The effects of 7.2% Nacl/6% HES 200/0.5 on renal function in on-pump coronary artery bypass graft surgery patients: a randomised blinded study

Introduction: The influence of medium molecular weight hydroxyethyl starches (HES) on development of acute kidney injury (AKI) in cardiac surgery patients is not clearly defined. The aim of the study was to evaluate the effect of 7.2% NaCl/6% HES 200/0.5 (HSH) on kidney integrity in patients undergoing on-pump CABG surgery. Methods: After Ethics Committee approval and informed consent, patients with glomerular filtration rate > 90 ml · min–1 were randomly assigned to receive once either HSH (HSH group, n = 20) or 0.9% NaCl (control group, n = 20) at a dose of 4 ml · kg–1 for 30 min after anaesthesia induction for fluid resuscitation. Primary end points were: screatinine (sCr), s-cystatin C (sCys-C), urine neutrophil gelatinase-associated lipocalin (uNGAL), measured at baseline, 5 min, 2 h, 4 h, and 24 h after cardiopulmonary bypass (CPB); as well as diuresis at the end of surgery and at 24 h after CPB. Peri-operative fluid management was guided by global end di astolic volume (PiCCO plus system). Results are given as median with IQR. Statistical testing was performed using Mann-Whitney’s U test with MedCalc v12.1.4. Results: There were no differences in perioperative haemodynamics and baseline renal markers. Of the 40 patients analysed, only 2 patients in the control group developed Rcriterion of AKI at 24 h after CPB. The values of sCys-C were greater in the control group compared with the HSH group at 5 min, 2 h, and 4 h CPB. Significantly decreased uNGAL concentration was in the HSH group at 24 h after CPB. Diuresis was greater in the HSH group compared with the control group at the end of surgery (P = 0.01) and at 24 h after CPB (P < 0.01) (see Table 1). Discussion: The use of HSH for fluid resuscitation at a dose of 4 ml · kg–1 in patients undergoing on-pump CABG surgery did not alter renal function. Moreover, less tubular damage was identified after infusion of HSH. In further controlled studies it has to be investigated whether HSH impairs kidney integrity in high risk cardiac patients.