Death from Acute Hyponatremia Following Uneventful Abdominal Hysterectomy: Lessons from a Case Report

A 38-year-old woman underwent a routine/uneventful abdominal hysterectomy for abnormal uterine bleeding (AUB) and uterine fibroids. Approximately 24 hours later, she developed severe hyponatremia (Na = 118 mEq/L), brain edema and coma, and she died 3 days later. The mechanism of hyponatremia was, likely, due to excessive and/or inappropriate fluid infusion of 2/3:1/3 solution. The inability to regulate her fluids and electrolytes (Na and K), was, likely, related to addback estrogen therapy given for 3 months preoperatively in conjunction with a GnRH agonist to optimize the patient’s hemoglobin and shrink the uterus/fibroids. It has been known that postmenopausal women and men can regulate excessive hyponatremic fluid absorption and electrolytes better than premenopausal women implicating an estrogen role. Estrogen has been found to inhibit the Na/K-ATPase pump in a variety of tissues/organs including the brain. This woman’s pathology of the endometrium was reported as proliferative indicating that enough estrogen may have been available to inhibit her Na/K-ATPase pump resulting in inability to regulate her fluids and electrolytes leading to her death.