Comparative study of spot urine Na/K ratio and 24-hour urine sodium in natriuresis evaluation of cirrhotic patients with ascites

AbstractIntroductionThe “spot” urine sodium/potassium (Na/Ku) ratio is a convenient tool to identify sodium excretion<78mequiv./d. It has been established that this ratio is as useful and accurate as 24-h urine sodium (Nau24h), but no Latin American study has evaluated this issue. The aim of this study is to evaluate the accuracy of the Na/Ku ratio and to compare it to Nau24h.Materials and methodsThis cross-sectional study included 20 patients with decompensated liver cirrhosis and ascites.ResultsMean age was 56.1±11.8 years old, 70% were men and 60% presented Nau24h<78mequiv./d. Poor sodium excretion group presented higher MELD score (P=0.002), creatinine (P=0.029), AST (P=0.027) and bilirubin (P=0.013) levels, and also lower median spot sodium urine (P=0.001). There was a high positive correlation between Na/Ku ratio and Nau24h (r=0.857; P<0.001) and negative correlation with MELD (r=−0.498; P=0.025) and serum creatinine (r=−0.498; P=0.025). The AUROC of Na/Ku in predicting Nau24h