2Hawkins,et al.Obstetric anesthesia work force survey,1981 vs1992[J].Anesthesiology,1997,87(2):135-137.
3Burnstein R,et al.A survey of epidural analgesia for labor in the United Kingdon[J].Anaesthesia,1999,54(5):634-637.
4Cleurgue F,et al.French survey of anesthesia in 1996[J].Anesthesiology,1999,91(12):1509-1512.
5Beunard JM,et al.Patient controlled epodural analgesia during labor:the effects of the incrsase in bolus and lockout interva[J].Anasth Analg,2000,90(3):328-329.
6Cohen SE,et al.Walking with labor epidural analgesia he impact of bupivacaine concentration and a lidocaine epinephrine test[J].Anesthesiology,2000,92(2):387-389.
7Morgan BM."Walking" epidurals in labor[J].Anaesthesia,1995,50(8):839-841.
8Collis RE,et al.Colbined spinal epidural anesthesia with baility to walk throughout labor[J].Lanced,1993,341 (12):767-770.
