Red blood cell exchange in an emergency in sickle cell disease

Red blood cell exchange (RBCEx) has become a standard therapy to remove abnormal red blood cells (RBCs) in patients with sickle cell disease (SCD). In the last few decades, numerous RBCEx procedures have been performed chronically during regular programs, while numerous procedures have also been performed in an emergency for several indications, this therapeutic option being very efficient in vital and emergency situations. In both groups of indications, large amounts of sickle RBCs have to be removed, which requires great precision and the setting of specific hematological targets. The aim of this review is to discuss the aims, clinical and biological targets, and the requirements and precautions when performing RBCEx in an emergency. Moreover, we analyze how improvement of the techniques as well as the clinical and biological targets has led to optimization of the procedures in emergency settings. We also consider the outstanding issues that require additional investigation.