A Case of Persisting Hyponatremia After Severe Traumatic Brain Injury

BACKGROUND: Hyponatremia is a common and clinically significant complication following traumatic brain injury (TBI), with important implications for neurological stability and functional recovery. Etiologies include syndrome of inappropriate antidiuretic hormone secretion and cerebral salt wasting syndrome. These can present with similar laboratory findings but require different management approaches. Failure to accurately identify the underlying mechanism can lead to ineffective treatment and impeded recovery. METHODS: This is a case study describing an older adult male with severe TBI who developed persistent hyponatremia during inpatient rehabilitation despite standard interventions, including salt supplementation, fluid management, and intravenous fluid therapy. Clinical evaluation, serial laboratory monitoring, and multidisciplinary management guided diagnostic assessment and treatment. RESULTS: The patient demonstrated refractory hyponatremia despite conventional therapy. Following nephrology consultation, treatment with oral urea was initiated, resulting in stabilization and gradual normalization of serum sodium levels without further electrolyte deterioration. CONCLUSION: This case highlights the diagnostic and therapeutic challenges of managing hyponatremia after TBI, particularly in the rehabilitation setting where neurological recovery and electrolyte disturbances may overlap. It underscores the importance of individualized treatment strategies and close monitoring of serum sodium trends. Neuroscience nurses play a critical role in early recognition, ongoing assessment, and timely intervention to prevent complications and support optimal patient outcomes.