Effects of different calcium supplementation pathways on calcium ion in calcium-free regional citrate anticoagulation-continuous renal replacement therapy: study protocol for a prospective randomized cross-over trial 
Jiang Biantong, Zhang Zhigang, Jin Xiu, Wang Haiye, Wu Yuchen, Zhang Caiyun
Chinese Journal of Tissue Engineering Research . 2020, (5): 726 -730 .  DOI: 10.3969/j.issn.2095-4344.1921