Lack of renal protection of ultrafiltration during cardiac surgery: a randomized clinical trial.

AIM The objective of this study was to determine the intraoperative ultrafiltration effect on postoperative AKI. METHODS In this prospective randomized clinical trail, 159 patients scheduled for elective cardiac surgery, were randomly assigned to either hemofilter (N.=87) or control group (N.=72). The primary and secondary outcomes were AKI (defined as ≥50% increase in the serum creatinine level) and increased urinary neutrophil gelatinase-associated lipocalin (NGAL) in the postoperative period, respectively. RESULTS The two groups were similar with respect to comorbidities and also surgical procedure, except ultrafiltration. The incidence of AKI was equal in the both groups (11% vs. 5%, P=0.2, respectively). Creatinine increased after surgery (P=0.00) without significant differences between the both groups (P=0.2). Urinary NGAL also showed no significant difference between the groups. Age, euroscore, hyperlipidemia, pulmonary disease and urinary volume during operation correlated with the development of AKI. Postoperative blood loss was less in the hemofilter than control group (820±550 mL vs. 1100±630 mL, P=0.04). There was no difference in the length of intubation and stay in intensive care unit. CONCLUSION Routine use of ultrafiltration during cardiac surgery offers no advantages in renal protection and reduction of AKI incidence.