SIGNIFICANT HYPOPHOSPHATEMIA IS PREDICTIVE OF BRAIN DEATH IN SEVERE TRAUMATIC BRAIN INJURY

Objectives: Traumatic brain injury (TBI) is associated with multiple severe metabolic derangements. Clinically, hypophosphatemia (HP) can interfere with the neuromuscular exam and clinical brain death testing. The incidence and prognostic relationship of HP to severe TBI are poorly described. We hypothesize that the degree of HP in TBI is an indicator for progression to brain death.

Methods: Retrospective analysis was completed for all patients, between 16 and 89 years of age from 1/1/2016 to 12/31/2021 admitted to the shock trauma ICU with a severe TBI as defined as initial GCS of 8 or less. Baseline demographics, laboratory studies, hemodynamic parameters, vasopressor use, transfusion volumes and brain death (BD) were collected and analyzed. Univariate and multivariate analysis was undertaken.

Results: 384 patients were identified with a severe TBI, 8 were excluded from analysis. Univariate analysis demonstrated a HP was correlated with BD (p < 0.0002). Further multivariate analysis showed that HP to BD was the only correlation with a p value < 0.0001. No additional physiologic or metabolic derangements demonstrated any significance.

Conclusion: While correction of electrolytes is required for determination of brain death, this may prove to be an unnecessary task as severe HP is predictive of progression to brain death exclusive of additional metabolic derangements. The prognostic value of HP in TBI warrants further study.