Assessment of the accuracy of procalcitonin to diagnose postoperative infection after cardiac surgery.
BACKGROUND
Cardiopulmonary bypass induces a nonspecific inflammatory response. Procalcitonin has been advocated as a specific biomarker for infection. The authors studied the accuracy of procalcitonin to diagnose postoperative infection after cardiac surgery and compared it with those of C-reactive protein, white blood cell count, and interleukins 6 and 8.


METHODS
The authors prospectively included 100 patients scheduled to undergo elective cardiac procedures with cardiopulmonary bypass. Blood samples were taken before surgery and each day over the 7-day postoperative period, and measurement of procalcitonin, C-reactive protein, white blood cell count, and interleukins 6 and 8 were performed. Diagnosis of infection was performed by a blinded expert panel. Data are expressed as value [95% confidence interval].


RESULTS
Infection was diagnosed in 16 patients. Procalcitonin was significantly higher in infected patients, with a peak reached on the third postoperative day. Only the areas under the receiver operating curve of procalcitonin (0.88 [0.71-0.95]) and C-reactive protein (0.72 [0.58-0.82]) were significantly different from the no-discrimination curve, and that of procalcitonin was significantly different from those of C-reactive protein, white blood cell count, and interleukins 6 and 8. A procalcitonin value greater than 1.5 ng/ml beyond the second day diagnosed postoperative infection with a sensitivity of 0.93 [0.70-0.99] and a specificity of 0.80 [0.70-0.87]. Procalcitonin was significantly higher in patients who died (27.5 [1.65-40.5] vs. 1.2 [0.7-1.5] ng/ml; P < 0.001).


CONCLUSIONS
Procalcitonin is a valuable marker of bacterial infections after cardiac surgery.
Department of Anesthesiology and Critical Care, Military Hospital, Tunis, Tunisia.
Mohamed Adel
MA
Jebali
Pierre
P
Hausfater
Zoubeir
Z
Abbes
Zied
Z
Aouni
Bruno
B
Riou
Mustapha
M
Ferjani
D001424:Bacterial Infections / Q000097:blood / Q000175:diagnosis*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D017558:Elective Surgical Procedures / Q000379:methods; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D016209:Interleukin-8 / Q000097:blood; D007958:Leukocyte Count / Q000379:methods; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000097:blood / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors
D015415:Biomarkers; C000606589:CALCA protein, human; D015850:Interleukin-6; D016209:Interleukin-8; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide