Due to the significant clinical problem of postoperative AKI, its quite frequent occurrence and its unfavorable prognosis, the main aim of the study was to evaluate selected preoperative and perioperative parameters, including the preoperative NTpro-BNP level, in terms of predicting the occurrence of AKI requiring renal replacement therapy in the early postoperative period. The gene discussed is NPPB; the disease is acute kidney injury.