417 Early Data From an Out-of-Hospital Whole Blood Transfusion Program for Trauma Patients

Only a few emergency medical services (EMS) systems in the United States currently use whole blood transfusions (WBTs). Given the increasing data supporting the use of WBTs, more EMS systems are likely to consider or begin WBT programs in the future. We recently implemented a prehospital WBT program for trauma patients in Palm Beach County, Florida. We sought to assess the outcomes and frequency of adverse events related to WBT of the initial cohort of patients who received prehospital WBT in our system. This was a retrospective database review of the initial patients who received WBT in our EMS system in Palm Beach County. We started a prehospital WBT program for trauma patients on July 6, 2022. Our current indications for transfusion of low titer, leukoreduced O+ whole blood in the prehospital setting include traumatic injuries with systolic blood pressure < 70 mm Hg or systolic blood pressure < 90 mm Hg plus heart rate > 110 beats per minute. Patients may receive up to 2 units of whole blood. All patients who receive prehospital WBT are tracked in a database for quality assurance purposes. We abstracted the following data points from this database: demographic information, means of transport, vital signs, prehospital therapies, and mortality. We also tracked the number of expired units of whole blood during the period of data collection. We analyzed our data with descriptive statistical measures. From July 6, 2022 through March 30, 2023, our system transported a total of 1437 trauma activation patients, with 41 (2.9%) receiving WBT. In total, 19 (46.3%) of these patients were transported by helicopter and 22 (53.7%) were transported by ground. The median age was 31 years (IQR: 25-58), and 35 (85.4%) of these patients were male. Of the 41 patients who received WBTs, 14 (34.1%) were pulseless prior to the WBT, and 27 (65.9%) still had vital signs before WBT. Among those who were pulseless prior to WBT, none are still alive compared to 81.4% who are still alive among those not initially in arrest. However, 2 patients who were initially pulseless regained vital signs after WBT. The overall mortality rate so far is 46.3%. No adverse events related to transfusion were identified following WBT administration in our series. The 41 patients who underwent WBT received a total of 43 units of whole blood while 30 units of whole blood reached expiration of the unit’s shelf life prior to transfusion. So far, in our EMS system, WBT has been used on about 2.9% of trauma activation transports, and no adverse events related to transfusion have been identified. Survival rates have been > 80% for those initially with vital signs, but no patients who were initially pulseless have survived to hospital discharge so far. Additional data are needed to determine how to best utilize WBT in the prehospital setting while minimizing unused blood.