Anesthesia and Bartter's syndrome: a case report and review.

A 22-year-old female with Bartter's syndrome presented at 40 weeks' gestation for elective cesarean section under general anesthesia. Her usual medication was ibuprofen and potassium supplements. Preoperative potassium was 3.3 mmol/L, and in anticipation of difficulties in fluid, electrolyte, and acid-base management, a central line and urinary catheter were inserted and blood gases measured. In the first 20 hours postdelivery she had a brisk diuresis and required 3.5 L of crystalloid to maintain her central venous pressure and 100 mmol of potassium to prevent significant hypokalemia. The main features of Bartter's syndrome are growth retardation, hypertrophy, and hyperplasia of the juxtaglomerular apparatus, increased angiotensin II, hyperaldosteronism, hypokalemic alkalosis, normal blood pressure, and decreased response to pressors. The precise biochemical lesion is unknown, but it is most probably an abnormality of chloride transport in the loop of Henle. Anesthetic management is a major challenge, requiring a thorough understanding of the pathophysiology of the syndrome. The specific aims of the anesthetist are to maintain cardiovascular stability, control serum potassium, and prevent renal damage. Perioperative fluid balance must be meticulously managed, and drugs dependent on renal excretion must be used with caution. Metabolic alkalosis may interfere with the binding of drugs. The patient's short stature, platelet abnormalities, and reduced responsiveness to pressors all make regional anesthesia theoretically hazardous.