Elevated postoperative serum procalcitonin is not indicative of bacterial infection in cardiac surgical patients

BACKGROUND: Identifying infections early, commencing appropriate empiric antibiotic not only helps gain control early, but also reduces mortality and morbidity. Conventional cultures take about 5 days to identify infections. To identify the infections early biomarker like serum procalcitonin (SPC). AIMS: We studied the correlation of an elevated level of SPC and positive culture in elective adult patients undergoing cardiac surgery. METHODS: This prospective study was conducted from January to December 2013. SPC was checked in patients showing evidence of sepsis. Simultaneously, relevant culture was also undertaken. Correlation, specificity, and sensitivity of elevated SPC were checked. RESULTS: A total of 819 adult patients were included in the study. 43 of them had signs of infection and SPC levels were checked. Based on the level of SPC criteria, 10 patients were diagnosed as “nil”, out of them, 4 had culture-positive infections, 17 were suggested to have “mild infection,” 3 out those had culture positivity. None among the eleven patients suggested to have “moderate infection,” had a positive culture, and one among the five suggested to have a severe infection had a positive culture. The sensitivity was 50% and the specificity 17%. The positive predictive value was 12% and the negative predictive value 60%. CONCLUSIONS: We failed to elicit positive correlation between elevated SPC levels and postoperative infection in cardio surgical patients.