RESUMO
Objective: Although heparin is the current standard anticoagulant during venoarterial (VA) and venovenous (VV) extracorporeal membrane oxygenation (ECMO), factors including heparin-induced thrombocytopenia, heparin resistance and drug shortages necessitate alternative anticoagulants such as direct thrombin inhibitors. The aim was to characterize dosing, safety, and efficacy of bivalirudin during ECMO support. Methods: This retrospective single-center study included 24 adults on ECMO support who received ≥6 hours of bivalirudin. The primary endpoint was dose to first therapeutic activated partial thromboplastin time (aPTT). Secondary endpoints included evaluating dosing between ECMO modes, incidence of bleeding and thrombotic events, and time in therapeutic range (TTR). Results: The dose at time of first therapeutic aPTT was bivalirudin 0.05 [0.05-0.1] mg/kg/hour. Bivalirudin dosing requirements were lower in VAECMO compared to VV-ECMO patients and were not impacted by continuous venovenous hemofiltration. Time to therapeutic aPTT was 5.5 [2-13] hours for VA-ECMO and 4.5 [2-8.6] hours for VV-ECMO patients. During any mode of ECMO TTR was 58.3% [39.6-73.1]. Thrombotic events occurred in 3 (13%) patients and major bleeding occurred in 12 (50%) patients. Conclusions: Our findings demonstrated variable bivalirudin dosing requirements based on mode of ECMO and dosing modifications may not be required during CVVH. Factors including mode of ECMO, indication for bivalirudin and concomitant antiplatelet therapy may impact hematologic events. Application of this data can assist with developing a bivalirudin ECMO protocol which provides less variability in initial dosing and TTR.
RESUMO
Background: Immediate-release nifedipine (IRN) is a calcium channel blocker with potent vasodilatory and antihypertensive properties. Safety concerns led to a black box warning for increased risk of myocardial infarction, stroke, and arrhythmias. Objective: The aim of this study was to evaluate the safety and efficacy of IRN for acute blood pressure lowering in critically ill patients. Methods: A retrospective, single-center study was performed in critically ill patients who received at least one dose of IRN. The primary endpoint was the change in systolic blood pressure (SBP) measured at baseline and 1 hour after first administration of IRN. Secondary outcomes included clinically significant hypotension, defined as an absolute reduction in SBP ≥ 15% or vasopressor initiation within 1 hour after administration; incidence of arrhythmias, stroke, or myocardial injury; and time to transition off antihypertensive infusions. Results: IRN resulted in a median [interquartile range] SBP change of -10 [-21 to -1] mmHg between baseline 142 mmHg [124-155] and 1 h post-administration 127 mmHg [114-144]; P < .001. Twenty-seven percent of patients experienced clinically significant hypotension, with hypotension observed in 24% and vasopressors initiated in 4% of patients. Sixteen percent of patients experienced new-onset arrhythmia and 18% experienced myocardial injury following IRN during hospitalization. Median time to transition off intravenous (IV) continuous infusion antihypertensives was 8.5 [0-31.5] hours. Conclusion: IRN led to a reduction in SBP which may have been associated with clinically significant hypotension and need for vasopressor support. Further studies with direct comparisons to alternatives are needed to determine the true association of adverse events with IRN.
