3Vergnion M, Degesves S, Garcetl, et al.Tramadol, an alternative to morphine for Treating posttraumtic pain in the prehospital situation [J] .Analg,2001,92:1543
7Hawkins JL.Epidural analgesia for labor and delivery.N Engl J Med,2010,22:1503-1510.
8Bili N,Djakovi I,Klian-Jai K.Epidural analgesia in labor-controversies.Acta Clin Croat,2015,54:330-336.
9Collis RE,Harding SA,Morgan BM.Effect of maternal ambulation on labour with low-dose combined spinal-epidural analgesia.Anaesthesia,1999,54:535-539.
10Tao W,Grant EN,Craig MG,et al.Continuous Spinal Analgesia for Labor and Delivery:An Observational Study with a 23-Gauge Spinal Catheter,2015,121:1290-1294.