A case of syndrome of inappropriate antidiuretic hormone (SIADH) after the resection of lung cancer

Abstract

A 71-year-old male was found to have an abnormal shadow at a mass survey roentogenogram. The tumor was diagnosed as pulmonary adenocarcinoma and right upper lobectomy was performed. On postoperative day 3, remarkable hyponatremia, low plasma osmolarity, high plasma ADH level and high urinary sodium excretion with disorientation were appeared. He was diagnosed as SIADH. His clinical symptoms were improved by fluid restriction and hypertonic saline infusion. In this case the direct cause of SIADH was not detected, but we speculated he had pathogenesis of SIADH potentially and postoperative intra-pleural inflammation and surgical stress after pulmonary resection influenced the appearance of SIADH.