A retrospective study for association between post‐transfusion hemoglobin S level and pre‐transfusion hemoglobin S level at the next scheduled transfusion

Abstract

AbstractBackgroundPatients with sickle cell disease (SCD) frequently undergo prophylactic red blood cell (RBC) exchange transfusion and simple transfusion (RCE/T) to prevent complications of disease, such as stroke. These treatment procedures are performed with a target hemoglobin S (HbS) of ≤30%, or a goal of maintaining an HbS level of <30% immediately prior to the next transfusion. However, there is a lack of evidence‐based instructions for how to perform RCE/T in a way that will result in an HbS value <30% between treatments.Principal objectiveTo determine whether targets for post‐treatment HbS (post‐HbS) or post‐treatment HCT (post‐HCT) can help to maintain an HbS <30% or <40% between treatments.Materials and methodsWe performed a retrospective study of patients with SCD treated with RCE/T at Montefiore Medical Center from June 2014 to June 2016. The analysis included patients of all ages, and data including 3 documented parameters for each RCE/T event: post‐HbS, post‐HCT, and follow‐up HbS (F/u‐HbS), which is the pre‐treatment HbS prior to the next RCE/T. Generalized linear mixed model was used for estimating the association between post‐HbS or post‐HCT levels and F/u‐HbS <30%.ResultsBased on our results, targeting post‐HbS ≤10% was associated with higher odds of having events of F/u‐HbS <30% between monthly treatments. Targeting post‐HbS ≤15% was associated with higher odds of events of F/u‐HbS < 40%. As compared to post‐HCT ≤30%, a post‐HCT >30%‐36% did not contribute to more F/u‐HbS <30% or HbS <40% events.ConclusionsFor patients with SCD undergoing regular RCE/T for stroke prevention, a post‐HbS ≤10% can be used as a goal to help maintain an HbS <30% for 1 month, and a post‐HbS ≤15% allowed patients to maintain HbS <40%.