CALCA and infection: The median PCT values in the severe sepsis and septic shock categories (3.46 ng/mL and 589 ng/mL, respectively), were both well above the 1.62 ng/mL calculated cut-off and 2.0 ng/mL literature cut-off for severe sepsis [10], but these were not significantly different from the median PCT values in non-SIRS and SIRS patients without documented infection.