Renal Functional Reserve is Well Maintained in Patients with Advanced Liver Cirrhosis and Ascites

Abstract

Background: Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) in healthy humans can be induced by amino acid stimulation. The rise in GFR from baseline to maximum is referred to as the renal functional reserve (RFR). Recently, we showed that the RFR is preserved in patients with compensated cirrhosis despite impaired renal function. In the present study, we evaluated RFR in decompensated cirrhotics with ascites. Methods: Steady-state inulin- and para-aminohippurate (PAH) clearances were performed at rest and during amino acid infusion in 22 patients with decompensated liver cirrhosis and ascites. Results: Baseline GFR and ERPF (means +95% confidence intervals) were: GFR 25.2 (21.1-29.2) ml min -1, ERPF 266.6 (229.7-303.5). Amino acid infusion significantly increased GFR by 67% (38.3-95.8) to 34.6 (29.2-40.0) ml min -1 (means + (95% confidence intervals), P < 0.001) and ERPF by 29% (11.9-46.3) to 326.3 (274.1-378.5) ml min -1 ( P = 0.002). Renal vascular resistance dropped by 13.4% (3.3-23.5) from 29.4 (24.8-33.9) mmHg ml -1 min -1 to 26.4 (22.0-30.7) mmHg ml -1 min -1 ( P = 0.036). The improved kidney function was accompanied by a decrease in systemic aldosterone levels ( P < 0.05). Conclusion: In patients with liver cirrhosis and ascites, amino acid infusion improves kidney function. Trials are warranted to test the long-term effects of amino acid infusions in patients with hepatorenal syndrome.