BACKGROUND: Prospective, single-center trials have shown that the implementation of the Kidney Disease: Improving Global Outcomes (KDIGO) recommendations in high-risk patients significantly reduced the development of acute kidney injury (AKI) after surgery. We sought to evaluate the feasibility of implementing a bundle of supportive measures based on the KDIGO guideline in high-risk patients undergoing cardiac surgery in a multicenter setting in preparation for a large definitive trial. METHODS: In this multicenter, multinational, randomized controlled trial, we examined the adherence to the KDIGO bundle consisting of optimization of volume status and hemodynamics, functional hemodynamic monitoring, avoidance of nephrotoxic drugs, and prevention of hyperglycemia in high-risk patients identified by the urinary biomarkers tissue inhibitor of metalloproteinases-2 [TIMP-2] and insulin growth factor-binding protein 7 [IGFBP7] after cardiac surgery. The primary end point was the adherence to the bundle protocol and was evaluated by the percentage of compliant patients with a 95% confidence interval (CI) according to Clopper-Pearson. Secondary end points included the development and severity of AKI. RESULTS: In total, 278 patients were included in the final analysis. In the intervention group, 65.4% of patients received the complete bundle as compared to 4.2% in the control group (absolute risk reduction [ARR] 61.2 [95% CI, 52.6-69.9]; P < .001). AKI rates were statistically not different in both groups (46.3% intervention versus 41.5% control group; ARR −4.8% [95% CI, −16.4 to 6.9]; P = .423). However, the occurrence of moderate and severe AKI was significantly lower in the intervention group as compared to the control group (14.0% vs 23.9%; ARR 10.0% [95% CI, 0.9-19.1]; P = .034). There were no significant effects on other specified secondary outcomes. CONCLUSIONS: Implementation of a KDIGO-derived treatment bundle is feasible in a multinational setting. Furthermore, moderate to severe AKI was significantly reduced in the intervention group. (Anesth Analg XXX;XXX:00-00) KEY POINTS• Question: Is it feasible to implement a bundle of supportive measures in high-risk patients undergoing cardiac surgery in a multinational setting? • Findings: In this multicenter randomized clinical trial, we found that the implementation of the Kidney Disease: Improving Global Outcomes (KDIGO) bundle is feasible in a multinational setting and that these supportive measures significantly reduced the occurrence of moderate and severe acute kidney injury (AKI). • Meaning: The findings underpin the need for a definitive trial to evaluate whether the KDIGO bundle reduces the occurrence of AKI in high-risk patients after cardiac surgery.

IntroductionAcute kidney injury (AKI) is a frequent complication after cardiac surgery with adverse short-term and long-term outcomes. Although prevention of AKI (PrevAKI) is strongly recommended, the optimal strategy is uncertain. The Kidney Disease: Improving Global Outcomes (KDIGO) guideline recommended a bundle of supportive measures in high-risk patients. In a single-centre trial, we recently demonstrated that the strict implementation of the KDIGO bundle significantly reduced the occurrence of AKI after cardiac surgery. In this feasibility study, we aim to evaluate whether the study protocol can be implemented in a multicentre setting in preparation for a large multicentre trial.Methods and analysisWe plan to conduct a prospective, observational survey followed by a randomised controlled, multicentre, multinational clinical trial including 280 patients undergoing cardiac surgery with cardiopulmonary bypass. The purpose of the observational survey is to explore the adherence to the KDIGO recommendations in routine clinical practice. The second phase is a randomised controlled trial. The objective is to investigate whether the trial protocol is implementable in a large multicentre, multinational setting. The primary endpoint of the interventional part is the compliance rate with the protocol. Secondary endpoints include the occurrence of any AKI and moderate/severe AKI as defined by the KDIGO criteria within 72 hours after surgery, renal recovery at day 90, use of renal replacement therapy (RRT) and mortality at days 30, 60 and 90, the combined endpoint major adverse kidney events consisting of persistent renal dysfunction, RRT and mortality at day 90 and safety outcomes.Ethics and disseminationThe PrevAKI multicentre study has been approved by the leading Research Ethics Committee of the University of Münster and the respective Research Ethics Committee at each participating site. The results will be used to design a large, definitive trial.Trial registration numberNCT03244514.

Purpose The incidence, patient features, risk factors and outcomes of surgery-associated postoperative acute kidney injury (PO-AKI) across different countries and health care systems is unclear. Methods We conducted an international prospective, observational, multi-center study in 30 countries in patients undergoing major surgery (> 2-h duration and postoperative intensive care unit (ICU) or high dependency unit admission). The primary endpoint was the occurrence of PO-AKI within 72 h of surgery defined by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Secondary endpoints included PO-AKI severity and duration, use of renal replacement therapy (RRT), mortality, and ICU and hospital length of stay. Results We studied 10,568 patients and 1945 (18.4%) developed PO-AKI (1236 (63.5%) KDIGO stage 1500 (25.7%) KDIGO stage 2209 (10.7%) KDIGO stage 3). In 33.8% PO-AKI was persistent, and 170/1945 (8.7%) of patients with PO-AKI received RRT in the ICU. Patients with PO-AKI had greater ICU (6.3% vs. 0.7%) and hospital (8.6% vs. 1.4%) mortality, and longer ICU (median 2 (Q1-Q3, 1–3) days vs. 3 (Q1-Q3, 1–6) days) and hospital length of stay (median 14 (Q1-Q3, 9–24) days vs. 10 (Q1-Q3, 7–17) days). Risk factors for PO-AKI included older age, comorbidities (hypertension, diabetes, chronic kidney disease), type, duration and urgency of surgery as well as intraoperative vasopressors, and aminoglycosides administration. Conclusion In a comprehensive multinational study, approximately one in five patients develop PO-AKI after major surgery. Increasing severity of PO-AKI is associated with a progressive increase in adverse outcomes. Our findings indicate that PO-AKI represents a significant burden for health care worldwide. Supplementary Information The online version contains supplementary material available at 10.1007/s00134-023-07169-7.

Dear Editor,Acute kidney injury (AKI) remains a common and significant complication in critically ill patients. As no curative treatment exists, prevention of AKI is paramount, especially in high-risk patients. Several randomized controlled trials suggest that a biomarker-guided implementation of the Kidney Disease Improving Global Outcomes (KDIGO) care bundle reduces the incidence of AKI postoperatively [1][2][3]. Implementation of this care bundle is recommended in high-risk patients after cardiac surgery [4]. This comprises regular monitoring of kidney function, hemodynamic optimization, and consideration of advanced hemodynamic monitoring, as well as avoidance of hyperglycemia, nephrotoxic drugs, and radiocontrast agents, if possible.So far, the impact of each individual component of the bundle is unclear. Better understanding would enable prioritization, resource-allocation and clinical management of those at high risk of AKI. To investigate the treatment effects of individual bundle components, we combined data of the two PrevAKI-trials including 554 cardiac surgery patients at high risk for AKI, as defined by elevated urinary biomarkers TIMP2*IGFBP7 [1,2]. Patients were randomized to standard care versus implementation of the care bundle (Supplementary S1).Univariate logistic regression of the bundle's components was performed as a risk factor analysis of the whole cohort. Following this, individual treatment effects were analyzed, using the same method for the intervention group only (Fig. 1a). Hypotension, low cardiac