Hypophosphatemia following severe traumatic brain injury is associated with increased risk of mortality

Abstract

Background: Electrolyte dysfunctions following traumatic brain injury have been associated with poor outcomes. The aim of this study was to  determine the incidence of serum phosphate ion abnormalities and their association with specific clinical, radiological and acid-based parameters.
Methods: This was a prospective cross-sectional study of 95 patients with severe head injury hospital admitted between November 2019 and  February 2020. Data collected included patient demographics, injury mechanisms, pre-hospital interventions, clinical examination findings, CT Scan head findings, serum electrolyte findings (at admission and 48 hours later), arterial blood gas, and outcome (30 days). The data collected was entered in the Social Sciences Statistical Package for analysis.
Results: Hypophosphatemia was reported in 40 (42.1%) and 29 (48.3%) of cases, while hyperphosphatemia was reported in 5 (5.3%) and 5 (8.3%) of
cases at admission and 48 hours post-admission. Low phosphate levels were significantly correlated with pre-hospital use of intravenous fluids
(P=0.041), mannitol use (p=0.048), lower diastolic pressure (p=0.043), tachypnoea (p=0.044), hypoxemia (p=0.011) and respiratory alkalosis
(p<0.001). Hypophosphatemia was associated with a high risk of death; odds ratio 4.12(P=0.031) at admission and odds ratio 7.5 (P=0.098) 48hrs postadmission.
Conclusion: Hypophosphatemia is the predominant serum phosphate ion abnormality seen in severe traumatic brain injury and is associated with
significant high risk of mortality.