Remifentanil vs. dexmedetomidine for cardiac surgery patients with noninvasive ventilation intolerance: a multicenter randomized controlled trial oleh Guang-wei Hao, Jia-qing Wu, Shen-ji Yu, Kai Liu, Yan Xue, Qian Gong, Rong-cheng Xie, Guo-guang Ma, Ying Su, Jun-yi Hou, Yi-jie zhang, Wen-jun Liu, Wei Li, Guo-wei Tu, Zhe Luo