[Immunologic changes and infection in severely injured patients]

The severity of major surgery determines the extent of immunodeficiency which follows. The most pronounced immunodepression is found after severe blunt trauma; in polytraumatized patients the alterations of many measured parameters correlate with the injury severity score (ISS) i.e. with the severity of the injuries. Infection is also followed by many changes in the immune response. A score including serum concentrations of IgA, beta 2-microglobulin and percentage of monocytes was found to be predictive for the first 3 days after trauma with regard to subsequent occurrence of infection. In the first post-trauma day the lymphocyte-monocyte ratio correlates with the probability of survival or death by infection. Pneumonia occurred in 47% and septicemia in 22% of 150 polytraumatized patients ventilated artificially for more than 24 hours. The first signs of these infections were already present during the first 5 days, i.e. in the period of the most severe immunodeficiency. The preliminary results of a pilot study with immunomodulation by thymopentin are encouraging and show a significant decrease in the frequency of infections.