 1. Refractory Hypotension: The patient has received at least 1 litre of normal saline or ringers lactate crystalloid fluid for hypotension defined as a systolic blood pressure less than 90 mm Hg, or a systolic blood pressure more than 40 mm Hg below baseline, or a mean arterial blood pressure less than 65 mm Hg within 8 hours of the first hypotensive event and has refractory hypotension defined by: a Presence of hypotension OR b Initiation of a vasopressor agents. 