Endocrine Abstracts

Hyponatremia is the most common disorder of electrolytes encountered in clinical practice, occurring in 15-30% of acutely or chronically hospitalized patients. Although many cases are mild and relatively asymptomatic, hyponatremia is nonetheless important clinically because: acute severe hyponatremia can cause substantial morbidity and mortality; overly rapid correction of chronic hyponatremia can cause severe neurological deficits and death. We present Clinical cases of endocrine hyponatremia due to different etiologies.

Case I: 48 y/o male was hospitalized in our clinic due to increased blood pressure, agitation and anxiety. Shortly after admission patient developed tonic-clonic seizure with suppression of cognition, bradypnea and was intubated. Lab work revealed very low sodium levels (Na-109 mmol/l). Patient’s medical history reveals history of clinical depression, which was treated with SSRI. In 12.2022 he was consulted by an endocrinologist due to complaints of polyuria and polydipsia. Based on findings, patient was misdiagnosed with ADH deficiency syndrome (central DI) and was prescribed intranasal desmopressin. Preadmission clinical manifestations (polydipsia, polyuria) and laboratory findings (hyponatremia, low serum osmolality) correspond more with the diagnosis of primary polydipsia. Based on patient’s objective findings, diagnosis was re-evaluated and proper medical treatment was initiated which led to improved outcome.

Case II: 73 y/o female with multiple hospitalizations due to hyponatremia was admitted to our clinic due to complaints of weakness, confusion, nausea. Lab findings revealed hyponatremia, which was associated with quetiapine fumarate, prescribed by her psychiatrist, but switching her medication did not improve her sodium levels. Hyponatremia due to hypervolemia (CHF), SIADH induced by quetiapine fumarate were excluded. Further laboratory testing revealed secondary adrenal insufficiency. Head MRI showed pituitary microadenoma. Patient was prescribed hydrocortisone which markedly improved her overall condition with no further episodes of hyponatremia.

Case III: 57 y/o female with a history of somatotroph adenoma was treated with transsphenoidal surgery. Few days after the surgery patient developed nausea, weakness and confusion. Lab assessment revealed hyponatremia. Diagnosis of SIADH was made and patient was instructed to restrict water consumption. In conclusion, the initial diagnostic approach to the adult patient with hyponatremia consists of a directed history and physical examination as well as selected laboratory tests. Some elements of the history, findings of physical exam, laboratory tests are usually already available, and guide the subsequent diagnostic approach.

References: 1. Diagnosis, evaluation and treatment of hyponatremia: Expert Panel Recommendations – The American Journal of Medicine (2013). 2. https://www.uptodate.com/contents/overview-of-the-treatment-of-hyponatremia