Systemic inflammation and bacterial infections are critical occurrences after pediatric cardiac surgery. Elevated white blood cell count and C-reactive protein cannot discriminate between these two conditions in the early postoperative period. The aim of this study was to understand whether procalcitonin (PCT) values within 48 hours of surgery could be a useful marker of postoperative infection.

Retrospective observational study.

The study was performed in a teaching hospital.

All patients ≤six years of age.

Cardiac surgery on cardiopulmonary bypass from January 1, 2017 to January 1, 2020.

PCT, white blood cell count, and C-reactive protein values were measured at intensive care unit admission and at 24 and 48 hours after surgery. All positive cultures in the first seven days after surgery were recorded. Out of 177 consecutive patients, 22 (12%) developed infections. PCT at 48 hours after surgery was the only laboratory predictor of infections in the first seven days after surgery (p = 0.02). Receiver operating curve analyses on PCT values at 48 hours identified an optimal cut-off value of 1.85 ng/mL in the overall population. Area under the curve was 0.63, sensitivity 63%, and specificity 69%.

In light of this preliminary result, the clinical relevance and predictive accuracy of PCT are promising in patients with increasing values of PCT but need to be confirmed in a larger sample.