Diagnostic usefulness of the random urine Na/K ratio in predicting therapeutic response for diuretics in cirrhotic patients with ascites

Background: Ascites is a major complication of liver cirrhosis that carries a poor prognosis. Diuretics are used in treatment of ascites in addition to salt restriction. Monitoring of diuretic response can be achieved by measurement of 24-h urinary sodium. Aim of the study: The aim of the study was to evaluate the accuracy of using spot urinary sodium/potassium ratio as an alternative to 24-h urinary sodium in assessment of dietary sodium compliance in patients with liver cirrhosis receiving diuretics. Patients and methods: Sixty patients presenting with liver cirrhosis and ascites were admitted at Cairo University Hospital. All the patients were subjected to full history taking, clinical examination, laboratory investigations including liver function tests, renal function tests, 24-h urine sample (for measuring of sodium) and spot urine sample (for sodium and potassium). The studied patients were divided into two groups: diuretic resistant group (those with 24-h urinary sodium 78 mEq) and diuretic sensitive group (with 24-h urinary sodium 78 mEq). The patients in diuretic resistant group were 18 patients (30%) and those in diuretic sensitive group were 42 patients (70%). Results: Spot urine Na/K ratio was significantly lower in patients in the diuretic resistant group (2.4 ± 2.2) than in the sensitive group (4.7 ± 2.3) (P 0.05). The cutoff point of Na/K ratio that showed highest accuracy was 3.0. Conclusion: This study revealed highly significant correlation between 24-h urinary sodium and spot urine sodium/potassium ratio with sensitivity 75% and specifi city 91.67% at cutoff point of 3.