Hemodynamic Responsiveness to Crystalloid vs Albumin Therapy During VA ECMO

Introduction: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) often relies on volume expansion to maintain circuit flow, but excessive fluid can cause edema and organ dysfunction. Albumin may confer possible mortality benefit over crystalloids, but it’s unclear if the benefit is derived from hemodynamic response or lower net fluid balance. This study aimed to evaluate the hemodynamic response to crystalloid vs albumin boluses in VA-ECMO patients.


Methods: This single-center retrospective cohort study included adult VA-ECMO patients who received crystalloids or albumin within the first 7 days between February 11, 2024, and February 17, 2025. Exclusion criteria were incarceration, pregnancy, overlapping crystalloid and albumin boluses, infusion duration >4 hours, and bolus volumes < 250 mL for albumin or < 500 mL for crystalloids. The primary outcome was the proportion of boluses classified as responders (≥10% increase in MAP or ≥10% reduction in vasopressors) 1-hour post-bolus compared between groups. Secondary outcomes were responder qualifier (MAP or vasopressor), changes in MAP/vasopressor requirements, ICU and hospital length of stay (LOS), in-hospital mortality, ECMO and mechanical ventilation duration, and time from ECMO initiation to bolus. The primary outcome was assessed using the χ2 test and baseline demographics were summarized using counts/percentages and median/IQR.


Results: Final analysis evaluated 51 patients and 179 individual boluses, following exclusion of 31 patients and 32 boluses. Age was 61 (48-68) years, BMI 33.5 (26.8-38.6) kg/m², and 17 (33.3%) patients were female. Response rate was 28.2% (11/39) for crystalloids vs 49.3% (69/140) for albumin (p=0.0192) due to MAP (12.8% vs 37.9%) and vasopressor (20.5% vs 16.4%) response respectively. The duration of ICU LOS was 9.7 (4.2-19.8) days, hospital LOS 17.7 (6.4-28.7) days, ECMO 4.6 (2.6-9.3) days, mechanical ventilation 4.4 (2.3-7.7) days and in-hospital mortality was 56.9%. Time from ECMO initiation to bolus was 15.5 hours (7.8–41.7) vs 24.0 hours (8.7–56.6) for crystalloid and albumin groups respectively.


Conclusions: Albumin was associated with a greater hemodynamic response rate than crystalloids (49.3% vs. 28.2%), which suggests albumin may offer greater short-term MAP improvement in VA-ECMO patients than crystalloids.