Perioperative intravenous amino acid infusion for nephroprotection in patients with chronic kidney disease undergoing cardiac surgery with cardiopulmonary bypass: a randomized placebo-controlled single-blinded trial

INTRODUCTION: Acute kidney injury (AKI) is one of the most severe complications of cardiac surgery, especially in patients with chronic kidney disease (CKD), where incidence reaches 40–50 %. Severe forms requiring renal replacement therapy (RRT) are linked to mortality up to 60 % and faster CKD progression. Functional renal reserve is a promising tool for AKI prevention, but its compensatory mechanisms may be impaired in CKD. OBJECTIVE: To assess the effect of perioperative infusion of an amino acid solution on renal function in CKD patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). MATERIALS AND METHODS: This randomized, single-blinded, placebo-controlled trial included 132 patients. Intervention group (n = 66): Aminoven 10 %, 2 g/kg/day; control (n = 66): Sterofundin, 20 ml/kg/day. Infusion started after anesthesia induction and continued for 24 hours. The primary endpoint was change in estimated glomerular filtration rate (eGFR); secondary endpoints were AKI incidence and severity, urine output, diuretic use, and hospital stay. RESULTS: Amino acid infusion improved renal function: eGFR 64 [54; 77] vs. 60 [44; 74] ml/min/1.73 m² (p = 0.0005), creatinine 96 [81; 115] vs. 101 [84; 126] µmol/L (p = 0.0018), urine output 2100 [1800; 2400] vs. 1900 [1700; 2200] ml/day (p = 0.0004). AKI incidence was 23.9 vs. 34.9 % (p = 0.185), but severe AKI (KDIGO 2–3) occurred less often: 7.6 vs. 21.2 % (p = 0.045). AKI duration was shorter (3.0 vs. 5.5 days, p = 0.038). Furosemide use was lower (30.3 vs. 48.2 %; p < 0.0001). Hospitalization was reduced (19.5 [15.3; 25.0] vs. 23 [19.3; 30.8] days; p = 0.045). RRT was infrequent (3.03 vs. 4.55 %; p = 0.648). CONCLUSIONS: Perioperative amino acid infusion in CKD patients improved renal function, lessened AKI severity and duration, reduced diuretic need, and shortened hospital stay, supporting its role as a nephroprotective strategy in cardiac surgery with CPB.