Objective: To analyse the effectivity of acute phase reactants in intensive care patients with the use of step-wise logistic regression analysis. Design: Retrospective analysis of data of intensive care patients. Material and Methods: Examination of procalcitonin (PCT), C-reactive protein (CRP), orosomucoid, leukocytes and other variables in septic ICU patients or ICU patients with multiorgan failure. 164 examinations in 43 patients were evaluated. The used method was logistic regression analysis with the aim to evaluate the effectivity of laboratory and other markers in relation to clinical condition (Apache II, SOFA, SIRS, MODS, survival rate, apparent infection, bacteriology). Results: PCT was the most frequently selected variable in step-wise method. No significant differences were found for PCT between quantitative method and qualitative POCT method. Less effective were examinations of orosomucoid, fibrinogen, albumin and prealbumin as positive, or negative acute phase reactants. Correct classification with the use of acute phase reactants (CRP, PCT, orosomucoid) and leukocytes was between 58–77%. Classification based on PCT (or CRP) improved when other variables were added (body temperature, INR, leukocytes, platelets) and reached 71–83% of correct classifications. Conclusions: Procalcitonin (quantitative or qualitative) was the analyte with the best discriminant effectivity for clinical conditions in ICU patients (apparent infection, positive bacteriology, survival rate, multiorgan failure and scoring systems Apache II, SIRS and SOFA). However, PCT alone cannot discriminate clinical conditions sufficiently. Classification improves when PCT (or CRP) is evaluated together with other examinations, of which platelets, leukocytes, INR and body temperature are of highest value. On the other hand, less effectivity was found for albumin, prealbumin, orosomucoid and fibrinogen.

        Key words: procalcitonin, acute phase reaction, intensive care, logistic regresssion analysis.