553 - Early Vs Late Peaks in Plasma Free Hemoglobin on ECMO and Association with Mortality

Publication Number: 1532.553

Laura K. Stanfel, Baylor College of Medicine, Houston, TX, United States; Katie Brandewie, Cincinnati Children's Hospital Medical Center, Cin, OH, United States; Diana Cabrera-Fernandez, Baylor College of Medicine, Houston, TX, United States; Sameer Thadani, Baylor College of Medicine, Houston, TX, United States; Andrea Ontaneda, Baylor College of Medicine, Houston, TX, United States

Background: Hemolysis, diagnosed by elevated serum plasma free hemoglobin (pfHgb), is a complication of extracorporeal membrane oxygenation (ECMO) and is more common in pediatric patients than adults. In adults, elevated pfHgb has been associated with increased mortality; however, this association remains unexplored in children prescribed ECMO.

Objective: The objective of this project was to assess the correlation between the timing of peak pfHgb and mortality outcomes in pediatric ECMO patients.

Design/Methods: The exposure studied was the timing of peak pfHgb: early defined as pfHgb ≥50 ml/dL during the first 5 days or late defined as pfHgb≥ 50 mg/dL after day 5. Our primary outcome was mortality 30 days after ECMO initiation. This single center retrospective study included children ≤18 years old who received ECMO and were admitted to any of our intensive care units from 1/2020 to 1/2023. Hemolysis was defined by the ELSO Guidelines (pfHgb ≥ 50 mg/dL). We collected pfHgb over the first 14 days of ECMO or until decannulation.

Results: 196 patients were analyzed. The median age was 7 months (IQR 0.0-64.5), the median ECMO duration was 9.5 days (IQR 7.0-17.0) and 37 patients (19%) died by day 30. Univariate analysis showed that a late peak in pfHgb was associated with increased mortality by day 30 [OR: 2.44(1.09-6.04)] while an early peak was not. In a multivariate analysis controlling for sex, ECPR, ECMO complications, and persistent AKI, late peak in pfHgb was not associated with mortality [OR: 2.24 (0.90-6.10)].

Conclusion(s): This study demonstrates an association between late peak pfHgb and mortality in univariate analysis. Further research should investigate the impact of hemolysis (a potentially modifiable factor) on outcomes in children receiving ECMO.