Early predictive factors on mortality in head injured patients: a retrospective analysis of 112 traumatic brain injured patients

Aim. Early hyperglycemia is a feature of traumatic brain injured (TBI patients. The aim of our study was to analyze the impact of early hyperglycemia on in-ICU mortality in isolated TBI and its correlations with other factors responsible for secondary injury. Methods. We studied admission values (AV) and worse values in the first 48 hours (WV 48 h) of 112 ICU TBI patients (mortality 29.6%) of blood glucose (BG), base excess (BE), mean arterial pressure (MAP), PaO2/FiO(2) ratio and serum hemoglobin (Hb). Predictive strength as the area under the receiver operating curves (AUROC) and correlation between all variables were calculated. Results. Data are expressed as median, 1st-3rd quartile. Both BG AV (147.5, 126-182 mg/dL; AUROC 0.716, P=0.0002) and WV 48 h (156.5, 132-192 mg/dL; AUROC 0.721, P=0.0001) are predictive of mortality. AV and WV 48 h are respectively: PaO2/FiO(2) (366.8, 237.2-477.6 vs. 320,214.4.426; P=0.05), MAP (90,80-100.5 vs. 75,66-83 mmHg; P<0.0001) and Hb (11.4,9.7-13.1 vs. 10.6,9-12.2 g/dL; P<0.02). BG AV and WV 48 h correlates with: age (r=0.419, P<0.0001 and r=0.489, P<0.0001), PaO2/FiO(2) AV (r -0.223, P<0.03 and r -0.236, P<0.02), PaO2/FiO(2) WV 48 h (r -0.215, P<0.03 and r -0.279, P<0.005) and MAP WV 48 h (r -0.216, P<0.03 and r -0.261, P<0.007). Conclusion. Early hyperglycemia is a major predictor of mortality and correlates with other factors responsible for secondary injury. Early hyperglycemia seems to be a marker of inflammatory reaction responsible for early cardiovascular and respiratory impairment.