Risk Factors and Outcomes of Acute Kidney Injury after Type A Aortic Dissection Surgery at A Tertiary Care Hospital

Objective: This study aimed to determine the risk factors predisposing to postoperative acute kidney injury (AKI) after type A aortic dissection repair; regarding patient-related, surgery-related and anesthesia-related factors.Material and Methods: A retrospective cohort study was conducted in patients who underwent type A aortic dissection repair under cardiopulmonary bypass (CPB), during the periods from January 2008 and December 2019. Patient-related, surgery-related and anesthesia-related factors were evaluated for association with AKI. AKI was defined by the Kidney Disease: Improving Global Outcomes criteria. The outcomes and mortality of AKI were also investigated.Results: Included were 95 patients, and the incidence of AKI was 65.3%. The 30-day mortality resulted only in the AKI group (14.9%). From multivariate logistic regression analysis, receiving intraoperative cryoprecipitate (odd ratio; OR 14.18; 95% confidence interval (CI), 3.27-61.5) and PRC transfusion (OR 1.001; 95% CI, 1.0005-1.002) in ICU were the risk factors for AKI. The protective factors were: higher preoperative serum bicarbonate levels (OR 0.83; 95% CI, 0.70- 0.99), higher volume of urine output during CPB (OR 0.71; 95% CI, 0.55-0.91) and higher immediate postoperative mean arterial pressure (OR 0.95; 95% CI, 0.92-0.98). Thirty-day mortality was significantly higher in the AKI group (14.5% vs 0%; p-value=0.025), and 15.0% of patients required renal replacement therapy.Conclusion: The higher level of three factors including preoperative serum bicarbonate levels (>23 mmol/l), volume of urine output during CPB and immediate postoperative mean arterial pressure (>81 mmHg) are likely to be the protective factors of AKI.