Background: The purpose of the current study was to investigate the effect of early adrenergic hyperactivity as manifested by prehospital (emergency medical service [EMS]) hypertension on outcomes of traumatic brain injury (TBI) patients and to develop a prognostic model of the presence of TBI based on EMS and admission (emergency department [ED]) hypertension.
Methods: This study is a retrospective review of the 2007 to 2008 National Trauma Data Bank including blunt trauma patients 15 years or older with available EMS and ED vital signs. Patients with head Abbreviated Injury Scale (AIS) score of 3 or greater were selected, and mortality was examined within EMS systolic blood pressure (SBP) groups: lower than 100 mm Hg, 110 mm Hg to 150 mm Hg, 160 mm Hg to 180 mm Hg, and 190 mm Hg to 230 mm Hg. A forward logistic regression model including the EMS heart rate, EMS SBP, EMS Glasgow Coma Scale (GCS) score, ED heart rate, and ED SBP was used to identify predictors of a TBI in patients with ED GCS score of less than or equal to 8, 9 to 13, and 14 to 15.
Results: For the 5-year study period, 315,242 patients met inclusion criteria. Adjusted odds for mortality increased in a stepwise fashion with increasing EMS SBP compared with patients with normal EMS SBP (adjusted odds ratio [95% confidence interval], 1.33 [1.22-1.44], p < 0.001, for EMS SBP of 160-180 mm Hg and 1.97 [1.76-2.21], p < 0.001, for EMS SBP of 190-230 mm Hg). A 7-point scoring system was developed for each ED GCS score group to predict the presence of a TBI. EMS SBP of greater than 150 mm Hg and ED SBP of greater than 150 mm Hg were both predictive of the presence of a TBI in patients with ED GCS score of 8 or less and in patients with ED GCS score of 9 to 13 or 14 to 15, respectively.
Conclusion: Prehospital hypertension in TBI is associated with a higher mortality risk. Early hypertension in the prehospital setting and at admission can be used to predict the presence of such injuries. These findings may have important early triage and treatment implications.
Level of evidence: Prognostic study, level III.