Hemoglobin drops within minutes of injuries and predicts need for an intervention to stop hemorrhage.

BACKGROUND: Hemoglobin (Hgb) levels obtained shortly after injury may not detect occult bleeding in trauma patients because of the time needed for plasma levels to equilibrate, or may be confounded by crystalloid-related hemodilution. We hypothesized that Hgb levels measured within minutes of arrival can identify trauma patients who are actively bleeding.
METHODS: A retrospective study of 404 consecutive patients was undertaken at an urban Level I trauma center, which included 39 patients who required emergent surgical or radiologic intervention to control bleeding. All 404 patients underwent point-of-care Hgb measurements within 30 minutes of emergency department (ED) arrival. Hgb levels were correlated with physiologic signs of hemorrhage(blood pressure, heart rate, base deficit, pH, and resuscitation volume), and the need for emergent interventions to stop hemorrhage.
RESULTS: Early Hgb levels were significantly lower in patients who required emergent interventions to stop hemorrhage (mean +/- SD: 12 +/- 2 gm/dL vs. 13 +/- 2 gm/dL, p < 0.001). Lower Hgb levels were associated with increasing heart rate, decreasing blood pressure, decreasing pH, worsening base deficit, and increasing transfusion requirements. Hgb < or =10 gm/dL was associated with a greater than three-fold increase in the need for emergent interventions to stop bleeding (odds ratio 3.14, 95% confidence interval 1.18-8.35, p < 0.03), and correctly identified the need for intervention in 87% of patients.
CONCLUSION: Hemorrhage in trauma patients is associated with an early decrease in Hgb level. Hgb < or =10 gm/dL in the first 30 minutes of patient arrival will correctly identify presence or absence of significant bleeding in almost 9 of 10 trauma patients.