Objective:To improve the diagnosis and therapeutic effect of occurrence and development of hyponatremia and disorder of acid-base balance among patients with hepatic encephalopathy（HE） by elucidating the regularity and mechanism

as well as its influence on prognosis.Methods:327 HE patients admitted to our hospital from January 1990 to June 2010 were enrolled.Meanwhile 316 patients hospitalized in the medical department of the same hospital were chosen as the control group.Patients in both groups were given the same methods to measure arterial blood gas parameters（pH value

PaCO2

[HCO3-]

TCO2

BE and SaO2）

blood biochemistry（[Na+]

[K+]

[Cl-]）

liver function

kidney function and blood glucose

serum sodium

and thereupon tocalculate the anion gap（AG） and the potential [HCO3-]

and acid-base balance disorder.Results:Among the 327 HE patients

hyponatremia was found in 188 cases（57.4%）

of whom 132 patients died（70.2%）.While among the 316 patients in control group

68 presented with hyponatremia（21.5%）

and 19 died（27.9%）.The incidence and mortality were significantly different between the two groups（P<0.001）.All the 327 patients presented with different degrees of acid-base balance disorder and 178 died（54.4%）

in whom 164（50.2%） belonged to simple acid-base balance disorder and 74（45.1%） died

136（41.6%） were dual acid-base balance disorder and 80（58.8%） died

27（8.2%） were triple acid-base disturbance and 24（88.9%） died.Whereas in the control group only 83 patients（26.2%） were recognized as simple and dual acid-base balance disorder

and 18（21.7%） died.There was higher incidence of acid-base balance disorder and mortality rate in HE group than control one（P<0.001）.Conclusion:Hyponatremia is valuable to judge HE patients’ prognosis.The key parameters in the judgment and evaluation on acid-base balance disorder among HE patients are the change of pH values and serum electrolyte values.When pH value ≤ 7.30 or > 7.55

it generally suggests a poor prognosis.