左旋布比卡因分别复合芬太尼、曲马多用于硬膜外自控镇痛的比较
좌선포비잡인분별복합분태니、곡마다용우경막외자공진통적비교
Comparison of levobupirvacaine combined with fentanyl or tramadol for patient - controlled epidural analgesia