Significance of initial hemoglobin levels in severe trauma patients without prehospital fluid administration: a single-center study in Japan

OBJECTIVES: Hemoglobin (Hb) levels have been considered to remain stable in the early stages of bleeding due to trauma. However, several studies have reported that rapid compensatory fluid shifts cause Hb dilution earlier than previously thought. These reports are from Western countries where it is standard protocol to administer fluids during an emergency, making it almost impossible to eliminate the effect of prehospital intravenous fluid administration on Hb levels. This study aimed to determine the relationship between Hb levels and severity of injury on arrival at the hospital in severe trauma patients without prehospital intravenous fluid administration. METHODS: This single-center observational retrospective study included patients with Abbreviated Injury Scale scores of 3 or above between 2008 and 2014. In Japan, prehospital life-saving technicians were not allowed to administer intravenous fluids until 2014. We investigated whether the difference between the measured blood Hb level at arrival and the corresponding standard blood Hb level for each age group and sex reported in the national survey was associated with the severity of injury and the need for hemostasis. RESULTS: In total, 250 patients were included in this study (median age, 46 years; male patients, 183). The median time from injury to arrival at the hospital was 45 min, and there was no statistical correlation with the initial Hb level on arrival (ρ=0.092, p=0.14). When the study subjects were stratified into four groups according to the initial Hb levels, lower Hb levels correlated with higher rates of requirement for hemostatic interventions (p=0.02) and mortality (p=0.02). In addition, lower Hb levels were associated with the need for hemostasis. CONCLUSION: In severe trauma patients without prehospital intravenous fluid administration, decreased Hb levels on arrival may be associated with the severity of trauma and with the need for hemostasis. LEVEL OF EVIDENCE: Level IV.