Influence of major cardiopulmonary surgery on serum levels of procalcitonin and other inflammatory markers.

Procalcitonin is a marker of significant bacterial infection. With Food and Drug Administration approval of a new high-sensitive procalcitonin assay in the United States, we felt it would be important to assess its normal elevation and time characteristics, as compared to other inflammatory markers in patients undergoing routine cardiac surgery. This is a prospective observational study including consecutive patients after routine cardiac surgery. Blood was sampled preoperatively, immediately postoperatively and daily until discharge or to postoperative day five for measurement of blood markers of infection. Patients were classified into different groups based on the type of surgery (on-pump and off-pump) and progression of recovery (complicated and uncomplicated). Patients after coronary artery bypass grafting off-pump (n=61) had significantly lower mean (0.90 vs 1.13 µg/l, P=0.006) and peak (2.09 vs 2.35 µg/l, P=0.002) procalcitonin levels in the postoperative course compared to patients with either on-pump valve surgery alone, on-pump coronary artery bypass grafting alone (n=28) or valve surgery with coronary artery bypass grafting (n=16). In addition, mean and peak procalcitonin levels were significantly higher (P=0.004 and P=0.002 respectively) in the 60 patients with a complicated course. This study provides insights into 'normal' kinetics of a new high-sensitive procalcitonin assay after different types of cardiac surgery, and in patients with and without a complicated postoperative course. Our results suggest that using a single procalcitonin level to guide antibiotic therapy decisions during the early period after major cardiac surgery may not be useful and that monitoring its kinetic may be the preferred strategy.