The Effect of Preoperative Creatinine Clearances on Postoperative Oxygenation in Coronary Artery Bypass Grafting: A Cohort Study

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.