Midodrine for the Treatment of Refractory Hypotension

Persistent hypotension in critically ill patients remains a major barrier to discharging
patients from the intensive care unit (ICU). In our hospital, in patients with adequate
tissue perfusion, midodrine has been observed to treat hypotension in order to wean
continuous intravenous (IV) vasopressors and therefore promote ICU discharge. There are
several possible etiologies of hypotension in the ICU. The most frequently seen causes
include septic shock, hypovolemia, adrenal insufficiency, and idiosyncratic reactions from
medications. For patients whose reversible causes of hypotension have been addressed but
still require vasopressors, midodrine may prove to be a useful adjunctive medication to
successfully increase blood pressure. No previous studies have examined the use of midodrine
for the treatment of hypotension in an ICU setting. Therefore, we are investigating a new
indication for midodrine as the treatment of hypotension in critically ill patients.

Inclusion Criteria:

- At least 18 years of age

- Admitted to the SICU

- Requiring IV vasopressors at a rate of less than 100 mcg/min of phenylephrine or 8
mcg/min of norepinephrine and unable to wean for more than 24 hours while still
maintaining desired blood pressure goal

Exclusion Criteria:

- Inadequate tissue oxygenation (lactate > 1 mmol plus any acute rise in SCr by at
least 0.5 mg/dl within 24 hours, BUN, troponin, bilirubin, LFTs)

- Liver failure (bilirubin > 2 mg/dl, INR > 1.5)

- Hypovolemic shock or hypotension due to adrenal insufficiency

- Recent angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker use

- Midodrine as pre-admission medication

- Any known allergies to midodrine