Double-blind design methud was used in estimating visual analog scale (VAS) and degrc of motor block according to Modified Bromaga Score (MBS) The labor duration,delivery mode,plane of sensation block and Apgar score of neonates were recorded.

• 采用双盲法进行视觉模拟镇痛评分 (VAS)和下肢运动神经阻滞评分 (MBS)。 记录产程时间、生产方式、感觉阻滞平面、新生儿Apgar评分。