Midodrine as an Adjunctive VasoprEssor for Refractory Hypotension in Intensive Care (MAVERIC) Study

Low blood pressure (hypotension) that does not improve with administration of fluids is a common reason for admission to intensive care. These patients usually require drugs that tighten blood vessels (vasopressor) to be given by continuous drip into a vein (intravenous infusion) to support the circulation and maintain a sage blood pressure for a period of time until the patient improves. Underlying causes of this hypotension may relate to sepsis, inflammatory conditions such as pancreatitis, use of medications and inflammation as sometimes seen in patients after surgery. Midodrine is a drug that tightens blood vessels that can be taken by mouth and has been successfully used in many patients with diseases that cause low blood pressure and faintness when standing (orthostatic hypotension). It can be given as a tablet and is well tolerated. Recent studies have focused on its use in patients with other causes of hypotension and suggest it may be safely used in critically unwell patients already receiving vasopressor infusions for hypotension to shorten the length of time requiring such infusions. This may have additional patient benefits with shorter length of time of invasive monitoring and shorter length of ICU and hospital stay. There are, however, no randomised controlled trials assessing this effect, making it unclear whether reports published so far are correct. We aim to compare the effect of midodrine added to usual care against usual care in critically ill patients on low dose vasopressor infusions for fluid-unresponsive hypotension. We plan to enrol a total of thirty patients who have required a vasopressor infusion for more than 24 hours and remain on an infusion due to continuing hypotension. These thirty patients will be randomly (like the toss of coin) assigned to receive either midodrine in three divided doses of 10 mg each per day or usual care. To understand the effect of the midodrine administration, we will record routinely recorded patient demographic data, circulation data (such as blood pressure, heart rate, central venous pressure and cardiac output), baseline laboratory data (haemoglobin, white cell count, alanine aminotransferase, international normalised ratio, bilirubin, urea, creatinine, troponin, lactate), urine output and fluid balance and dose of intravenous vasopressor. The primary outcome measure will be time in hours from initial administration of Midodrine to cessation of intravenous vasopressor. Secondary outcome measures, such as length of ICU and hospital stay, will also be recorded. The results of this study will provide insight into the effects of midodrine in attenuating duration of vasopressor infusions in intensive care patients with fluid resistant hypotension and, if positive, will allow our patients to be able to stop their infusion and return to the ward and home more quickly.