Wim Vandenberghe

Introduction Previous studies demonstrated that the implementation of the Kidney Disease Improving Global Outcomes (KDIGO) guideline-based bundle, consisting of different supportive measures in patients at high risk for acute kidney injury (AKI), might reduce rate and severity of AKI after surgery. However, the effects of the care bundle in broader population of patients undergoing surgery require confirmation. Methods and analysis The BigpAK-2 trial is an international, randomised, controlled, multicentre trial. The trial aims to enrol 1302 patients undergoing major surgery who are subsequently admitted to the intensive care or high dependency unit and are at high-risk for postoperative AKI as identified by urinary biomarkers (tissue inhibitor of metalloproteinases 2*insulin like growth factor binding protein 7 (TIMP-2)*IGFBP7)). Eligible patients will be randomised to receive either standard of care (control) or a KDIGO-based AKI care bundle (intervention). The primary endpoint is the incidence of moderate or severe AKI (stage 2 or 3) within 72 hours after surgery, according to the KDIGO 2012 criteria. Secondary endpoints include adherence to the KDIGO care bundle, occurrence and severity of any stage of AKI, change in biomarker values during 12 hours after initial measurement of (TIMP-2)*(IGFBP7), number of free days of mechanical ventilation and vasopressors, need for renal replacement therapy (RRT), duration of RRT, renal recovery, 30-day and 60-day mortality, intensive care unit length-of-stay and hospital length-of-stay and major adverse kidney events. An add-on study will investigate blood and urine samples from recruited patients for immunological functions and kidney damage. Ethics and dissemination The BigpAK-2 trial was approved by the Ethics Committee of the Medical Faculty of the University of Münster and subsequently by the corresponding Ethics Committee of the participating sites. A study amendment was approved subsequently. In the UK, the trial was adopted as an NIHR portfolio study. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and will guide patient care and further research. Trial registration number NCT04647396.

Acute kidney injury (AKI) is common after pediatric cardiac surgery (CS). Several urine biomarkers have been validated to detect AKI earlier. The objective of this study was to evaluate urine CHI3L1, NGAL, TIMP-2, IGFBP7, and NephroCheck^® as predictors for AKI ≥ 1 in pediatric CS after 48 h and AKI ≥ 2 after 12 h. Pediatric patients (age < 18 year; body weight ≥ 2 kg) requiring CS were prospectively included. Urine CHI3L1, NGAL, TIMP-2, IGFBP7, and NephroCheck^® were measured during surgery and intensive care unit (ICU) stay and corrected for urine dilution. One hundred and one pediatric patients were included. AKI ≥ 1 within 48 h after ICU admission occurred in 62.4% and AKI ≥ 2 within 12 h in 30.7%. All damage biomarkers predicted AKI ≥ 1 within 48 h after ICU admission, when corrected for urine dilution: CHI3L1 (AUC-ROC: 0.642 (95% CI, 0.535–0.741)), NGAL (0.765 (0.664–0.848)), TIMP-2 (0.778 (0.662–0.868)), IGFBP7 (0.796 (0.682–0.883)), NephroCheck^® (0.734 (0.614–0.832)). Similarly, AKI ≥ 2 within 12 h was predicted by all damage biomarkers when corrected for urine dilution: uCHI3L1 (AUC-ROC: 0.686 (95% CI, 0.580–0.780)), NGAL (0.714 (0.609–0.804)), TIMP-2 (0.830 (0.722–0.909)), IGFBP7 (0.834 (0.725–0.912)), NephroCheck^® (0.774 (0.658–0.865)). After pediatric cardiac surgery, the damage biomarkers urine CHI3L1, NGAL, TIMP-2, IGFBP7, and NephroCheck^® reliably predict AKI after correction for urine dilution.

Background: Acute kidney injury (AKI) has been reported as a frequent complication of critical COVID-19. We aimed to evaluate the occurrence of AKI and use of kidney replacement therapy (KRT) in critical COVID-19, to assess patient and kidney outcomes and risk factors for AKI and differences in outcome when the diagnosis of AKI is based on urine output (UO) or on serum creatinine (sCr). Methods: Multicenter, retrospective cohort analysis of patients with critical COVID-19 in seven large hospitals in Belgium. AKI was defined according to KDIGO within 21 days after ICU admission. Multivariable logistic regression analysis was used to explore the risk factors for developing AKI and to assess the association between AKI and ICU mortality. Results: Of 1286 patients, 85.1% had AKI, and KRT was used in 9.8%. Older age, obesity, a higher APACHE II score and use of mechanical ventilation at day 1 of ICU stay were associated with an increased risk for AKI. After multivariable adjustment, all AKI stages were associated with ICU mortality. AKI was based on sCr in 40.1% and UO in 81.5% of patients. All AKI stages based on sCr and AKI stage 3 based on UO were associated with ICU mortality. Persistent AKI was present in 88.6% and acute kidney disease (AKD) in 87.6%. Rapid reversal of AKI yielded a better prognosis compared to persistent AKI and AKD. Kidney recovery was observed in 47.4% of surviving AKI patients. Conclusions: Over 80% of critically ill COVID-19 patients had AKI. This was driven by the high occurrence rate of AKI defined by UO criteria. All AKI stages were associated with mortality (NCT04997915).

Introduction: Acute kidney injury occurs in up to one third of patients after cardiac surgery and is an important contributor for adverse outcome. Previous research has demonstrated the benefit of a bundle of preventive measurements to reduce AKI in a subgroup of patients with high risk for AKI development. Urinary stress biomarkers [TIMP-2]*[IGFBP7] are used to identify these patients who are at risk for AKI. The trial aims to investigate the potential discrepancy between biomarker results and clinical estimation of occurrence of AKI on ICU in clinical practice. Methods and analysis: We plan to include 100 adult patients after cardiac surgery with cardiopulmonary bypass in a prospective, single center clinical trial. After cardiac surgery, different type of healthcare professional in ICU will provide a prediction of AKI occurrence and severity in the next 48 hours by filling in a questionnaire just before and after [TIMP-2]*[IGFBP7] biomarker analysis. Primary, this trial investigates the potential discrepancy in AKI prediction between clinical estimation by healthcare providers, biomarker results, and previous described score systems. Secondly, the impact of knowledge of the biomarker result on the quality of prediction by healthcare providers will be evaluated. Ethics and dissemination: This prospective, single center study has been approved by the medical ethical committee of the Ghent University Hospital (28 ^th May 2019, trial registration number B670201939991). Informed consent was obtained for patients and healthcare providers. Summary strength and limitations: - Influence of knowledge of a kidney biomarker on healthcare providers’ assessment of risk for AKI in clinical setting - Different types of healthcare providers with various expertise - It is a single center study with limited number of patients

For decades, when contrast agents are administrated, physicians have been concerned because of the risk of inducing acute kidney injury (AKI). Recent literature questions the existence of AKI induced by contrast, but animal studies clearly showed harmful effects. The occurrence of contrast-associated AKI was likely overestimated in the past because of confounders for AKI. Several strategies have been investigated to reduce contrast-associated AKI but even for the most important one, hydration, there are conflicting data. Even if the occurrence rate of contrast-associated AKI is low, AKI is related to worse outcomes. Therefore, besides limiting contrast agent usage, general AKI preventive measurements should be applied in at-risk patients.

Background: We evaluated the epidemiology and outcome of acute kidney injury (AKI) in patients with cardiorenal syndrome type 1 (CRS-1) and its subgroups: acute heart failure (AHF), acute coronary syndrome (ACS) and after cardiac surgery (CS). Summary: We performed a systematic review and meta-analysis. CRS-1 was defined by AKI (based on RIFLE, AKIN and KDIGO), worsening renal failure (WRF) and renal replacement therapy (RRT). We investigated the three most common clinical causes of CRS-1: AHF, ACS and CS. Out of 332 potential papers, 64 were eligible - with AKI used in 41 studies, WRF in 25 and RRT in 20. The occurrence rate of CRS-1, defined by AKI, WRF and RRT, was 25.4, 22.4 and 2.6%, respectively. AHF patients had a higher occurrence rate of CRS-1 compared to ACS and CS patients (AKI: 47.4 vs. 14.9 vs. 22.1%), but RRT was evenly distributed among the types of acute cardiac disease. AKI was associated with an increased mortality rate (risk ratio = 5.14, 95% CI 3.81-6.94; 24 studies and 35,227 patients), a longer length of stay in the intensive care unit [LOS_ICU] (median duration = 1.37 days, 95% CI 0.41-2.33; 9 studies and 10,758 patients) and a longer LOS in hospital [LOS_hosp] (median duration = 3.94 days, 95% CI 1.74-6.15; 8 studies and 35,227 patients). Increasing AKI severity was associated with worse outcomes. The impact of CRS-1 defined by AKI on mortality was greatest in CS patients. RRT had an even greater impact compared to AKI (mortality risk ratio = 9.2, median duration of LOS_ICU = 10.6 days and that of LOS_hosp = 20.2 days). Key Messages: Of all included patients, almost one quarter developed AKI and approximately 3% needed RRT. AHF patients experienced the highest occurrence rate of AKI, but the impact on mortality was greatest in CS patients.

In this paper, we examine the capabilities of switched Ethernet for building wireless mesh networks (WMNs) and more specific for the support of fast moving users. We motivate that switched Ethernet with wireless extensions is a promising auto-configurable WMN technology. An inherent Ethernet feature, topology modification according to the actual link rates, will be used to avoid poor wireless links in the active topology. We demonstrate that fast recovery is feasible in a WMN by extending the standard spanning tree protocols. Simulations and analytical results will reveal some basic differences if the wired links of switched Ethernet are replaced by wireless links and this leads to a parameter evaluation of the IEEE 802.11e protocol for optimizing the bandwidth usage of the wireless medium