Introduction: Extracorporeal membrane oxygenation mandates balancing the risk of thromboembolic complications with bleeding. We aimed to evaluate pragmatic anticoagulation regimens during extracorporeal membrane oxygenation and compare thromboembolic and bleeding outcomes. Methods: This retrospective, single-center study reviewed patients on venovenous or venoarterial extracorporeal membrane oxygenation for a minimum of 24 hours over a 5-year period. The primary outcome was composite thromboembolic events per day of extracorporeal membrane oxygenation. Secondary outcomes included composite bleeding complications, percent of measured activated partial thromboplastin times in goal range, and comparing events with therapeutic anticoagulation for the majority of the extracorporeal membrane oxygenation run (>50% of time on extracorporeal membrane oxygenation) versus non-therapeutic anticoagulation (therapeutic anticoagulation <50% of time). Results: For the primary analysis, 100 patients received heparin, 10 received bivalirudin, and 43 were transitioned between heparin and bivalirudin. No significant differences were identified comparing the heparin group to the bivalirudin (RR = 0.427, p = 0.156) or transitioned group (RR = 1.274, p = 0.325). There were no differences in the rate of bleeding events when comparing the heparin group to the bivalirudin (RR = 0.626, p = 0.250) or transitioned group (RR = 0.742, p = 0.116). An increased number of adjustments to the anticoagulants was associated with a statistically higher rate of bleeding events per day (p = 0.006). Conclusion: There were no differences in thromboembolic or bleeding events when comparing different anticoagulant regimens. Adjustments to the anticoagulants are more likely to occur when bleeding is observed. Due to variability in anticoagulation, there is a need to standardize anticoagulation with extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation (ECMO) poses unique thrombotic and hemorrhagic risks, and the optimal anticoagulant choice is unknown. We systematically searched Ovid EBM Reviews, Ovid Embase, Ovid Medline, Scopus, and Web of Science Core Collection for randomized-, crossover-, retrospective cohort-, or parallel-designed clinical studies of adult patients receiving ECMO that compared heparin recipients with bivalirudin recipients. Meta-analysis was performed with random-effects models. The ROBINS-I tool was used to assess the risk of bias. Six retrospective observational studies met the inclusion criteria for the qualitative summary. Five studies were suitable for meta-analysis. Those who received heparin were more likely to experience circuit-related thrombosis (odds ratio [OR] 2.05, 95% confidence interval [CI] 1.25-3.37, p = 0.005, I 2 = 0%) and die (OR 1.62, 95% CI 1.19-2.21, p = 0.002, I 2 = 0%) compared with those who received bivalirudin. There were no differences in major bleeding events between heparin and bivalirudin recipients (OR 1.83, 95% CI 0.55-6.09, p = 0.33, I 2 = 82.7%). In retrospective settings compared with heparin anticoagulation, bivalirudin was associated with less circuit-related thrombotic events and greater survival in adults supported on ECMO, without contributing to more bleeding complications. Prospective controlled studies comparing heparin and bivalirudin in adult ECMO patients are warranted to corroborate these findings.

Objectives: In practice, midodrine has been used to reduce IV vasopressor requirements and decrease ICU length of stay. However, recent publications have failed to show clinical success when midodrine was administered every 8 hours. One possible reason for the lack of clinical efficacy at this dosing interval may be the pharmacokinetic properties of midodrine that support a more frequent dosing interval. Here, we report our institutional experience with midodrine at a dosing frequency of every 6 hours. Design: Single, quaternary academic medical center, retrospective, descriptive study. Setting: Floor and ICU patients admitted to Mayo Clinic, Rochester, from May 7, 2018, to September 30, 2020. Patients: Adult patients with an order for midodrine with a dosing frequency of “every 6 hours” or “four times daily” were eligible for inclusion. Interventions: No intervention performed. All data were abstracted retrospectively from the electronic medical record. Measurements and Main Results: Forty-four unique patients were identified that met inclusion criteria. Patients were an average of 65 years and 63.6% were male. The individual doses of midodrine ranged from 5 to 20 mg. Twenty-three patients (52.3%) were receiving IV vasopressors at the time midodrine was ordered every 6 hours. Vasopressor requirements decreased from an average of 0.10 norepinephrine equivalents 24 hours prior to the every 6-hour order to 0.05 norepinephrine equivalents 24 hours after an order for midodrine every 6 hour was placed. Conclusions: Increasing the dosing frequency of midodrine to every 6 hours may optimize its pharmacokinetic profile without compromising safety. This midodrine dosing frequency should be prospectively evaluated as a primary strategy for accelerated IV vasopressor wean.