Accuracy of estimation of external blood loss by EMS personnel

Background: Emergency Medical Services (EMS) personnel provide care in the out-of-hospital setting. The EMS report, including blood volume estimates, influences hospital management. Our objective was to assess the accuracy of EMS blood volume estimates. Methods: In this prospective, observational study, EMS providers were asked to view four simulated blood loss scenarios in random order. Each scenario used a specific volume of spilled blood corresponding to the loss likely t o cause the four classes of hemorrhagic shock. Estimates are reported using median and interquartile ranges. Results: Ninety-two EMS providers gave 368 estimates, Only 8% were within 2 0% of the actual volume. Furthermore, only 24% were within 50% of actual vo lume, There was no correlation between accuracy and any demographic variabl e, level of training, or years of ER IS experience. Conclusion: EMS personnel are unable to estimate "blood" volume accurately irrespective of level of training.