(a) Respiratory failure requiring invasive mechanical ventilation with an expected duration >24 hours (b) Shock of any etiology. Shock is defined by the need for one of the following vasopressors/inotropes: (i) Dopamine ≥7.5 mcg/kg/min (ii) Dobutamine ≥5 mcg/kg/min (iii) Norepinephrine ≥5 mcg/min (iv) Phenylephrine ≥75 mcg/min (v) Epinephrine at any dose (vi) Milrinone at any dose (if used in conjunction with another agent) (vii) Vasopressin ≥0.03 u/min(if used in conjunction with another agent)