2Gautier P,De Kock M,Van Steenberge,et al. A double -bling comparison of 0. 125% ropivacaine with sufentanil and 0.1250% bupivacaine with sufentanil for epidural analgesia[J]. Anesthesiology, 1999,90 (12) : 772-778.
4Fettes PD. Moore CS. Whiteside JB. et al. Intermittent vs eontinuous administration of epidural ropivacaine with Ientanyl for analgesia during labour[J]. Br J anaesth,2006,97:359- 364.