(142) Droxidopa or Atomoxetine for Refractory Hypotension in Cardiothoracic Surgery ICU Patients

Introduction: Hypotension is common in intensive care unit (ICU) patients, and oral vasopressors may facilitate discharge from the ICU for those requiring intravenous (IV) vasoactive agents. Midodrine is frequently used off-label for ICU patients with refractory hypotension. Droxidopa and atomoxetine are oral vasopressors with limited evidence for use in this population. This study aims to evaluate the effects of droxidopa or atomoxetine on hypotension refractory to midodrine in critically ill cardiothoracic surgery patients.

Methods: A single-center, retrospective cohort study of patients admitted to the Cardiothoracic ICU (CTICU) from Jan 2017 to Aug 2022 who had hypotension refractory to midodrine therapy was performed. Patients were included if they received droxidopa or atomoxetine for at least four consecutive doses and remained on concurrent midodrine therapy. Patients were excluded if they received either study medication before admission, had clinical deterioration after study medication initiation requiring additional vasoactive agents or escalation of IV vasoactive agent dosage for at least 12 hours, had a diagnosis of hepatorenal syndrome, were prisoners, or were pregnant. The primary endpoint was the time to discontinuation of IV vasoactive agents after initiation of study medication. Secondary endpoints included CTICU and hospital length of stay, readmission to the CTICU while on study medication, adverse drug events, and mortality.

Results: A total of 45 patients met the inclusion criteria, of whom 18 received atomoxetine, 17 received droxidopa, and 10 received both study medications. There was no difference in median time to discontinuation of IV vasoactive agents between the groups (12.9 days vs 16.8 days vs 15.4 days, respectively; p=0.709). There was also no difference in ICU or hospital length of stay between groups. A higher percentage of patients who survived to hospital discharge received both study medications or droxidopa alone compared with those who received atomoxetine alone (90% vs 76.5% vs 44.4%, respectively; p=0.028).

Conclusions: There was no difference in median time to discontinuation of IV vasoactive agents or length of stay between atomoxetine, droxidopa, or both medications for the management of refractory hypotension in critically ill cardiothoracic surgery patients.