Hypophosphatemia in Severe Traumatic Brain Injury* Hipofosfatemia no Traumatismo Cranioencefálico Grave

BACKgRoUnD AnD oBJECTIVES: The aim of this study was to identify the incidence of hypophosphatemia in severe traumatic brain injury (TBI), as well as to investigate the causes and its clinical significance. METHoDS: Fifty-nine serum phosphate determination were done in 14 severe TBI in adults RESUlTS: Seven patients developed hypophosphatemia (< 2 mg/dL). Univariate analysis exhibited association of low phosphate levels with higher pH (p = 0.0129), severe systemic inflammatory response syndrome (SIRS) (p = 0.0008) and positive water balance (p = 0.0001). Multivariate analysis highlighted only the association of hypophosphatemia with severe SIRS (p = 0.0001) and lower urine output (p = 0.0126). It was estimated that risk of death increased 3.24 times when serum phosphate fell by one mg/dl. Severity of SIRS was a determinant factor of death (p = 0.005). ConClUSIonS: Hypophosphatemia is common in TBI and it appears to be associated to SIRS. Alkalosis and volume expansion were contributing factors. Hypophosphatemia in TBI is a marker of severity and death.