Inclusion Criteria:  Eligible patients must be admitted to an ICU and must meet all of the following inclusion criteria:  ≥ 18 years of age Refractory hypotension documented within 18 hours prior to enrolment requiring the institution and ongoing use of vasopressor agents (phenylephrine, norepinephrine, vasopressin, epinephrine, midodrine or dopamine >5 mcg/kg/min) at enrolment. Refractory hypotension is defined as a systolic blood pressure (SBP) less than 90 mmHg, or a SBP more than 30 mmHg below baseline, or a mean arterial blood pressure less than 65 mmHg, plus the receipt of ≥ 2 litres of intravenous fluid for the treatment of hypotension.  At least 1 other new organ dysfunction (in addition to refractory hypotension), defined by the following at the time of enrollment:  Creatinine ≥1.5x the known baseline creatinine, or ≥ 26.5 μmol/l increase or <0.5 ml/kg of urine output for 6-12 hours according to the KDIGO (Kidney Disease improving Global Outcomes) guideline definition of acute kidney injury. Need for invasive mechanical ventilation or a P/F ratio <250 Platelets <100 x109/L, or a drop of 50 x109/L in the 3 days prior to enrolment Arterial pH < 7.30 or base deficit > 5 mmol/L in association with a lactate >/= to 4.0 mmol/L  Exclusion Criteria:  We will exclude patients who have any one of the following criteria at the time of enrolment:  Consent declined (refusal from patient, SDM, or physician) Clinically apparent other forms of shock including cardiogenic, obstructive (e.g. massive pulmonary embolism, cardiac tamponade, tension pneumothorax), hemorrhagic, neurogenic, or anaphylactic Received vasopressor therapy for greater than 24 hours prior to enrolment Are currently enrolled in related trial Terminal illness with a life expectancy of less than 3 months Are pregnant