OBJECTIVES: Shock is a life-threatening condition. It needs immediate management by administering intravenous (IV) fluids and vasopressors. Besides, persistent hypotension delays discharging patients from the intensive care units. Previous studies showed that adjunctive oral midodrine could reduce IV vasopressors therapy duration. However, there is no consensus about the effective and safe doses of midodrine. Our study aims to investigating the efficacy and safety of two different midodrine regimens as adjunctive therapy to IV vasopressors in critically ill patients.

METHODS: A retrospective cohort study including all adult critically ill patients who were administered midodrine as adjunctive therapy from January 2016 to January 2020 were included. Bradycardic and patients who administered midodrine pre-admission medications were excluded. The primary outcome was to compare the impact of the 5 mg and 10 mg three times daily on IV vasopressors duration. Secondary outcomes included investigating the impact of midodrine initiation time on IV vasopressors duration, the impact of different midodrine doses on the length of stay, mean arterial pressure (MAP), heart rate, and mortality.

RESULTS: Midodrine low and high dose groups (N=31,49). The high dose midodrine was associated with 20.55% reduction in ICU days (P<0.001). Similarly, the days of vasopressor therapy were 8.2% less in the high dose but were statistically insignificant (P=0.16). Delayed midodrine initiation was significantly increased vasopressor days (P<0.001), and clinically insignificant (3.6%). Neither midodrine dose nor its initiation time impacted the mortality (P=0.11,0.7). However, MAP significantly increased (8.7 mmHg, P=0.001), but using linear regression, no significant difference was detected between high and low doses (P=0.32). Heart rate not significantly different (P=0.17). No suspected midodrine adverse reactions were detected in the study population.

CONCLUSIONS: In critically ill patients, high dose midodrine seems to reduce the ICU length of stay and IV vasopressor days with an acceptable safety profile.