In cardiac surgery practice, systemic inflammatory response (SIRS) is a clinical condition that develops secondary to cardiopulmonary bypass (CPB) and increases mortality and morbidity. Postoperative infection among patients undergoing cardiac surgery, manifests itself in a way similar to SIRS and also increases mortality. Early diagnosis and treatment of infectious complications reduce mortality and morbidity. Procalcitonin, the precursor of calcitonin, is a  specificity and sensitivity for early detection of bacterial sepsis have recently been confirmed by multiple studies Its serum level exceeds that level when postoperative infection or sepsis develops, depending on the severity of the either clinical condition. Despite being elevated in the event of bacterial and fungal infections; it is not affected by viral infections. Monitoring postoperative serum PCT kinetics is useful for making an early diagnosis of postoperative complications. Serum PCT should be routinely monitored in all patients undergoing cardiac surgery. PCT levels failing to drop by 24 hours postoperatively, or

those exceeding 5 ng/ml, should be interpreted in favor of infection or any postoperative

complication. Its marked superiority over CRP and WBC allows making a timely diagnosis of infectious complications and commencing antibiotic therapy without delay. 

Serum PCT level is an important biomarker that offers promise for routine use to reduce postoperative morbidity and mortality after cardiac surgery.