Every category was tested for the following variables: gender, age, duration of in-hospital stay, AKI stage according to KDIGO [2], initial, peak, and last serum creatinine, initial, peak, and last serum sodium and potassium concentrations, respectively, initial and peak NT-proBNP and CRP, vasopressor therapy, invasive ventilation, arterial hypertension, diabetes mellitus, obesity, preexisting coronary artery disease (CAD) and chronic heart failure (CHF), chronic obstructive pulmonary disease (COPD), hyperuricemia, and history of neoplasia. Here, NPPB is linked to chronic obstructive pulmonary disease.