RESUMO
Background: The pathophysiological hallmark of the hepatorenal syndrome (HRS) is renal vasoconstriction. Doppler ultrasonography can be used to assess the vascular resistance in small renal intraparenchymal vessels through analysis of the Doppler waveform by a parameter termed Resistive Index (RI). We postulated that the RI could be important for the diagnosis and prognosis of HRS. Aims: to assess the RI in cirrhotic patients with ascites, with and without HRS. Patients and methods: We studied 48 cirrhotics with ascites, of whom 12 were with and 36 without HRS and other 23 were normal subjects. We measured the intrarenal arterial RI (Resistive index = Peak systolic velocity - Minimum diastolic velocity/Peak systolic velocity) with color Doppler ultrasonography after visualization of interlobular or arcuate arteries. It was considered abnormal when higher than 0.70. Results: The RI values, mean and SD) were: normal subjects: 0.58 ñ 0.05, cirrhotics with ascites: 0.65 ñ 0.05 and cirrhotics with ascites and HRS: 0.78 ñ 0.11. Patients with HRS had significantly higher values than those without HRS (p < 0.001). The Relative Risk of developing the HRS in patients with a RI ü 0.70 were 3.32 (CI 95 percent = 1.79 - 6.2) Conclusions: The RI was useful in patients with cirrhosis and ascites for the prognosis of HRS and could suggest diagnosis of HRS with values of 0.78 or higher, if other clinical conditions that produce renal vasoconstriction are excluded