PEDS9: Bleeding in Pediatric Patients on Extracorporeal Membrane Oxygenation-Use of Procoagulant Factors

Abstract

Background: Bleeding complications remain common in extracorporeal membrane oxygenation (ECMO) and can be associated with adverse outcomes. Effect of excessive shear stress on vasculature may increase bleeding risk associated with preferential loss of high molecular weight von Willebrand factor (high molecular weight (vWF) multimers; acquired vW syndrome, AVWS) and may also be associated with platelet dysfunction. Some pediatric patients may have a pre-existing increased risk of shear-related abnormalities which may further increase bleeding risk on ECMO. We aimed to review bleeding events requiring intervention in a pediatric ECMO cohort. Methods: Retrospective review of pediatric ECMO patients who underwent treatment of bleeding beyond simple transfusion in conjunction with ECMO anticoagulation consultation (EAC) between June 2020 and December 2022 was conducted. Results: Fifty patients required ECMO for 53 runs (52 VA, 2 VV, 1 VAV). Median weight was 4.3 kg (2.4-131 kg). Mean duration of ECMO was 11 days (2-97). 60% (30/50) of patients had congenital heart disease (CHD), and within these 30 patients, 27% of them had bleeding requiring procedural intervention. Ten patients with bleeding were screened for AVWS guided by EAC with 100% meeting criteria for AVWS. Platelet transfusions were administered as first line bleeding therapy with thrombocytopenia or platelet dysfunction and plasma or prothrombin complex concentrate (PCCC) in volume-sensitive patients for coagulopathy. With ongoing bleeding despite transfusion, antihemophilic factor/vWF complex (Humate P) was administered to 4 patients guided by EAC (figure 1). Of these 4 patients, 75% had CHD and 100% had valve abnormalities with 50% having new mechanical valves placed within 1 month prior to ECMO. Initial Humate P dose was given on mean day 14, with mean number of 8 doses. No circuit or mechanical valve thrombosis occurred. Platelet counts and function improved with a decrease in platelet transfusions and clinical bleeding in all patients following Humate P. Conclusion: Bleeding remains a common complication but is often multifactorial and may be difficult to determine specific etiologies. AVWS and thrombocytopenia commonly occur during pediatric ECMO. However, not all patients have clinical bleeding, such that additional risk factors may contribute to increased bleeding risk in these patients. Given impact of recurrent transfusions due to bleeding on morbidity and mortality, as well as cost consideration and potential thrombosis risk of vWF or PCCC supplementation, development of an expert-guided (EAC) algorithm for screening and treatment criteria for such agents appears to be safe, cost-effective and may be associated with decreased bleeding and transfusions. Further research into etiologies and consequences of ECMO-induced bleeding as well as treatment is needed.Figure 1. Algorithm for Assessment of Persistent Bleeding and Consideration of Humate P Administration (pilot).