2016 年 31 巻 2 号 p. 406-411
An 80-year-old elderly woman with ovarian fibroma underwent single incision laparoscopic salpingo oophorectomy. On postoperative day 4, she complained of headache and dizziness, and she gradually developed disturbance in consciousness such as hallucinations and disorientation. Laboratory findings revealed severe low serum sodium concentration at 107 mEq/l, plasma osmolality at 219 mOsm/l, and a high urine sodium concentration at 72 mEq/l. Anti-diuretic hormone ( ADH ) level was elevated ( 4.6 pg/ml ) despite low plasma osmolality. Although severe intravascular dehydration findings such as tachycardia and hypotension were not observed, computed tomography imaging showed a flattened inferior vena cava, suggesting decreased extracellular volume. The pathogenesis underlying the hypotonic hyponatremia was diagnosed as mineralocorticoid responsive hyponatremia of the elderly, which is a subset of renal salt wasting syndrome, rather than a syndrome of inappropriate secretion of antidiuretic hormone. She was treated with fludrocortisone ( 0.1 mg/day ), following hypertonic and isotonic infusion.
In elderly patients, postoperative complications, including electrolytes disturbance, may occur frequently, because of their reduced anti-stress capability. Careful postoperative management is required even in those patients who underdo minimally invasive endoscopic surgery.
