Cardiac surgery group (control group)

Seventy-three post-cardiac surgery patients served as controls. These patients participated in pharmacological intervention trials performed by our research group in 2006–2014 [14–17]. The inclusion criteria were: (a) age >18 years, (b) elective cardiac surgery with cardiopulmonary bypass, (c) preoperative left ventricular ejection fraction ≥ 40%, and (d) preoperative serum creatinine within normal range. The exclusion criteria were: (a) postoperative need for inotropic support, (b) postoperative arrhythmias requiring treatment, (c) significant postoperative bleeding, (d) unsuccessful catheterization of the renal vein, and (e) postoperative AKI according to the AKIN criteria [18]. The baseline renal and systemic data of these patients, i.e. before pharmacological intervention, were used for comparison with those of the liver-transplanted group. Preoperative estimated glomerular filtration rate was calculated using the Modification of Diet in Renal Disease (MDRD) formula in all patients.

Anesthesia was induced by fentanyl and propofol. Before and after cardiopulmonary bypass, anesthesia was maintained with sevoflurane. During cardiopulmonary bypass, anesthesia was maintained with propofol. In the intensive care unit, the patients were sedated with propofol (3.8 ± 0.18 mg/kg/min) and morphine or fentanyl, and mechanically ventilated. Target central venous pressure (CVP) and target mean arterial pressure (MAP) were 5–10 mmHg and 70–80 mmHg, respectively. Postoperative hypovolemia was treated according to routine clinical practice with hydroxethyl starch (Venofundin, Braun, Germany) and crystalloid fluids (Ringer–Acetate®, Baxter Viaflo).