Procalcitonin cannot be used as a biomarker of infection in heart surgery patients with acute kidney injury

Abstract

Purpose: We intended to assess how acute kidney injuy impacts on procalcitonin levels in cardiac surgery pa- tients, with or without infection, and whether procalcitonin might be used as a biomarker of infection in acute kidney injuy. Material and Methods: A case–control study was designed which included patients that had had cardiac surgery between January 2011 and January 2015. Every patient developing severe sepsis or septic shock (n = 122; 5.5%) was enrolled. In addition, consecutive cardiac surgery patients during 2013 developing systemic inflammatory response syndrome (n = 318) were enrolled. Those recruited 440 patients were divided into 2 groups, according to renal function. Results: Median procalcitonin levels were significantly higher during the 10 postoperative days in the acute kid- ney injury patients. Regression analysis showed that postoperatory day, creatinine, white blood cells and infec- tion were significantly (P b .0001) associated to serum procalcitonin level. In patients with creatinine ≥2, median procalcitonin levels were similar in infected and non-infected patients. Only when creatinine was less than 2 mg/L, the median procalcitonin levels were significantly higher in patients with infection, as compared to those with no infection. Conclusions: In acute kidney injuy patients, high procalcitonin levels are a marker of acute kidney injuy but will not be able to differentiate infected from non-infected patients.