BACKGROUND: Red cell exchange (RCE) is an important treatment for sickle cell disease (SCD). It is a resource-intensive intervention requiring large volumes of red blood cells (RBC), which are frequently antigen-matched. Efforts to reduce the volume of units transfused, while maintaining treatment efficacy is an important need. This study evaluates the impact of a change to isovolemic hemodilution (IHD)-RCE on RBC utilization in SCD patients at a Canadian center. STUDY DESIGN AND METHODS: Adult SCD patients receiving chronic automated RCE at the Ottawa Hospital were approached for study inclusion. To safely attain a meaningful reduction in transfused RBCs, RCE parameters were individualized for each patient. IHD-RCE was performed only if an estimated reduction in RBC volume of at least 200 mL was expected, with hematocrit not allowed to decrease below 20%. Data were compared in the 6-months before and after the protocol change. RESULTS: Twenty-two adult patients met the criteria for inclusion. There was a net reduction of 107 RBC units after the transition from standard RCE to IHD-RCE (1035 vs. 928 units
-10.3%). The mean number of RBC units transfused per patient decreased by 4.8 (47.0 vs. 42.2 units
p = .01). No difference in target post-RCE hemoglobin S levels was observed. DISCUSSION: In this study IHD-RCE reduced RBC utilization without impacting efficacy or safety, conserving 107 RBC units (an annualized savings of 5,444 CAD). No adverse events due to saline replacement were observed. Increased awareness of the benefits of IHD-RCE through knowledge translation could promote greater uptake.