The EC90 of remifentanil for inhibiting endotracheal intubation responses under anesthesia induction with ciprofol: study protocol for a dose-finding trial with the biased-coin design. - Guo, Jianing; Xu, Fangsheng; Li, Luoyun; Zhang, Zeru; Xing, Baichun; Fan, Qin; Wang, Zehua; Li, Chunyu (Trials, 2024)