6.3 Post-operative
Due to the complex nature of CS-AKI, it has been suggested that incorporating a combination of interventions would provide greater benefit to cardiac patients postoperatively, rather than a single intervention alone. In 2017, a single-center trial, PrevAKI RCT, was conducted to evaluate the use of KDIGO guidelines in reducing the incidence of postoperative AKI. This study selected high-risk patients with a urinary (TIMP-2)/(IGFBP7) ratio greater than 0.3.46 Evidence from preliminary data demonstrated that the KDIGO-based bundle of care helped reduce the incidence and severity of postoperative AKI in these patients. Recommendations include avoiding nephrotoxic drugs, preventing hyperglycaemia, and optimizing fluid status and haemodynamic.46 KDIGO guidelines were also investigated in the ELAIN trial, another single-center RCT, which revealed that early use of RRT led to a decrease in mechanical ventilation time and hospital inpatient duration, as well as an increased rate of recovery by day 90 compared to late RRT use postoperatively.48
Future Direction
Managing and minimizing the risk of CS-AKI and long-term renal complications remains a challenging problem. Several clinical trials exploring preventative interventions have been attempted over the years with conflicting results. A potential reason for these inconsistencies could be due to the lack of phenotyping and risk stratification among cardiac surgery patients. Through the use of clinical features (e.g. pre-existing comorbidities, preoperative glomerular filtration rate), genetic, blood and urine biomarkers, patients at higher risk of CS-AKI could benefit from earlier diagnosis and timely management.41 According to findings from the TRIBE-AKI study, there is a potential use for blood and urine biomarkers to determine the risk of CKD progression among cardiac surgery patients. Elevated levels of these biomarkers in the postoperative setting may improve management and encourage closer outpatient follow-up to those at greater CKD risk.49, 50