Optimum spinal anesthesia dose of ropivacaine combined with a single low-dose S-ketamine during elective cesarean delivery: a double-blind sequential study
SUN Yuanqing, XU Tao, ZHANG Xiaoyu, XU Zifeng, CHAI Jing
Journal of Shanghai Jiao Tong University (Medical Science) . 2022, (10): 1428 -1434 .  DOI: 10.3969/j.issn.1674-8115.2022.10.008