ABSTRACT 452

Abstract

Background and aims: Extracorporeal membrane oxygenation (ECMO) provides lifesaving temporary cardiovascular and/or respiratory support in critically ill patients. The use of ECMO has been rapidly increasing worldwide. However, life-threatening bleeding remains a major complication with ECMO. Acquired von Willebrand disease (VWD) type 2A, a bleeding diathesis with loss of large VWF multimers, has been reported in small adult ECMO case series. Increased consumption of large VWF multimers is postulated as a cause. Larger VWF multimers have more hemostatic function compared to smaller multimers. Aims: The aim of this study was to perform VWF multimeric analyses in pediatric ECMO patients. Methods: Plasma samples of pediatric patients on ECMO were collected from a single center. We performed VWF multimeric analyses by gel electrophoresis and calculated the percentage of large plasma VWF multimers by using radio optical densitometry. We defined the large multimers as the multimeric bands above the 3 smallest molecular weight bands. Results: We analyzed plasma from 35 patients on days 1 and 5 of ECMO and 10 healthy controls. Percentage of large VWF multimers were significantly higher in controls (99%, 94–104) than in pediatric ECMO patients on both d1 (72%, 61–80) and d5 (64%, 46–72) (p<0.05) (median, interquartile range). Percentage of large plasma VWF multimers were significantly higher in pediatric ECMO patients on d1 compared to d5 (p<0.05). Conclusions: In conclusion, pediatric patients on ECMO had loss of large VWF multimers consistent with type 2A acquired VWD. The loss of large VWF multimers worsened over time on ECMO support. Ongoing analyses of this finding could provide further insight. Further studies are warranted.