Clinical role of low hemoglobin ratio in poor neurologic outcomes in infants with traumatic intracranial hemorrhage

Traumatic brain injury (TBI) is the leading cause of pediatric morbidity and mortality worldwide, and half of all fatalities occur in infants aged less than 1 year. We analyzed 129 infants diagnosed with TBI complicated with intracranial hemorrhage confirmed by brain computed tomography. We defined delta hemoglobin (ΔHB) as nadir HB - age specific mean HB, and the ratio of HB (%) as ΔHB/age specific mean HB x 100. Infants with poor neurologic outcomes had a lower admission HB and ΔHB (p < 0.05). The in-hospital mortality rate was 10.1% (13 infants), and the infants who died had a significantly lower ΔHB ratio compared to the survivors. The area under the receiving operating characteristic curve (AUC) of initial Glasgow Coma Score (GCS) in predicting neurologic outcomes was higher than that of ratio of ΔHB (0.881 v.s 0.859). In multivariate logistic regression analysis with the optimal cutoff ratio of ΔHB, it remained an independent predictor for in-hospital mortality and poor neurologic outcomes at discharge and at 6 months. AUC analysis for the ratio of ΔHB for poor neurologic outcomes in infants aged from 0–6 months was 0.85 and the optimal cutoff was −30.7% (sensitivity, 69%; specificity, 92%; positive likelihood ratio (LR⁺), 8.24; negative likelihood ratio (LR⁻), 0.34); the AUC was 0.88 in infants aged from 6–12 months and the optimal cutoff was −20.6% (sensitivity, 89%; specificity, 79%; LR⁺, 4.13; LR⁻, 0.15).