Shahi V, et al. - Whether or not serial hemoglobin measurement (ΔHgb) is a reliable diagnostic tool in assessing blood loss in blunt trauma patients was determined. Researchers measured 2 hemoglobin levels spaced 5 min apart and calculated the difference (ΔHgb) in all consecutive blunt trauma patients ≥18 years of age who presented to a level I trauma center. Whether each patient required any of the following interventions to treat their injuries was also recorded: 1) operation or procedure to control hemorrhage; 2) radiographic embolization; 3) administration of blood and blood products; 4) administration of ≥3 liters of intravenous fluids; and 5) exsanguination. As per outcomes, ΔHgb was not reliably distinguishing blunt trauma patients who require intervention from those who do not.