Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 56 12 2019 01 22 750 756 EN Fardin Yousefshahi Department of Anesthesiology, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran. Khosro Barkhordari Department of Anesthesia and Critical Care, Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Leila Mahdifar School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Abbas Salehiomran Department of Cardiac Surgery, Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Hossein Majedi Department of Anesthesiology, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran . AND Brain and Spinal Cord Injury Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran. Jayran Zebardast Department of Cognitive Linguistics, Institute for Cognitive Science Studies (ICSS), Tehran, Iran. 2018 01 14 2018 11 19  End-stage kidney disease has a high prevalence in patients undergone Coronary Artery Bypass Grafting (CABG) and could cause a wide spectrum of morbidities, due to deep water and electrolyte or acid-base impairments. The aim of this study was to assess the effect of low Creatinine Clearances (ClCr) on arterial oxygenation defect, as common post-CABG morbidity. The study was conducted as a prospective cohort, the pure on pump CABG patients were grouped based on their preoperative ClCr to groups A (ClCr≥60) and B (ClCr<60). Postoperatively, the PaO2/FiO2 values in 1 hour after ICU admission and 4 hours after extubation, intubation time duration, duration of ICU stay and high concentration oxygen demand were compared. Among 229 patients who remain in the study, 121 were in group A, and 108 in B group. Except for age, weight, height, BMI, and pump time, other demographic and independent variables were similar between two groups. The higher values of PaO2/FiO2 and PaO2, 1 hour after ICU admission and 4 hours after extubation in group B, were not statistically significant, while SpO2 value, 1 hour after ICU admission was higher in group B (98.19±1.37) in compare with group A (97.78±1.57) (P=0.040). Intubation time duration (10.85 in A vs. 12.79 in B; P=0.306), duration of ICU stay (39.04 in A vs. 43.09 in B; P=0.114) and high concentration oxygen demand (2.5% in A vs. 3.8% in B; P=0.089) were similar between groups of study. Lower Preoperative ClCr values do not deteriorate post-CABG arterial oxygenation. https://acta.tums.ac.ir/index.php/acta/article/view/6961