Severe Hyponatremia in a Septic Patient With Bronchopneumonia: A Case Report

Hyponatremia is a common electrolyte abnormality encountered in hospitalized patients and may arise from a variety of etiologies, including infection, medications, endocrine disorders, and inappropriate fluid management. Severe hyponatremia can lead to significant neurological morbidity and requires careful evaluation and management. We report the case of a 72-year-old woman with a background of chronic obstructive pulmonary disease (COPD) and type 2 respiratory failure who developed persistent severe hyponatremia during treatment for sepsis secondary to bronchopneumonia. Despite treatment with broad-spectrum antibiotics and fluid restriction, the patient's sodium remained low at approximately 116 mmol/L. Extensive investigations, including serum osmolality and serum cortisol, were within normal limits. Following the escalation of antibiotic therapy from aztreonam to meropenem and the removal of the fluid restriction, the patient's sodium levels gradually improved over several days. This case highlights the importance of reassessing fluid management and ongoing sepsis as contributing factors in persistent hyponatremia.