不同剂量苏芬太尼复合罗哌卡因硬膜外麻醉用于分娩镇痛效果的比较
불동제량소분태니복합라고잡인경막외마취용우분면진통효과적비교
Comparison of different doses of sufentanil and ropivacaine in epidural anesthesia for labor analgesia