Wilson BR, Bruno J, Duckwitz M, et al. - Given the correlation of below normal end-tidal carbon dioxide measurement (ETCO2) with worse outcomes in sepsis and trauma patients as compared with patients with normal ETCO2, researchers here examined the possible utility of ETCO2 in the prehospital setting for predicting transfusion requirement, operative hemorrhage control, or mortality in the first 24 h after admission for trauma. They conducted a retrospective cohort study of patients who were sequentially identified as prehospital trauma alerts from a single EMS system which requires, per policy, ETCO2 for all traumas. They collected 1 year of prehospital data and paired these with hospital trauma registry data. Patients who required transfusion, operative blood loss control, or who died, were compared with those who did not with respect to their ETCO2 values. Among 235 trauma patients transported via the study EMS system, 105 (44.7%) had documented ETCO2 values. Analysis revealed correlation of below normal ETCO2 values with increase necessity for transfusion, operative intervention, and death. For the studied population, optimal cutoff was EtCO2 ≤ 27 with a sensitivity of 72.7% and specificity of 72.2%.