• Isovolemic hemodilution red cell exchange (IHD-RCE) can reduce donor red cell requirements when > 4 RBC units per RCE are needed. • IHD-RCE may increase donor red cell requirements in pediatric patients with total blood volumes ≤ 3500mL compared to standard-RCE Chronic red blood cell (RBC) transfusions are essential for sickle cell disease (SCD) management, but the cumulative demand for donor RBCs strains blood supplies and increases risks of iron overload and alloimmunization. Isovolemic hemodilution red cell exchange (IHD-RCE) is a two-step procedure designed to reduce RBC requirements, but its effectiveness remains unclear, particularly in pediatric patients. We conducted a retrospective cohort study of 45 children and young adults with SCD, each receiving standard-RCE followed by IHD-RCE, comparing within-patient RBC utilization between RCE types. Inclusion required ≥6 consecutive standard-RCEs and ≥6 consecutive IHD-RCEs within a year of each other. Across 2,667 RCE procedures, paired analyses demonstrated both standard and IHD-RCE required a median of 1.2 RBC units per liter of total blood volume (TBV; P = .3017). Adjusted analyses showed that IHD-RCE increased RBC requirements for patients with TBV ≤3500mL. Although not statistically significant, IHD-RCE offered modest RBC savings in patients with TBV >4500 mL. Stratified analysis showed IHD-RCE related savings only for patients requiring > 4 RBC units per transfusion before transitioning from standard-RCE to IHD-RCE ( P = .0186). These findings challenge the assumption that IHD-RCE universally reduces donor blood needs. In patients with low TBV or RBC needs, IHD-RCE does not reduce, and may even increase RBC utilization. Our findings underscore the importance of individualized transfusion strategies, especially during growth and puberty, as not all patients benefit from IHD-RCE.
Dain et al. (Sun,) studied this question.