Although the primary focus of this pilot study is to determine the feasibility of conducting a clinical outcome based RCT of steroids versus placebo in shock, this pilot also provides an excellent opportunity to perform some exploratory mechanistic studies. These will include 1) comparison of total and free cortisol levels of patients with shock; 2) measurement of stratification biomarkers; and 3) determination of 25 hydroxyvitamin D and 1,25 hydroxyvitamin D levels on admission. Patients with access for blood sampling and for whom consent has been obtained will have blood samples sent for these mechanistic studies.