[An experimental study of the mechanism of shock-induced enterogenic infection after long-term standard total parenteral nutrition].

In this study, gnotobiotic rats were subjected to total parenteral nutrition (TPN) and subsequent hemorrhagic shock to study the mechanism of enterogenic infection in these circumstances. (1) Long-term (8-12 days) TPN induced impairment of gut barrier function, evidenced by atrophy of intestinal mucosa, significant decrease in diamine oxidase activity of intestinal mucosa and blood, and marked micro-ecologic imbalance of the intestinal mucosa flora with dominant growth of aerobes and relative decrease in anaerobes. The degree of mucosal damage were proportional to the duration of TPN. (2) In TPN+shock groups, further damage was found in the mucosa, with a large number of invading gram-negative organisms and a significant decrease in DAO activity as compared to that with TPN only groups. These changes were significantly correlated with enhanced bacterial translocation, elevation of LPS and MDA levels in the plasma. These findings suggested that long term TPN impairing gut barrier function, precipitated posttraumatic gut barrier failure. The determination of plasma DAO activity may help in the early diagnosis of gut injury during TPN and after trauma.