Cardiac surgery-associated acute kidney injury (CSA-AKI) is a serious complication of cardiac surgery and the second most common cause of AKI in the intensive care unit (ICU) after sepsis. CSA-AKI leads to the initiation of renal replacement therapy (RRT) in 1.2-3.0% of cardiac surgery cohorts and it is an independent predictor of chronic renal disease (CKD) and mortality. Moreover, cardiac surgery is characterized by an abrupt increase in inflammatory response. The scope of this study was to determine the utility of procalcitonin (PCT) and plasma IL-6 levels in predicting renal outcome and mortality in cardiac surgery patients.
We enrolled 122 cardiac surgery patients. Procalcitonin and plasma IL-6 levels were measured 48 hours after the surgical procedure. Primary endpoints were: adverse renal outcome, including acute kidney injury, defined as an increase in serum creatinine of 0.3 mg/dl in 48 hours after the procedure, worsening of preexisting CKD and the need for RRT; mortality, including in-hospital, 30-day and overall mortality. Secondary endpoints were: length of stay, bleeding and number of transfusions. Moreover, patients were divided into different groups according to extracorporeal circulation (ECC) time, type of surgery and number of transfusions.Procalcitonin and IL-6 levels were measured in all groups.
Procalcitonin was found to be a better predictor of adverse renal outcome than IL-6 (p=0.0326). Conversely, IL-6 resulted a better predictor of both 30 day and overall mortality than procalcitonin (p=0.0394 and 0.0207, respectively). Neither procalcitonin nor IL-6 levels were found to be good predictos of ICU stay and bleeding. No significant differences were found between procalcitonin and plasma IL-6 levels in terms of ECC, type of surgery and number of transfusions.
Procalcitonin may be considered a good predictor of adverse renal outcome in cardiac surgery patients, whereas IL-6 seems to possess a good predictive value for mortality in this population of patients.
