Monitoring of transtubular potassium gradient in the diuretic management of patients with cirrhosis and ascites

Background/Aims: Aldosterone antagonists are the diuretics of first choice in the treatment of cirrhotic ascites. However, there is still no reliable clinical parameter to evaluate their efficacy. Transtubular potassium gradient (TTKG), the accurate indicator of aldosterone bioactivity, may serve as a guide for the proper use of the aldosterone antagonists. Methods: In 23 patients with cirrhotic ascites, the daily administered initial dosage of 100 mg of spironolactone was increased by 100 mg/day at intervals of 5 days until either diuresis commenced or TTKG fell below 3.0, the value indicating complete blockade of aldosterone bioactivity. For the non-responders with TTKG lower than 3.0, furosemide was given in addition to spironolactone.Results: Basal TTKG correlated significantly with plasma aldosterone concentration (r = 0.60, P = 0.002). Spironolactone induced the decrease of TTKG in 20 patients, from 5.3 +/- 0.5 to 2.9 +/- 0.2 (mean +/- SE, P < 0.001). A TTKG value of 3.0 could classify seven patients, who did not respond to low dose spironolactone, into two distinct groups at that time, indicating different further diuretic regimen. All patients achieved diuretic responses without complication by this TTKG-guided modification of diuretics. Conclusions: TTKG may be a suitable guide for the diuretic management of cirrhotic ascites by accurately reflecting the effect of aldosterone antagonists.