Renal blood flow in cirrhotic patients and hepatorenal syndrome (HRS)

Aim

To assess the effect of liver cirrhosis and ascites on the renal blood flow.

Methods

A prospective study that includes 40 consecutive patients with liver cirrhosis divided into two groups according to presence of renal dysfunction (group B) or its absence (group A). Another 10 normal volunteers were considered as control (group C). All patients were subjected to clinical, laboratory, ultrasonographic, Duplex study on renal artery and isotopic study for the estimation of total effective renal plasma flow (ERPF). The renal fraction of cardiac output (CO) was also estimated (ERPF/CO). By renal Duplex, the renal vascular resistances were estimated using resistivity index (RI) and pulsitility index (PI).

Results

Mean total ERPF was significantly lower in-group B (HRS) compared to group A (cirrhotics) (330 ± 61 ml/min vs 708 ± 144 ml/min, P = 0.00). The mean (ERPF/CO) was significantly lower in-group B (HRS) than group A (cirrhotics). (4.02 ± 0.53% vs 9.5 ± 1.2%, P = 0.00). Both groups A&B had lower mean total ERPF & ERPF/CO than group C, (862 ± 130 ml/min and 16.5 ± 0.8%, P = 0.00).

Both RI and PI were higher in group B and A than group C (0.73 ± 0.06, 1.3 ± 0.2 in group B, 0.66 ± 0.7, 1.2 ± 0.3 in group A vs 0.59 ± 0.05, 1.00 ± 0.3 in group C, P = 0.00). PI was similar in group A&B, while RI was significantly higher in group B than A, P = 0.03.

Conclusion

Patients with HRS showed marked diminution in total ERPF & ERPF/CO when compared with normal volunteers, while cirrhotics only showed mild diminution in total ERPF & ERPF/CO compared with volunteers. However, renal blood flow when measured by duplex showed similar elevation in the renal vascular resistance in both HRS & cirrhotics.