The renal resistive index is a non-invasive indicator of hepatorenal syndrome in cirrhotics

Hepatorenal syndrome (HRS) is defined as unexplained kidney failure in a patient with liver disease. The poor prognosis is due to both liver and renal failure, the latter being due to intrarenal vasoconstriction. The intrarenal arterial Doppler is a noninvasive tool used to study the extent of this vasoconstriction. Aim: To determine if the intrarenal Doppler helps in indicating HRS in established cases of liver cirrhosis. Materials and Methods: A total of 30 cirrhotics aged above 18 years with no prior or co-existing renal disorders were subjected to liver function tests, renal function test, complete blood count, urine examination, viral markers, ultrasonography abdomen, and the intrarenal artery Doppler for the resistive index (RI) calculation. RI was calculated using the formula: RI = (peak systolic flow − peak diastolic flow)/peak systolic flow and RI ≥0.77 was taken as diagnostic of HRS. Results: Out of the 18 patients whose RI <0.77, 17 had normal creatinine. 12 patients who had raised RI, 6 had raised creatinine (2.68), while the other 6 had normal creatinine (0.88) implying that renal RI (RRI) is an early indicator of HRS even before creatinine could rise to fulfill the criteria for HRS. Conclusion: RRI is a useful tool for indicating HRS in cirrhosis of the liver.