Hansen T D, Warner D S, Todd M M, Vust L J
Department of Anesthesia, University of Iowa Hospitals and Clinics, Iowa City 52242.
Br J Anaesth. 1989 Sep;63(3):290-5. doi: 10.1093/bja/63.3.290.
Nitrous oxide and halogenated anaesthetic agents are often administered concurrently during neuroanaesthesia. To assess the interactive effects of these agents on cerebral blood flow (CBF), we have measured CBF by 14C-iodoantipyrine autoradiography, in normocapnic rats receiving either 0.5 or 1.0 MAC of volatile agent alone (halothane or isoflurane) or 0.5 MAC of volatile agent + 0.5 MAC nitrous oxide. CBF (global and regional) was significantly greater at 1.0 MAC compared with 0.5 MAC, regardless of how 1.0 MAC was achieved (agent alone or agent + nitrous oxide) (P less than 0.05). The addition of 0.5 MAC nitrous oxide to 0.5 MAC halothane resulted in flows similar to those produced by 1.0 MAC halothane alone. In contrast, the addition of nitrous oxide to 0.5 MAC isoflurane resulted in flow values significantly greater than those measured during 1.0 MAC isoflurane alone. We conclude that the use of nitrous oxide, as opposed to an increased dose of volatile agent, has no advantage in respect of minimizing anaesthetic-induced increases in cerebral blood flow.
在神经麻醉期间，氧化亚氮和卤化麻醉剂常常同时使用。为了评估这些药物对脑血流量（CBF）的交互作用，我们采用14C-碘安替比林放射自显影术，对正常碳酸血症大鼠进行了脑血流量测量。这些大鼠单独接受0.5或1.0 MAC的挥发性药物（氟烷或异氟烷），或0.5 MAC的挥发性药物 + 0.5 MAC氧化亚氮。无论1.0 MAC是如何实现的（单独使用药物或药物 + 氧化亚氮），与0.5 MAC相比，1.0 MAC时的脑血流量（整体和局部）显著更高（P小于0.05）。在0.5 MAC氟烷中加入0.5 MAC氧化亚氮，所产生的血流量与单独使用1.0 MAC氟烷时相似。相比之下，在0.5 MAC异氟烷中加入氧化亚氮，所得到的血流量值显著高于单独使用1.0 MAC异氟烷时所测量的值。我们得出结论，与增加挥发性药物剂量相比，使用氧化亚氮在最小化麻醉诱导的脑血流量增加方面没有优势。
