Retrospective study of continuous haemofiltration on patients with acute liver failure with renal dysfunction

Introduction

Continuous venovenous haemofiltration (CVVHF) is commonly instituted in patients with renal dysfunction in acute liver failure (ALF), the latter carrying a high mortality rate unless patients undergo liver transplantation. In this cohort, the prognostic significance varying doses of CVVHF has not been established. A retrospective analysis of 73 patients admitted to a specialist Liver Intensive Care Unit.

Methods

All patients admitted with acute liver failure and receiving continuous haemofiltration were studied. We analysed data that had been acquired between January 1999 to November 2002 utilising the Riyadh ICU programme. The variables analysed were bilirubin, lactate, creatinine, APACHE II score, noradrenaline, and mechanical ventilation. Patients were divided into three groups. Group 1, low volume (LV) CVVHF (< 2 l exchange); Group 2, high volume (HV) CVVHF (> 2 l exchange); and Group 3, combination of HV and LV CVVHF. These three groups were subdivided as to whether they were receiving noradrenaline, mechanical ventilation or a combination of both.

Results

The survival rate of patients receiving LV or HV CVVHF or a combination was 50%. The subgroup survival is presented in Table 1.

Table 1

Patients receiving LV CVVHF, on noradrenaline, had significantly higher APACHE II (P < 0.03) and creatinine (P < 0.003) levels when compared with those not on noradrenaline. Ventilated patients, on LV CVVHF, had a significantly higher APACHE II score than those not ventilated (P < 0.001). Twenty-eight per cent of patients with ALF underwent transplantation.

Conclusion

This study shows a more favourable outcome when compared with similar patients in a general ICU setting. As expected, patients on HV CVVHF had higher mortality, which is attributable to their underlying physiology. These patients were selected for HV CVVHF at the physician's discretion. The timing of initiation of HV CVVHF did not affect the outcome of these patients. This may be related to the fact that standard CVVHF was initiated early in the time course of the disease.