Abstract: This study analysed complications and death cuases of 56 cases of fatal epidemic encephalitis B treated with artificial respirator. Average age was 19 years.50/56(89%)cases had complications . 48/56(85.7%)cases hadhospital infection.29 cases had bacillus aeruginosus infection. 8 cases had bacillus mucosus capsulatus infection.3 cases had fungus infection. One cases had bacillus coli infection.7 cases had other G⁺ bacteria infection.During the ten days treated with mechanical ventinator 4/56(7.14%)cases had hospital infection. With the days of mechanical ventinator increased there were 48/56(85.7%)cases who had hospital infection. During 20 days with mechanical ventinator 2/56(3.6 %)cases had bacillus aeruginosus infection. After 20 days with mechanical ventinator 27/56(48.2 %)cases had bacillus aeruginosus infection(P< 0.01). 5 cases had pressure injure. 2 cases had hypodermal emphysema. 3 cases had mediastinum emphysema. 20 cases had hemorrhage of degestive tract. Conclusion :The duration of mechanical ventinator was the key to hospital infection. To decrease the time of mechanical ventinator may decrease infection and fatality rate.

Key words: epidemic encephalitis B, respiratoryfailure, mechanical ventinator, complications