<qa>  What was the statistical power of the sample size calculated using Stata 11?The investigators calculated that a sample size of 354 patients in each group 708 total would be required to detect an absolute reduction in incidence of AKI from 25 current incidence in children with shock in the unit to 15 assuming a two-sided α level of 0.05 and a statistical power of 90. The sample size was calculated using Stata 11. The investigators expect the required sample size to be collected within 3 years period in the three centers. 