A patient following head injury was admitted in intensive care ward with signs of raised intracranial pressure. He was put on ventilator and started on intravenous fluids and diuretics. Twenty four hours later his urine output was 3.5 litres, serum sodium 156 mEq/1 and urine osmolality of 316 mOsm/kg. The most likely diagnosis based on these parameters is
|A||High output due to diuretics|
|C||Too much infusion of normal saline|
|D||Cerebral salt wasting syndrome|
High output due to diuretics
1). In this case urine osmolality is high (>300) so option B is rule out.
2). Cerebral salt-wasting syndrome (CSWS) is a rare endocrine condition featuring hyponatremia and dehydration in response to trauma/injury or the presence of tumors in or surrounding the brain.
3). This form of hyponatremia is due to excessive renal sodium excretion resulting from a centrally mediated process.
4). As in this case serum sodium is 156 so CSWS is ruled out.
5). Too much normal saline infusion will not cause hypernatremia.
6). In high output of urine due to diuretics can cause hypernatremia, increase urine osmolality so option A is the best Answer.