[Case of severe hypokalemia during emergency surgery caused by long-term administration of Shakuyaku-kanzo-to].

An 82-year-old female underwent emergency surgery for right femoral incarcerated hernia under general anesthesia. Anesthesia was induced and maintained with remifentanil and propofol. Her laboratory data showed severe hypokalemia (1.83 mEq x l(-1)) and metabolic alkalosis (HCO3 36.9 mmol x l(-1)). We suspected that the causes of such abnormalities were due to an endocrinological abnormality, but we could not ascertain the actual cause. Drip infusion of sodium chloride and saline solution infusion, to avoid supplying lactate or acetate, the source of bicarbonate ions, were chosen for palliative treatment. No adverse event occurred during surgery. After surgery, endocrinological functions were examined. Primary aldosteronism was ruled out because serum aldosterone and rennin activity were within normal ranges. The patient had been taking a Kampo preparation, Shakuyaku-kanzo-to, for two years. Glycyrrhizin, the main component of Shakuyaku-kanzo-to, has been reported to be a cause of pseudoaldosteronism by inhibiting the enzyme converting cortisol to cortisone. With these findings we confirmed that severe hypokalemia was induced by pseudoaldosteronism by long-term administration of Shakuyaku-kanzo-to.