Hyponatremia and SIADH: A Case Study for Nursing Consideration

Hyponatremia is an electrolyte abnormality commonly encountered in oncology practice and is usually defined by a serum sodium level less than 135 meq/L (Castillo, Vincent, & Justice, 2012). Syndrome of inappropriate antidiuretic hormone (SIADH) is the leading cause of hyponatremia in patients with cancer, occurring in as many as 30% of all cases (Raftopoulos, 2007). The cardinal symptoms of SIADH are presented in Table 1. The crucial signs of SIADH are hyponatremia, serum hypo-osmolality,and less than maximally diluted urine.