# Combining procalcitonin, c-reactive protein, and white blood cell count in predicting infections in pediatric open cardiac surgery with cardiopulmonary bypass

## TL;DR

This study shows that combining procalcitonin with other biomarkers improves early infection prediction after pediatric heart surgery.

## Contribution

The study introduces a combined biomarker model for early infection detection in pediatric cardiac surgery patients.

## Key findings

- PCT alone on postoperative day 3 had limited predictive value (AUC 0.67).
- Combining PCT with CRP and WBC improved infection prediction (AUC 0.81).
- The combined model showed a 9.66 times higher hazard ratio for infection prediction.

## Abstract

This study aimed to evaluate the validity of models using Procalcitonin (PCT) alone and PCT combined with other biomarkers to predict early infection after pediatric open-heart surgery with cardiopulmonary bypass (CPB).

A prospective observational study was conducted on children undergoing open-heart surgery with CPB, without preoperative infection. Procalcitonin, C-reactive protein (CRP), and white blood cell (WBC) count were measured preoperatively and on postoperative days 1 and 3. Postoperative infection was defined according to the Centers for Disease Control and Prevention 2008 criteria.

Fifty eligible cases were included, comprising 46 % males with a median age of 7 months (4–17). The AUC (area under the curve) for PCT on postoperative day 3 was 0.67 (0.51–0.82) (p = 0.085). The AUCs for the models combining PCT + CRP and PCT + WBC were 0.71 (0.57–0.86) (p = 0.014) and 0.72 (0.55–0.86) (p = 0.014), respectively. The AUC for the model combining PCT + CRP + WBC was 0.81 (0.69–0.93) (p = 0.002). The combination of PCT > 4.15 ng/ml, CRP > 22.03 mg/l, and WBC > 15.3 × 103/µl predicted infection with a hazard ratio 9.66 times (2.94–31.72) higher than PCT > 4.15 ng/ml alone (p < 0.05).

PCT measurement on the third postoperative day alone cannot predict infection in pediatric open-heart surgery with CPB. The combination of PCT with CRP and WBC may enhance early infection prediction, although further validation in larger, multicenter cohorts is warranted.