6Cork RC,et al.Fentanyl preloading for rapid sequence induction of anesthesia. Anesthesia and Analgesia . 1984
7Chari P,Ghai B.Comparison of butorphanol and thiopentone vs fentanyl and thiopentone for laryngeal mask airway inser-tion. Journal of Clinical Anesthesia . 2006
8Bloor BC,Finande E,Flacke WE,et al.Effect of clonidine on sympothoadrenal response during sodium nitroprussideinduced hypotension. Anesthesia and Analgesia . 1986
8Zalunardo MP, Zollinger A, Spahn DR, et al. Effects of intravenous and oral clonidine on hemodynamic and plasma-catecholamine response due to endotracheal intubation. J Clin Anesth, 1997,9:143-147.
9Imai Y, Mammoto T, Murakami K, et al. The effects of preanesthetic oral clonidine on total requirement of propofol for general anesthesia. J Clin Anesth, 1998,10: 660-665.