Multivariate analysis of plasma enzyme profiles in severe head injury.

We followed the changes in the activities of four enzymes (aldolase, aspartate aminotransferase, creatine kinase, and lactate dehydrogenase) in plasma for four days after head injury. The progression of the changes differs significantly between survivors and nonsurvivors. Stepwise discriminant analysis, involving the four enzymes, allowed us to divide 81 to 92% of head-injured patients (n = 280 selected without conscious bias) correctly into the two groups as early as 72 h after trauma. Most of the patients who were misclassified according to our biochemical criteria had received phenobarbital for sedation. Valuable prognostic information in head injury evaluation may thus be obtained by daily determination of enzymatic activities of these four enzymes.