Postoperative Serum Procalcitonin Level Can Be a Useful Marker of Bacterial Infection after Cardiac Surgery Utilizing Cardiopulmonary Bypass

Objectives. Procalcitonin level is generally undetectable from blood sample under normal physiological condition. However, its production can be greatly stimulated by the presence of various inflammatory responses, especially those caused by bacterial infection. We aimed to determine if postoperative procalcitonin level could be used to predict bacterial infection more promptly than bacterial culture results. Materials and Methods. We performed a retrospective case-control study by collecting postoperative procalcitonin as well as white blood cell level of patients undergoing cardiac surgery using cardiopulmonary bypass from electronic medical records of Ramathibodi Hospital between 1st January 2019 and 30th June 2023. Patients with pre-existing inflammatory syndromes or proven bacterial infection, who had been receiving preoperative treatment-dose antibiotics or steroids, who underwent non-elective surgery, and whose medical record data were lost or insufficiently recorded were excluded. Demographic data and operative details were also collected and reviewed. Results. From a total of 146 patients in our study, 42 patients developed proven postoperative bacterial infection. The level of procalcitonin with greatest association to postoperative bacterial infection from our study was 4.13 ng/dl on postoperative day 7. White blood cell level, however, was less predictive of bacterial infection. Conclusions. Procalcitonin level, when utilized alongside clinical presentation, proved to be useful as a predictor of bacterial infection during postoperative day 7. A larger, prospective trial of our continuing series would further strengthen our results.