Distinguishing cerebral salt wasting syndrome and syndrome of inappropriate ADH in a patient with traumatic brain injury.

A previously healthy 48-year-old woman was referred to our intensive care unit (ICU) from a neurosurgical ward due to deterioration of her conscious level. She had a road traffic accident 6 days earlier. On admission to the hospital, a brain CT demonstrated subarachnoid haemorrhage which was considered not amenable to surgical intervention. A second CT brain performed shortly after admission to ICU showed no change in comparison to the initial CT. Serum sodium level on ICU admission was 108 mEq/L; serum and urine osmolalities were 223 mOsm/kg and 438 mOsm/kg, respectively. Her hyponatraemia was initially attributed to syndrome of inappropriate antidiuretic hormone. However, a clinical impression of low volume status raised the suspicion of cerebral salt wasting syndrome. She was managed by infusion of hypertonic saline and fluids for 5 days and discharged from ICU after improvement of her conscious level and normalisation of serum sodium.