Procalcitonin in the Early Course Post Pediatric Cardiac Surgery

Robert Zant, MD; Christian Stocker, MD, FMH (CH), FCICM; Luregn Jan Schlapbach, MD, FCICM; Sara Mayfield, BHScNurs; Tom Karl, MD, FRACS; Andreas Schibler, MD, FMH (CH), FCICM


Pediatr Crit Care Med. 2016;17(7):624-629. 

In This Article

Materials and Methods

Study Design

This was a prospective single-center observational study performed at Queensland's referral center for pediatric cardiac surgery located at the Mater Children`s Hospital, Brisbane, Australia. Patients were aged 0–16 years and were included following cardiac surgery between January 1, 2013, and December 31, 2013. The study was approved by the local Institutional Review Board (Mater Health Services; HREC 2013_02). Waiver of informed consent was approved by the institutional review board.

Preoperative risk factors and risk assessment scores were prospectively assessed using Basic/Comprehensive Aristotle Complexity and Risk Adjusted Congenital Heart Surgery Scores.[8] Further preoperative risk factors were defined as mechanical ventilation prior to surgery, myocardial dysfunction, seizures, stroke or intracranial hemorrhage, necrotizing enterocolitis, and renal failure. In addition, cardiopulmonary bypass (CPB) time, aortic cross clamp time, and serum lactate at admission were prospectively collected.

All children were routinely treated for 24 hours post bypass surgery with cefazolin (25 mg/kg 8 hourly). Procalcitonin was measured in all patients at admission from operating theater to PICU, and on postoperative day 1 and 2 (POD0, POD1, and POD2, respectively) as long as the children remained in PICU. All blood samples were taken from the arterial line. Quantitative measurements of procalcitonin were performed with the Advia Centaur BRAHMS PCT-test kit (B-R-A-H-M-S AG Hennigsdorf, Germany and Siemens Medical Solutions, NY). The analytic sensitivity of this assay is 0.01 ng/mL (range, 0.01–75 ng/mL). As procalcitonin is physiologically elevated in the first 48 hours after birth, the test's adult reference range applies from day 3 after birth.[9] The results of the procalcitonin levels were not known to the treating clinicians during the stay in PICU.

Outcome Data

A major adverse event (MAE) was defined as cardiac arrest, need for postoperative extracorporeal life support or death within 3 months of cardiac surgery. MAE were prospectively recorded as a part of internal quality control requirements. Further outcome variables included length of stay (LOS) in PICU, postoperative renal failure requiring temporary dialysis, duration on mechanical ventilation, and duration of inotropic support.

Statistical Analyses

Linear regression models in interval scaled variables and Mann-Whitney U tests in nominal-scaled variables were used for testing influence variables on procalcitonin, for testing differences in procalcitonin clearance, and for assessment of procalcitonin as a predictor of outcome. Multiple linear regression analysis was performed to determine which associations are unique to procalcitonin. Receiver operating characteristic (ROC) curves were additionally calculated to evaluate the discriminative power of procalcitonin values at admission as a predictor of outcome. Optimal cutoff values were determined by the Youden index. Mean and range and median and interquartile range are reported. All analyses were performed with IBM SPSS Statistics for Windows, version 21.0 (IBM, Armonk, NY).