CALCA and infection: PCT levels increased in all groups, peaked at 24 hours, remained high in patients with systemic infection, and normalised in others.CRP levels increased, peaked at 24 to 48 hours, and remained high in all groups; systemic infection > local infection > control group.PCT levels correlated with CRP levels only in infected patients.PCT: cut-off 4 ng/ml, sensitivity 86%, specificity 98% in predicting infection.CRP: cut-off 180 mg/l, sensitivity 100%, specificity 75% in predicting infection.