Anesthetic management of a patient with Bartter's syndrome.

Bartter's syndrome is a rare disorder characterized by normal or low arterial blood pressure (BP), despite marked elevation in plasma renin activity, angiotensin II (Ang-II), and aldosterone, along with hypokalemic metabolic alkalosis. Perioperative changes in the cardiovascular and renin-angiotensin-aldosterone (RAA) systems in Bartter's syndrome patients are not well understood. We managed a 44-year-old Japanese man with rectal cancer and Bartter's syndrome complicated by renal dysfunction. He underwent anterior resection of the rectum with general anesthesia (50% nitrous oxide-oxygen with 0.5% to 0.8% isoflurane, supplemented with intravenous midazolam and butorphanol). Epidural morphine was given postoperatively. Although BP tended to be lower (75/35 to 110/60 mmHg) during surgery, there were no profound perioperative hemodynamic derangements. Plasma renin activity. Ang-II, and aldosterone values were highest during surgery. These responses of the RAA system to anesthesia and surgery were the same as previously noted in otherwise healthy surgical patients.