[Effects of lactulose treatment on the course of subclinical hepatic encephalopathy].

OBJECTIVE

To observe the natural history of subclinical hepatic encephalopathy (SHE) and to compare the efficacy of long-term and short-term treatment of lactulose.

METHODS

Sixty SHE patients with abnormal psychometric tests performance and/or evoked potentials were randomly divided into 3 groups of 20 cases: control group (given vitamin B complex only for 24 weeks), short-term lactulose group (administered orally with lactulose 15 - 90 ml/d for 8 weeks in addition to vitamin B complex as described above), and long-term lactulose group (administered orally with lactulose 15 - 90 ml/d for 24 weeks in addition to vitamin B complex as described above). Blood ammonia, liver function, number connection test (NCT), digital symbol test (DST), quality of life, and somatosensory evoked potential (SEP) were investigated 0, 8, 16, and 24 weeks after the onset of experiment. The incidence of HE was recorded.

RESULTS

No statistically significant difference was found in terms of liver function score of ENVER, and SEP any time after the onset of the experiment (all P > 0.05). Eight weeks after the onset of experiment the performance of NCT and DST was significantly improved in the 2 lactulose groups than in the control group (both P < 0.05), without significant difference between the two treatment groups (P > 0.05). However, significant difference failed to appear in blood ammonia 8 weeks after, and began to be found since the 16th week between the control group and long-term lactulose group (P < 0.05). Since the 16th week the condition of the long-term lactulose group was much better than those of the other 2 groups in terms of blood ammonia, NCT performance, scores of PHYS, PSYCH, and SCOIL (all P < 0.05), and not in DST performance (P > 0.05). 24 weeks after, the condition of the long-term lactulose group was still better than those of the other 2 groups (all P < 0.05), however, no significant difference was found in terms of the above-mentioned indicators between the control and short-term lactulose groups (all P > 0.05). The HE prevalence of the control, short-term lactulose, and long-term lactulose groups were 40%, 30%, and 5% respectively 24 weeks after, with a significant difference between the long-term lactulose group and between any of the other groups (both P < 0.05) and without a statistically significant difference between the control and short-term lactulose groups (P > 0.05).

CONCLUSION

Long-term lactulose treatment lowers blood ammonia and improves the psychometric performance and quality of life, thus lowering the prevalence of clinical HE. However, short-term lactulose treatment fails to improve of the natural course of HE.