七氟烷直接的负性肌力和负性变时作用

Direct negative inotropic and lusitropic effects of sevoflurane.

作者信息

Harkin C P, Pagel P S, Kersten J R, Hettrick D A, Warltier D C

机构信息

Department of Anesthesiology, Medical College of Wisconsin, Milwaukee 53226.

出版信息

Anesthesiology. 1994 Jul;81(1):156-67. doi: 10.1097/00000542-199407000-00022.

DOI:10.1097/00000542-199407000-00022

PMID:8042785

Abstract

BACKGROUND

Volatile anesthetics depress left ventricular mechanical performance during multiple phases of the cardiac cycle. The effects of sevoflurane on systolic and diastolic function have yet to be fully evaluated. This investigation characterized the systemic and coronary hemodynamic, inotropic, and lusitropic actions of sevoflurane in chronically instrumented dogs in the presence and absence of autonomic nervous system (ANS) reflexes.

METHODS

Because ANS activity may influence the actions of volatile anesthetics in vivo, experiments were conducted in both ANS-intact and ANS-blocked animals. Eighteen experiments were performed in nine dogs chronically instrumented for measurement of aortic and left ventricular pressure, rate of change of left ventricular pressure, subendocardial segment length, diastolic coronary blood flow velocity, and cardiac output. The preload recruitable stroke work slope was used to assess myocardial contractility. Diastolic function was evaluated by a time constant of isovolumic relaxation, maximum segment lengthening velocity during rapid ventricular filling, and a regional chamber stiffness constant. Dogs were assigned to receive sevoflurane with or without pharmacologic blockade of the ANS in a random fashion. On separate experimental days, systemic and coronary hemodynamics and left ventricular pressure--segment length diagrams and waveforms were recorded in the conscious state and during sevoflurane anesthesia (1.0, 1.25, 1.5, and 1.75 MAC).

RESULTS

In dogs with intact ANS reflexes, sevoflurane caused significant (P < 0.05) increases in heart rate and dose-related decreases in mean arterial pressure, left ventricular systolic pressure, cardiac output, and diastolic coronary vascular resistance. Sevoflurane also decreased myocardial contractility (preload recruitable stroke work slope 96 +/- 4 in the conscious state to 42 +/- 3 mmHg at 1.75 MAC). Sevoflurane prolonged isovolumic relaxation (time constant of isovolumic relaxation 35 +/- 1 in the conscious state to 51 +/- 3 ms at 1.75 MAC) and decreased rapid ventricular filling (maximum segment lengthening velocity 40.2 +/- 6.0 in the conscious state to 21.8 +/- 3.8 mm.s-1 at 1.75 MAC) without affecting regional chamber stiffness. Sevoflurane caused similar alterations in functional indices of left ventricular systolic and diastolic performance in autonomically blocked dogs.

CONCLUSIONS

Sevoflurane caused direct negative inotropic and lusitropic effects in chronically instrumented dogs with and without ANS blockade.

摘要

背景

挥发性麻醉剂在心动周期的多个阶段会抑制左心室机械性能。七氟醚对收缩和舒张功能的影响尚未得到充分评估。本研究描述了在有和没有自主神经系统（ANS）反射的情况下，七氟醚对慢性植入仪器的犬类的全身和冠状动脉血流动力学、变力性和变时性作用。

方法

由于ANS活动可能会影响挥发性麻醉剂在体内的作用，因此在完整ANS和阻断ANS的动物中都进行了实验。对9只慢性植入仪器以测量主动脉和左心室压力、左心室压力变化率、心内膜下节段长度、舒张期冠状动脉血流速度和心输出量的犬进行了18次实验。用可募集的前负荷每搏功斜率来评估心肌收缩力。通过等容舒张时间常数、快速心室充盈期间的最大节段延长速度和局部腔室硬度常数来评估舒张功能。犬被随机分配接受有或没有ANS药理学阻断的七氟醚。在不同的实验日，在清醒状态和七氟醚麻醉（1.0、1.25、1.5和1.75 MAC）期间记录全身和冠状动脉血流动力学以及左心室压力-节段长度图和波形。

结果

在具有完整ANS反射的犬中，七氟醚导致心率显著增加（P < 0.05），并导致平均动脉压、左心室收缩压、心输出量和舒张期冠状动脉血管阻力与剂量相关的降低。七氟醚还降低了心肌收缩力（可募集的前负荷每搏功斜率在清醒状态下为96±4，在1.75 MAC时为42±3 mmHg）。七氟醚延长了等容舒张时间（等容舒张时间常数在清醒状态下为35±1，在1.75 MAC时为51±），并降低了快速心室充盈（最大节段延长速度在清醒状态下为40.2±6.0，在1.75 MAC时为21.8±3.8 mm·s-1），而不影响局部腔室硬度。七氟醚在自主神经阻断的犬中对左心室收缩和舒张性能的功能指标产生了类似的改变。