Lu H, Werner C, Engelhard K, Scholz M, Kochs E
Department of Anesthesiology, Klinikum rechts der Isar, Technische Universität München, Germany.
Anesth Analg. 1998 Oct;87(4):854-8. doi: 10.1097/00000539-199810000-00020.
In this study, we investigated the effect of sevoflurane on cerebral blood flow (CBF) autoregulation in rats. Twenty-four male Sprague-Dawley rats were randomly assigned to receive one of the following anesthetic treatments. In Group 1 (n = 8, control) anesthesia was maintained using fentanyl (25 microg x kg(-1) x h(-1)) and N2O/O2 (fraction of inspired oxygen 0.33). In Group 2 (n = 8) and Group 3 (n = 8), anesthesia was maintained using 2% sevoflurane (1 minimum alveolar anesthetic concentration [MAC]) and 2 MAC sevoflurane (4 vol%) in O2/air (fraction of inspired oxygen 0.33), respectively. Cortical CBF autoregulation was measured during graded hemorrhage within the mean arterial pressure (MAP) range of 100-30 mm Hg using laser Doppler flowmetry. CBF was constant with fentanyl/ N2O (Group 1) and 1 MAC sevoflurane (Group 2) within the MAP range of 100-40 mm Hg. In Group 3 (2 MAC sevoflurane), CBF decreased as a linear function of hemorrhagic hypotension. These results indicate that CBF autoregulation was intact during 1 MAC sevoflurane. In contrast, CBF autoregulation was impaired with 2 MAC sevoflurane. This is probably related to a reduction of baseline cerebrovascular tone with higher concentrations of sevoflurane, which results in a decreased capacity of autoregulatory cerebrovascular dilation during hemorrhage.
The purpose of the present study was to investigate the effect of sevoflurane on cerebral blood flow autoregulation in rats. Cerebral blood flow autoregulation was intact with 1 minimum alveolar anesthetic concentration sevoflurane but was impaired with 2 minimum alveolar anesthetic concentration sevoflurane.
在本研究中，我们调查了七氟醚对大鼠脑血流量（CBF）自动调节的影响。24只雄性Sprague-Dawley大鼠被随机分配接受以下麻醉处理之一。第1组（n = 8，对照组）使用芬太尼（25微克×千克⁻¹×小时⁻¹）和N₂O/O₂（吸入氧分数0.33）维持麻醉。第2组（n = 8）和第3组（n = 8）分别使用2%七氟醚（1个最低肺泡有效浓度[MAC]）和2 MAC七氟醚（4%体积分数）在O₂/空气（吸入氧分数0.33）中维持麻醉。使用激光多普勒血流仪在平均动脉压（MAP）100 - 30毫米汞柱范围内的分级出血过程中测量皮质CBF自动调节。在MAP为100 - 40毫米汞柱范围内，芬太尼/N₂O（第1组）和1 MAC七氟醚（第2组）时CBF保持恒定。在第3组（2 MAC七氟醚）中，CBF随着出血性低血压呈线性下降。这些结果表明在1 MAC七氟醚期间CBF自动调节是完整的。相比之下，2 MAC七氟醚时CBF自动调节受损。这可能与较高浓度七氟醚导致的基线脑血管张力降低有关，这导致出血期间脑血管自动调节性扩张能力下降。
本研究的目的是调查七氟醚对大鼠脑血流量自动调节的影响。1个最低肺泡有效浓度七氟醚时脑血流量自动调节是完整的，但2个最低肺泡有效浓度七氟醚时受损。
