Postoperative Acute Kidney Injury and Efficacy of Continuous Hemodiafiltration after Cardio-Thoracic Surgery

Abstract

Background and Purpose : Patients who undergo cardiac and thoracic vascular surgery are known to have a high risk of developing acute kidney injury (AKI). The incidence of post-operative acute renal failure and the utility of continuous hemodiafiltration (CHDF) for acute renal failure following cardiovascular surgery was determined. Subjects and Methods : Of the 321 subjects who underwent cardiac and thoracic vascular surgery accompanied by an open thoracotomy from January 2014 to August 2017, 303 patients were included in this study after excluding those who received maintenance dialysis and those treated with PCPS. Patients were grouped based on the GFR classification of CKD severity (preoperative eGFR values : G1 : ≥90, G2 : <90, G3a : <60, G3b : <45, G4 : <30, G5 : <15) and patient records were retrospectively examined. Results : The total incidence of AKI was 30.7%. In comparison with G1 and G2, the AKI incidence rate was significantly higher (p<0.01) in G3a, G3b, G4, and G5 patients who displayed preoperative renal dysfunction. Upon multivariate analysis, preoperative eGFR values were shown to be a predictor of post-operative AKI avoidance with a cutoff value of 56 ml/min/1.73 m² (odds ratio = 4.104, AUC = 0.6954). The post-operative CHDF introduction rate was 3.6%. After introduction of CHDF, patient urine volume and body blood pressure significantly increased (p < 0.01). In 2 cases, a rapid increase of urine volume (2.5 ml/kg/h, 1.8 ml/kg/h) was observed within 1 h after the induction of CHDF. Conclusions : A high rate of post-operative AKI onset occurs in cardiac and thoracic surgery cases. Upon early introduction of post-operative CHDF, prompt recovery of renal function and stabilization of circulatory dynamics can be expected.