Oral midodrine treatment accelerates the liberation of intensive care unit patients from intravenous vasopressor infusions

Purpose: Persistent low-level hypotension represents a barrier to discharging patients from the intensive care unit (ICU). Midodrine may be an effective adjunct to wean intravenous (IV) vasopressors and permit ICU discharge. We tested the hypothesis that midodrine, given to patients on IV vasopressors who otherwise met ICU discharge criteria, increased the magnitude of change in IV vasopressor rate.

Materials and methods: This was a prospective, observational study in 20 adult surgical ICU patients who met ICU discharge criteria except for an IV vasopressor requirement. We compared the change in phenylephrine equivalent rates during the day before midodrine to the change in phenylephrine equivalent rates after midodrine initiation and analyzed changes in total body fluid balance, heart rate, mean arterial pressure, and white blood cell count during this period.

Results: Patients received 41.0±33.4 μg/min of phenylephrine equivalents and the change in IV vasopressor rate (slope) decreased significantly from -0.62 μg/min per hour of phenylephrine equivalents before midodrine to -2.20 μg/min per hour following the initiation of midodrine treatment (P=.012). Change in total body fluid balance, heart rate, mean arterial pressure, and white blood cell count did not correlate with change in IV vasopressor rate.

Conclusion: Midodrine treatment was associated with an increase in the magnitude of decline of the IV vasopressor rate. Oral midodrine may facilitate liberation of surgical ICU patients from an IV vasopressor infusion, and this may affect discharge readiness of patients from the ICU.