Ca2+ infusion rates during all three protocol versions. Ca2+ infusion rates during all three protocol versions. Data are means ± SD. (A and B) The first two versions have rates every 2 h. The difference between the 0- and 8-h infusion rates in both A and B is statistically significant (P = 0.001 and P = 0.006). (C) The final protocol version had pre- and final infusion rates that were not statistically different. There were no significant differences between the 8-h infusion rates in the first protocol and the final protocol. John A. Clark et al. CJASN 2008;3:736-742 ©2008 by American Society of Nephrology