Clinical trials

Acute kidney injury (AKI) is a significant postoperative complication. Risk factors for AKI include impaired renal perfusion, decreased functional renal reserve, as well as advanced age, peripheral arterial disease, diabetes mellitus, renovascular disease and congestive heart failure. Mean arterial pressure (MAP) below 55-60 mmHg has been associated with postoperative AKI. Traditional diagnostic criteria for AKI include increased serum creatinine levels and oliguria. However, creatinine levels do not rise until more than half of renal function is lost. Serum and urine NGAL levels rise earlier-within 24-48 hours-making it a promising early biomarker. In our study, hypotension is defined as systolic blood pressure \<100 mmHg or a \>30% decrease in MAP. Patients requiring ephedrine under these conditions will be evaluated as the hypotension group and compared with non-hypotensive patients in terms of NGAL, BUN (blood urea nitrogen), creatinine, and GFR (Glomerular Filtration Rate) values at baseline and at the 4th postoperative hour.