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

Abstract

Objective: 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).

Methods: 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.

Results: 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).

Conclusions: 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.

Keywords: Cardiopulmonary bypass; Open-heart surgery; Pediatric; Postoperative infections; Procalcitonin.

Figure 1

Charts comparing median PCT levels, CRP levels, and WBC counts on the preoperative day (PreOD), postoperative day 1 (POD 1), and postoperative day 3 (POD 3) between the infected and uninfected group. P-value determined with Mann-Whitney test. PCT, procalcitonin; CRP, C-reactive protein; WBC, white blood cell; IQR, interquartile range.

Figure 2

Kaplan-Meier curve analysis for predicting infection among models. A, PCT > 4.15 ng/ml (model 1). B, PCT > 4.15 ng/ml and CRP > 22.03 mg/l (model 2). C, PCT > 4.15 ng/ml and WBC > 15.3 × 10³/μl (model 2). D, PCT > 4.15 ng/ml, CRP > 22.03 mg/l, and WBC > 15.3 × 10³/μl (model 3).