A prehospital protocol for transfusion of low-titer O-positive whole blood in patients with hemorrhagic shock in Los Angeles County: Modeling the risk of hemolytic disease of the fetus and newborn.

Background: The Los Angeles Development and Rapid Operationalization of Prehospital Blood (LA-DROP) pilot will protocolize prehospital administration of low titer O-positive whole blood (LTO + WB) to patients with hemorrhagic shock in Los Angeles County (LAC). We sought to quantify the risk of death from hemolytic disease of the fetus and newborn (HDFN) associated with RhD-negative alloimmunization in females of childbearing potential (FCPs) as a result of LA-DROP.

Study Design And Methods: Retrospective data from LAC EMS databases were used in combination with estimates from published literature to assign probability distributions to each event in the sequence required for a transfusion of LTO + WB to result in a death from HDFN.