesthesia presented significant attenuation of the maximal rise in mean arterial pressure, and the increase in HR tended to be lower although not significantly.
Thoracic epidural blockade combined with general anesthesia was associated with preserved baroreflex function, and it afforded hemodynamic protection during laryngoscopy and tracheal intubation.
确定在全身麻醉前实施胸段硬膜外麻醉是否能为喉镜检查和气管插管应激提供血流动力学保护；评估硬膜外麻醉、全身麻醉及气道刺激的自主反射反应。
随机非盲对照研究。
20例计划在大学医学中心接受结肠或胃部手术的老年（60岁以上）患者。
所有患者（每组n = 10）均接受标准化麻醉诱导程序，包括静脉注射芬太尼2微克/千克、硫喷妥钠3至5毫克/千克（直至眼睑反射消失）、维库溴铵0.1毫克/千克，随后进行喉镜检查和气管插管。硬膜外麻醉组在全身麻醉前采用单纯1%利多卡因实施胸段硬膜外麻醉。术前通过瓦尔萨尔瓦动作和咳嗽试验评估压力反射功能。在麻醉前及麻醉期间进行心率变异性频谱分析。
两组在基础血流动力学自主反射状态方面无差异。胸段硬膜外麻醉（T2为中位上界，L2为中位下界）与血流动力学稳定、压力反射敏感性保留以及心率变异性低频与高频成分比值（LF/HF）增加有关，提示迷走神经活动减弱。两组中，全身麻醉诱导均与总心率变异性降低有关，气管插管后LF/HF比值增加，反映心脏交感神经激活。接受胸段硬膜外麻醉的患者平均动脉压最大上升幅度明显减弱，心率升高趋势较低，尽管未达显著水平。
胸段硬膜外阻滞联合全身麻醉与压力反射功能保留有关，且在喉镜检查和气管插管期间提供血流动力学保护。
