Publications by authors named "Nicholas M Selby"

100 Publications

Multiparametric MRI assessment of renal structure and function in acute kidney injury and renal recovery.

Clin Kidney J 2021 Aug 10;14(8):1969-1976. Epub 2021 Feb 10.

Centre for Kidney Research and Innovation, University of Nottingham, Royal Derby Hospital Campus, Nottingham, UK.

Background: Acute kidney injury (AKI) is associated with a marked increase in mortality as well as subsequent chronic kidney disease (CKD) and end-stage kidney disease. We performed multiparametric magnetic resonance imaging (MRI) with the aim of identifying potential non-invasive MRI markers of renal pathophysiology in AKI and during recovery.

Methods: Nine participants underwent inpatient MRI scans at time of AKI; seven had follow-up scans at 3 months and 1 year following AKI. Multiparametric renal MRI assessed total kidney volume (TKV), renal perfusion using arterial spin labelling, T mapping and blood oxygen level-dependent (BOLD) R* mapping.

Results: Serum creatinine concentration had recovered to baseline levels at 1-year post-AKI in all participants. At the time of AKI, participants had increased TKV, increased cortex/medulla T and reduced cortical perfusion compared with the expected ranges in healthy volunteers and people with CKD. TKV and T values decreased over time after AKI and returned to expected values in most but not all patients by 1 year. Cortical perfusion improved to a lesser extent and remained below the expected range in the majority of patients by 1-year post-AKI. BOLD R* data showed a non-significant trend to increase over time post-AKI.

Conclusions: We observed a substantial increase in TKV and T during AKI and a marked decrease in cortical perfusion. Despite biochemical recovery at 1-year post-AKI, MRI measures indicated persisting abnormalities in some patients. We propose that such patients may be more likely to have further AKI episodes or progress to CKD and further longitudinal studies are required to investigate this. .
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http://dx.doi.org/10.1093/ckj/sfaa221DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8323137PMC
August 2021

Developing an AKI Consensus Definition for Database Research: Findings From a Scoping Review and Expert Opinion Using a Delphi Process.

Am J Kidney Dis 2021 Jul 20. Epub 2021 Jul 20.

Renal Unit, Ninewells Hospital, Dundee, United Kingdom; Division of Population Health and Genomics, Medical Research Institute, University of Dundee, Dundee, United Kingdom. Electronic address:

Rationale & Objective: The KDIGO (Kidney Disease: Improving Global Outcomes) definition of acute kidney injury (AKI) is frequently used in studies to examine the epidemiology of AKI. This definition is variably interpreted and applied to routinely collected health care data. The aim of this study was to examine this variation and to achieve consensus in how AKI should be defined for research using routinely collected health care data.

Sources Of Evidence And Study Design: Scoping review via searching Medline and EMBASE for studies using health care data to examine AKI by using the KDIGO creatinine-based definition. An international panel of experts formed to participate in a modified Delphi process to attempt to generate consensus about how AKI should be defined when using routinely collected laboratory data.

Charting Methods And Analytical Approach: The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) extension for scoping reviews was followed. For the Delphi process, 2 rounds of questions were distributed via internet-based questionnaires to all participants with a prespecified cutoff of 75% agreement used to define consensus.

Results: The scoping review found 174 studies that met the inclusion criteria. The KDIGO definition was inconsistently applied, and the methods for application were poorly described. We found 58 (33%) of papers did not provide a definition of how the baseline creatinine value was determined, and only 34 (20%) defined recovery of kidney function. Of 55 invitees to the Delphi process, 35 respondents participated in round 1, and 25 participated in round 2. Some consensus was achieved in areas related to how to define the baseline creatinine value, which patients should be excluded from analysis of routinely collected laboratory data, and how persistent chronic kidney disease or nonrecovery of AKI should be defined.

Limitations: The Delphi panel members predominantly came from the United Kingdom, the United States, and Canada, and there were low response rates for some questions in round 1.

Conclusions: The current methods for defining AKI using routinely collected data are inconsistent and poorly described in the available literature. Experts could not achieve consensus for many aspects of defining AKI and describing its sequelae. The KDIGO guidelines should be extended to include a standardized definition for how AKI should be defined when using routinely collected data.
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http://dx.doi.org/10.1053/j.ajkd.2021.05.019DOI Listing
July 2021

An Analysis of Frequency of Continuous Blood Pressure Variation and Haemodynamic Responses during Haemodialysis.

Blood Purif 2021 Jul 22:1-15. Epub 2021 Jul 22.

Centre for Kidney Research and Innovation, Academic unit for Translational Medical Sciences, School of Medicine, University of Nottingham, Nottingham, United Kingdom.

Background: Higher beat-to-beat blood pressure (BP) variation during haemodialysis (HD) has been shown to be associated with elevated cardiac damage markers and white matter ischaemic changes in the brain suggesting relevance to end-organ perfusion. We aimed to characterize individual patterns of BP variation and associated haemodynamic responses to HD.

Methods: Fifty participants underwent continuous non-invasive haemodynamic monitoring during HD and BP variation were assessed using extrema point (EP) frequency analysis. Participants were divided into those with a greater proportion of low frequency (LF, n = 21) and high frequency (HF, n = 22) of BP variation. Clinical and haemodynamic data were compared between groups.

Results: Median EP frequencies for mean arterial pressure (MAP) of mid-week HD sessions were 0.54 Hz (interquartile range 0.18) and correlated with dialysis vintage (r = 0.32, p = 0.039), NT pro-BNP levels (r = 0.32, p = 0.038), and average real variability (ARV) of systolic BP (r = 0.33, p = 0.029), ARV of diastolic BP (r = 0.46, p = 0.002), and ARV of MAP (r = 0.57, p < 0.001). In the LF group, MAP positively correlated with cardiac power index (CPI) in each hour of dialysis, but not with total peripheral resistance index (TPRI). In contrast, in the HF group, MAP correlated with TPRI in each hour of dialysis but only with CPI in the first hour.

Conclusions: EP frequency analysis of continuous BP monitoring during dialysis allows assessment of BP variation and categorization of individuals into low- or high-frequency groups, which were characterized by different haemodynamic responses to dialysis. This may assist in improved individualization of dialysis therapy.
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http://dx.doi.org/10.1159/000516935DOI Listing
July 2021

Impact of malnutrition on health-related quality of life in persons receiving dialysis: a prospective study.

Br J Nutr 2021 Jul 5:1-24. Epub 2021 Jul 5.

Centre for Kidney Research and Innovation, Academic Unit for Translational Medical Sciences, School of Medicine, University of Nottingham, Royal Derby Hospital, Uttoxeter Rd, Derby, DE22 3NE, United Kingdom.

Health-related quality of life (HRQoL) is severely impaired in persons receiving dialysis. Malnutrition has been associated with some measures of poor HRQoL in cross-sectional analyses in dialysis populations, but no studies have assessed the impact of malnutrition and dietary intake on change in multiple measures of HRQoL over time. We investigated the most important determinants of poor HRQoL and the predictors of change in HRQoL over time using several measures of HRQoL. We enrolled 119 haemodialysis and 31 peritoneal dialysis patients in this prospective study. Nutritional assessments (Subjective Global Assessment [SGA], anthropometry and 24-hour dietary recalls) and HRQoL questionnaires (Short Form-36 [SF-36] mental [MCS] and physical component scores [PCS] and European QoL-5 Dimensions [EQ5D] health state [HSS] and visual analogue scores [VAS]) were performed at baseline, 6 and 12 months. Mean age was 64(14) years. Malnutrition was present in 37% of the population. At baseline, malnutrition assessed by SGA was the only factor independently (and negatively) associated with all four measures of HRQoL. No single factor was independently associated with decrease in all measures of HRQoL over 1 year. However, prevalence/development of malnutrition over one year was an independent predictor of 1-year decrease in EQ5D HSS and 1-year decrease in fat intake independently predicted the 1-year decline in SF-36 MCS and PCS, and EQ5D VAS. These findings strengthen the importance of monitoring for malnutrition and providing nutritional advice to all persons on dialysis. Future studies are needed to evaluate the impact of nutritional interventions on HRQoL and other long-term outcomes.
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http://dx.doi.org/10.1017/S000711452100249XDOI Listing
July 2021

Body mass index and chronic kidney disease outcomes after acute kidney injury: a prospective matched cohort study.

BMC Nephrol 2021 May 28;22(1):200. Epub 2021 May 28.

Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA.

Background: Acute kidney injury (AKI) and obesity are independent risk factors for chronic kidney disease (CKD). This study aimed to determine if obesity modifies risk for CKD outcomes after AKI.

Methods: This prospective multisite cohort study followed adult survivors after hospitalization, with or without AKI. The primary outcome was a combined CKD event of incident CKD, progression of CKD and kidney failure, examined using time-to-event Cox proportional hazards models, adjusted for diabetes status, age, pre-existing CKD, cardiovascular disease status and intensive care unit admission, and stratified by study center. Body mass index (BMI) was added as an interaction term to examine effect modification by body size.

Results: The cohort included 769 participants with AKI and 769 matched controls. After median follow-up of 4.3 years, among AKI survivors, the rate of the combined CKD outcome was 84.7 per1000-person-years with BMI ≥30 kg/m, 56.4 per 1000-person-years with BMI 25-29.9 kg/m, and 72.6 per 1000-person-years with BMI 20-24.9 kg/m. AKI was associated with a higher risk of combined CKD outcomes; adjusted-HR 2.43 (95%CI 1.87-3.16), with no evidence that this was modified by BMI (p for interaction = 0.3). After adjustment for competing risk of death, AKI remained associated with a higher risk of the combined CKD outcome (subdistribution-HR 2.27, 95%CI 1.76-2.92) and similarly, there was no detectable effect of BMI modifying this risk.

Conclusions: In this post-hospitalization cohort, we found no evidence for obesity modifying the association between AKI and development or progression of CKD.
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http://dx.doi.org/10.1186/s12882-021-02400-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8161937PMC
May 2021

Contrast-enhanced ultrasound assessed renal microvascular perfusion may predict postoperative renal complications following colorectal surgery.

Clin Exp Pharmacol Physiol 2021 07 1;48(7):971-977. Epub 2021 May 1.

Royal Derby Hospital, Derby, UK.

Colorectal surgery is associated with an above-average mortality rate of approximately 15%. During surgery, maintenance of vital organ perfusion is essential in order to reduce postoperative mortality and morbidity, with renal perfusion of particular importance. Oesophageal Doppler monitors (ODM) are commonly used to try and provide accurate measures of fluid depletion during surgery; however, it is unclear to what extent they reflect organ perfusion. In addition, it is not known whether macro- and/ or microvascular perfusion indices are associated with renal complications following colorectal surgery. Thirty-two participants scheduled for colorectal surgery had three measures of macro- and microvascular renal blood flow via contrast enhanced ultrasound (CEUS), and simultaneous measures of cardiac output indices via ODM: (i) pre-operatively; (ii) intra-operatively at the mid-point of operation, and (iii) after the conclusion of surgery. The Postoperative Morbidity Survey (POMS) was used to assess postoperative complications. Intra-operatively, there was a significant correlation between renal microvascular flow (RT) and renal macrovascular flow (TTI) (ρ = 0.52; p = 0.003). Intra-operative TTI, but not RT, was associated with cardiac index (ρ = -0.50; p=0.0003). Intra-operative RT predicted increases in renal complications (OR 1.46; 95% CI 1.03-2.09) with good discrimination (C-statistic, 0.85). Complications were not predicted by TTI or ODM-derived indices. There was no relationship between RT and TTI before or after surgery. ODM measures of haemodynamic status do not correlate with renal microvascular blood flow, and as such are likely not suitable to determine vital organ perfusion. Only CEUS-derived measures of microvascular perfusion were predictive of postoperative renal complications.
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http://dx.doi.org/10.1111/1440-1681.13501DOI Listing
July 2021

Randomized Controlled Trial Evidence of Cost-Effectiveness of a Multifaceted AKI Intervention Approach.

Kidney Int Rep 2021 Mar 16;6(3):636-644. Epub 2020 Dec 16.

Alira Health, Framingham, Massachusetts, USA.

Introduction: Acute kidney injury (AKI) is associated with increased health care utilization and higher costs. The Tackling AKI study was a multicenter, pragmatic, stepped-wedge cluster randomized trial that demonstrated a reduced hospital length of stay after implementation of a multifaceted AKI intervention (e-alerts, care bundle, and an education program). We tested whether this would result in cost savings.

Methods: A decision-analytic tree model from the payer perspective (National Health Service in the United Kingdom) was generated on which cost-effectiveness analyses were performed using a probabilistic sensitivity analysis, accounting only for direct medical costs. Clinical data from the Tackling AKI study were used as inputs and economic and utility data derived from relevant published literature.

Results: A total of 24,059 AKI episodes occurred during the study period, and in 18,887 admissions the patient was discharged alive. When all AKI stages were considered together, the cost per AKI admission was £5065 in the control arm and £4333 in the intervention arm, representing an incremental cost saving of £732 per admission with the intervention. Similar results were obtained when AKI stages were included as separate variables. Costs per quality-adjusted life year were £61,194 in the control group and £51,161 in the intervention group. At a willingness to pay threshold of £20,000 per quality-adjusted life year, the probability of the intervention being cost-effective compared with standard care was 90%.

Conclusion: An organizational level approach to improve standards of AKI care reduces the cost of hospital admissions and is cost effective within the National Health Service in the United Kingdom.
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http://dx.doi.org/10.1016/j.ekir.2020.12.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7938080PMC
March 2021

EDTAKI: A Nephrology and Public Policy Committee (NPPC) Platform Call for More European Involvement in AKI.

Nephrol Dial Transplant 2021 Feb 2. Epub 2021 Feb 2.

Department of Nephrology, Ambroise Paré University Hospital, APHP, Boulogne-Billancourt/Paris, and Centre for Research in Epidemiology and Population Health (CESP), Paris-Saclay University, Versailles Saint Quentin University, INSERM UMRS 1018, Team5 Villejuif, France.

Acute Kidney Injury (AKI) is an often neglected but crucial element of clinical nephrology. The aim of the Nephrology Public Policy Committee (NPPC) of the European Renal Association - European Dialysis and Transplant Association (ERA-EDTA) is to promote several key aspects of European nephrology. One of the targets proposed by NPPC was to advance European nephrology involvement in AKI. We undertook literature analyses to define the current position of European nephrology in the field of AKI compared to other regions, and about how different European countries compare to each other. It appeared that vis-à-vis countries with a comparable socio-economic status (the US, Australia, New Zealand, Canada), the European contribution was almost 50% lower. Within Europe, Central/Eastern Europe and countries with a lower gross domestic product (GDP) showed lower scientific output. Nephrologists contributed to less than half of the output. There was no trend for a change over the last decade. It is concluded that there is room to improve the contribution of European nephrology in the field of AKI. We propose a model on how to promote clinical collaboration on AKI across Europe, the creation of a pan-European nephrology network of interested units is proposed, to improve clinical outcomes, increase nephrologist involvement and awareness outside nephrology, and stimulate research on AKI in Europe. Accordingly, we also propose a list of research priorities and stress the need for more European funding of AKI research.
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http://dx.doi.org/10.1093/ndt/gfab018DOI Listing
February 2021

A narrative systematic review of randomised controlled trials that compare cannulation techniques for haemodialysis.

J Vasc Access 2021 Jan 10:1129729820983174. Epub 2021 Jan 10.

University Hospitals of Derby and Burton NHS Foundation Trust, Derby, UK.

Background: Cannulation of arteriovenous access for haemodialysis affects longevity of the access, associates with complications and affects patients' experiences of haemodialysis. Buttonhole and rope ladder techniques were developed to reduce complications. However, studies that compare these two techniques report disparate results. This systematic review performs an in-depth exploration of RCTs, with a specific focus on cannulation as a complex intervention.

Methods: A PICO question and protocol was developed as per PRISMA-P guidance and registered on PROSPERO (CRD42018094656 https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=112895). The systematic review included any RCT performed on adult patients with end-stage kidney disease undergoing cannulation of arteriovenous fistulae or grafts for in-centre haemodialysis, as performed by healthcare staff. Assessment of quality of RCTs and data extraction were performed by two co-authors independently. Data were extracted on the study design, intervention and comparator and outcomes, including patency, infection and patients' experiences.

Results: The literature search identified 241 records. Ten records met inclusion criteria, which described five different RCTs that compared buttonhole to either rope ladder or usual practice. Results were disparate, with patency and infection results varying. Pain Visual Analogue scores were the only measure used to capture patients' experiences and results were inconclusive. All RCTs had differences and limitations in study design that could explain the disparity in results.

Conclusion: Current evidence does not allow definitive conclusions as to whether buttonhole or rope ladder needling technique is superior. Future RCTs should describe interventions and comparators with adequate detail, embed process evaluation, use standardised outcome measures and build on feasibility studies to produce definitive results.
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http://dx.doi.org/10.1177/1129729820983174DOI Listing
January 2021

Application of the Lomb-Scargle Periodogram to InvestigateHeart Rate Variability during Haemodialysis.

J Healthc Eng 2020 8;2020:8862074. Epub 2020 Dec 8.

Centre for Kidney Research and Innovation, University of Nottingham, Derby, UK.

Short-term cardiovascular compensatory responses to perturbations in the circulatory system caused by haemodialysis can be investigated by the spectral analysis of heart rate variability, thus providing an important variable for categorising individual patients' response, leading to a more personalised treatment. This is typically accomplished by resampling the irregular heart rate to generate an equidistant time series prior to spectral analysis, but resampling can further distort the data series whose interpretation can already be compromised by the presence of artefacts. The Lomb-Scargle periodogram provides a more direct method of spectral analysis as this method is specifically designed for large, irregularly sampled, and noisy datasets such as those obtained in clinical settings. However, guidelines for preprocessing patient data have been established in combination with equidistant time-series methods and their validity when used in combination with the Lomb-Scargle approach is missing from literature. This paper examines the effect of common preprocessing methods on the Lomb-Scargle power spectral density estimate using both real and synthetic heart rate data and will show that many common techniques for identifying and editing suspect data points, particularly interpolation and replacement, will distort the resulting power spectrum potentially misleading clinical interpretations of the results. Other methods are proposed and evaluated for use with the Lomb-Scargle approach leading to the main finding that suspicious data points should be excluded rather than edited, and where required, denoising of the heart rate signal can be reliably accomplished by empirical mode decomposition. Some additional methods were found to be particularly helpful when used in conjunction with the Lomb-Scargle periodogram, such as the use of a false alarm probability metric to establish whether spectral estimates are valid and help automate the assessment of valid heart rate records, potentially leading to greater use of this powerful technique in a clinical setting.
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http://dx.doi.org/10.1155/2020/8862074DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7738214PMC
December 2020

A Feasibility Study of Non-Invasive Continuous Estimation of Brachial Pressure Derived From Arterial and Venous Lines During Dialysis.

IEEE J Transl Eng Health Med 2021 4;9:2700209. Epub 2020 Nov 4.

Centre for Kidney Research and InnovationUniversity of NottinghamNottinghamNG7 2RDU.K.

Intradialytic haemodynamic instability is a significant clinical problem, leading to end-organ ischaemia and contributing to morbidity and mortality in haemodialysis patients. Non-invasive continuous blood pressure monitoring is not currently part of routine practice but may aid detection and prevention of significant falls in blood pressure during dialysis. Brachial blood pressure is currently recorded intermittently during haemodialysis via a sphygmomanometer. Current methods of continuous non-invasive blood pressure monitoring tend to restrict movement, can be sensitive to external disturbances and patient movement, and can be uncomfortable for the wearer. Additionally, poor patient blood circulation can lead to unreliable measurements. In this feasibility study we performed an initial validation of a novel method and associated technology to continuously estimate blood pressure using pressure sensors in the extra-corporeal dialysis circuit, which does not require any direct contact with the person receiving dialysis treatment. The paper describes the development of the measurement system and subsequent patient feasibility study with concurrent measurement validation by physiological measurement device. Real-time physiological data is collected over the entire period of (typically 4-hour) dialysis treatment. We identify a quasi-linear mathematical function to describe the relationship between arterial line pressure and brachial artery BP, which is confirmed in a patient study. The results from this observational study suggest that it is feasible to derive a continuous measurement of brachial pressure from continuous measurements of arterial and venous line pressures via an empirically based and updated mathematical model. The methodology presented requires no interfacing to proprietary dialysis machine systems, no sensors to be attached to the patient directly, and is robust to patient movement during treatment and also to the effects of the cyclical pressure waveforms induced by the hemodialysis peristaltic blood pump. This represents a key enabling factor to the development of a practical continuous blood pressure monitoring device for dialysis patients.
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http://dx.doi.org/10.1109/JTEHM.2020.3035988DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7665243PMC
November 2020

Application of dynamic contrast enhanced ultrasound in the assessment of kidney diseases.

Curr Opin Nephrol Hypertens 2021 01;30(1):138-143

Division of Medical Sciences and Graduate Entry Medicine, MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham Biomedical Research Centre, University of Nottingham, Royal Derby Hospital Centre.

Purpose Of Review: Many forms of acute and chronic disease are linked to changes in renal blood flow, perfusion, vascular density and hypoxia, but there are no readily available methods to assess these parameters in clinical practice. Dynamic contrast enhanced ultrasound (DCE-US) is a method that provides quantitative assessments of organ perfusion without ionising radiation or risk of nephrotoxicity. It can be performed at the bedside and is suitable for repeated measurements. The purpose of this review is to provide updates from recent publications on the utility of DCE-US in the diagnosis or assessment of renal disease, excluding the evaluation of benign or malignant renal masses.

Recent Findings: DCE-US has been applied in clinical studies of acute kidney injury (AKI), renal transplantation, chronic kidney disease (CKD), diabetic kidney disease and to determine acute effects of pharmacological agents on renal haemodynamics. DCE-US can detect changes in renal perfusion across these clinical scenarios and can differentiate healthy controls from those with CKD. In sepsis, reduced DCE-US measures of perfusion may indicate those at increased risk of developing AKI, but this requires confirmation in larger studies as there can be wide individual variation in perfusion measures in acutely unwell patients. Recent studies in transplantation have not provided robust evidence to show that DCE-US can differentiate between different causes of graft dysfunction, although it may show more promise as a prognostic indicator of graft function 1 year after transplant. DCE-US can detect acute haemodynamic changes in response to medication that correlate with changes in renal plasma flow as measured by para-aminohippurate clearance.

Summary: DCE-US shows promise and has a number of advantages that make it suitable for the assessment of patients with various forms of kidney disease. However, further research is required to evidence its reproducibility and utility before clinical use can be advocated.
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http://dx.doi.org/10.1097/MNH.0000000000000664DOI Listing
January 2021

Dialysis-Induced Cardiovascular and Multiorgan Morbidity.

Kidney Int Rep 2020 Nov 9;5(11):1856-1869. Epub 2020 Sep 9.

Renal Research Institute, New York, NY, USA.

Hemodialysis has saved many lives, albeit with significant residual mortality. Although poor outcomes may reflect advanced age and comorbid conditions, hemodialysis may harm patients, contributing to morbidity and perhaps mortality. Systemic circulatory "stress" resulting from hemodialysis treatment schedule may act as a disease modifier, resulting in a multiorgan injury superimposed on preexistent comorbidities. New functional intradialytic imaging (i.e., echocardiography, cardiac magnetic resonance imaging [MRI]) and kinetic of specific cardiac biomarkers (i.e., Troponin I) have clearly documented this additional source of end-organ damage. In this context, several factors resulting from patient-hemodialysis interaction and/or patient management have been identified. Intradialytic hypovolemia, hypotensive episodes, hypoxemia, solutes, and electrolyte fluxes as well as cardiac arrhythmias are among the contributing factors to systemic circulatory stress that are induced by hemodialysis. Additionally, these factors contribute to patients' symptom burden, impair cognitive function, and finally have a negative impact on patients' perception and quality of life. In this review, we summarize the adverse systemic effects of current intermittent hemodialysis therapy, their pathophysiologic consequences, review the evidence for interventions that are cardioprotective, and explore new approaches that may further reduce the systemic burden of hemodialysis. These include improved biocompatible materials, smart dialysis machines that automatically may control the fluxes of solutes and electrolytes, volume and hemodynamic control, health trackers, and potentially disruptive technologies facilitating a more personalized medicine approach.
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http://dx.doi.org/10.1016/j.ekir.2020.08.031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7609914PMC
November 2020

Acute kidney injury associated with COVID-19: A retrospective cohort study.

PLoS Med 2020 10 30;17(10):e1003406. Epub 2020 Oct 30.

Department of Nephrology, University Hospitals of Derby and Burton, Royal Derby Hospital, Derby, United Kingdom.

Background: Initial reports indicate a high incidence of acute kidney injury (AKI) in Coronavirus Disease 2019 (COVID-19), but more data are required to clarify if COVID-19 is an independent risk factor for AKI and how COVID-19-associated AKI may differ from AKI due to other causes. We therefore sought to study the relationship between COVID-19, AKI, and outcomes in a retrospective cohort of patients admitted to 2 acute hospitals in Derby, United Kingdom.

Methods And Findings: We extracted electronic data from 4,759 hospitalised patients who were tested for COVID-19 between 5 March 2020 and 12 May 2020. The data were linked to electronic patient records and laboratory information management systems. The primary outcome was AKI, and secondary outcomes included in-hospital mortality, need for ventilatory support, intensive care unit (ICU) admission, and length of stay. As compared to the COVID-19-negative group (n = 3,374), COVID-19 patients (n = 1,161) were older (72.1 ± 16.1 versus 65.3 ± 20.4 years, p < 0.001), had a greater proportion of men (56.6% versus 44.9%, p < 0.001), greater proportion of Asian ethnicity (8.3% versus 4.0%, p < 0.001), and lower proportion of white ethnicity (75.5% versus 82.5%, p < 0.001). AKI developed in 304 (26.2%) COVID-19-positive patients (COVID-19 AKI) and 420 (12.4%) COVID-19-negative patients (AKI controls). COVID-19 patients aged 65 to 84 years (odds ratio [OR] 1.67, 95% confidence interval [CI] 1.11 to 2.50), needing mechanical ventilation (OR 8.74, 95% CI 5.27 to 14.77), having congestive cardiac failure (OR 1.72, 95% CI 1.18 to 2.50), chronic liver disease (OR 3.43, 95% CI 1.17 to 10.00), and chronic kidney disease (CKD) (OR 2.81, 95% CI 1.97 to 4.01) had higher odds for developing AKI. Mortality was higher in COVID-19 AKI versus COVID-19 patients without AKI (60.5% versus 27.4%, p < 0.001), and AKI was an independent predictor of mortality (OR 3.27, 95% CI 2.39 to 4.48). Compared with AKI controls, COVID-19 AKI was observed in a higher proportion of men (58.9% versus 51%, p = 0.04) and lower proportion with white ethnicity (74.7% versus 86.9%, p = 0.003); was more frequently associated with cerebrovascular disease (11.8% versus 6.0%, p = 0.006), chronic lung disease (28.0% versus 19.3%, p = 0.007), diabetes (24.7% versus 17.9%, p = 0.03), and CKD (34.2% versus 20.0%, p < 0.001); and was more likely to be hospital acquired (61.2% versus 46.4%, p < 0.001). Mortality was higher in the COVID-19 AKI as compared to the control AKI group (60.5% versus 27.6%, p < 0.001). In multivariable analysis, AKI patients aged 65 to 84 years, (OR 3.08, 95% CI 1.77 to 5.35) and ≥85 years of age (OR 3.54, 95% CI 1.87 to 6.70), peak AKI stage 2 (OR 1.74, 95% CI 1.05 to 2.90), AKI stage 3 (OR 2.01, 95% CI 1.13 to 3.57), and COVID-19 (OR 3.80, 95% CI 2.62 to 5.51) had higher odds of death. Limitations of the study include retrospective design, lack of urinalysis data, and low ethnic diversity of the region.

Conclusions: We observed a high incidence of AKI in patients with COVID-19 that was associated with a 3-fold higher odds of death than COVID-19 without AKI and a 4-fold higher odds of death than AKI due to other causes. These data indicate that patients with COVID-19 should be monitored for the development of AKI and measures taken to prevent this.

Trial Registration: ClinicalTrials.gov NCT04407156.
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http://dx.doi.org/10.1371/journal.pmed.1003406DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7598516PMC
October 2020

New imaging techniques in AKI.

Curr Opin Crit Care 2020 12;26(6):543-548

Department of Anesthesiology and Intensive Care, Paris-Saclay University, Bicêtre Hospital, Assistance Publique Hôpitaux de Paris (AP-HP), Le Kremlin-Bicêtre, France.

Purpose Of Review: Acute kidney injury (AKI) is a common complication in critically ill patients. Understanding the pathophysiology of AKI is essential to guide patient management. Imaging techniques that inform the pathogenesis of AKI in critically ill patients are urgently needed, in both research and ultimately clinical settings. Renal contrast-enhanced ultrasonography (CEUS) and multiparametric MRI appear to be the most promising imaging techniques for exploring the pathophysiological mechanisms involved in AKI.

Recent Findings: CEUS and MRI can be used to noninvasively and safely evaluate renal macrocirculation and microcirculation and oxygenation in critical ill patients. These techniques show that a decrease in renal blood flow, particularly cortical blood flow, may be observed in septic AKI and may contribute to its development. MRI may be a valuable method to quantify long-term renal damage after AKI that cannot currently be detected using standard clinical approaches.

Summary: CEUS and multiparametric renal MRI are promising imaging techniques but more evidence is needed to show how they can first be more widely used in a research setting to test key hypotheses about the pathophysiology and recovery of AKI, and then ultimately be adopted in clinical practice to guide patient management.
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http://dx.doi.org/10.1097/MCC.0000000000000768DOI Listing
December 2020

Correction to: Phase-contrast magnetic resonance imaging to assess renal perfusion: a systematic review and statement paper.

MAGMA 2020 10;33(5):747

Department of Biomedical Engineering, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy.

The article Phase‑contrast magnetic resonance imaging to assess renal perfusion: a systematic review and statement paper, written by Giulia Villa, Steffen Ringgaard, Ingo Hermann, Rebecca Noble, Paolo Brambilla, Dinah S. Khatir, Frank G. Zöllner, Susan T. Francis, Nicholas M. Selby, Andrea Remuzzi and Anna Caroli, was originally published electronically on the publisher's internet portal on 17 August 2019 without open access.
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http://dx.doi.org/10.1007/s10334-020-00849-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7502060PMC
October 2020

Covid-19 and acute kidney injury in hospital: summary of NICE guidelines.

BMJ 2020 May 26;369:m1963. Epub 2020 May 26.

Department of Renal Medicine, Royal Derby Hospital, Derby, UK.

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http://dx.doi.org/10.1136/bmj.m1963DOI Listing
May 2020

Factors Associated With Change in Skin Autofluorescence, a Measure of Advanced Glycation End Products, in Persons Receiving Dialysis.

Kidney Int Rep 2020 May 15;5(5):654-662. Epub 2020 Feb 15.

Centre for Kidney Research and Innovation, Division of Medical Sciences and Graduate Entry Medicine, School of Medicine, University of Nottingham, UK.

Introduction: An increase over time in skin autofluorescence (SAF), a measure of accumulation of advanced glycation end products (AGE), predicts higher mortality on hemodialysis (HD). However, evidence is lacking regarding factors that contribute to changes in SAF over time in populations on dialysis. We investigated the rate of change in SAF over 1 year and the factors associated with these changes.

Methods: We enrolled 109 patients on HD and 28 on peritoneal dialysis in a prospective study. SAF was measured at baseline, 3, 6, 9, and 12 months. Rate of change in SAF was calculated using the SLOPE function in Microsoft Excel (Microsoft, Redmond, WA). Participants were then grouped into those with stable SAF or increasing SAF. Dietary AGE intake and nutritional assessments were performed at baseline, 6, and 12 months.

Results: The mean SAF trend observed was an increase of 0.30 ± 0.63 arbitrary units (AU) per year, but this varied from a decrease of 0.15 ± 0.44 to an increase of 0.76 ± 0.42 AU per year in stable and increasing SAF groups, respectively. Increasing SAF was more common in participants who developed malnutrition during the observation period, whereas those who became well-nourished were more likely to have stable SAF (8 [80%] vs. 14 [42%]; 0.02). Development/prevalence of malnutrition over 1 year, HD as first dialysis modality, and current smoking were independent predictors of increasing SAF.

Conclusion: SAF increases over time in most persons on dialysis. Independent determinants of increasing SAF were development/prevalence of malnutrition, HD as first dialysis modality, and current smoking. Strategies to reduce/prevent the rise in SAF, including prevention/correction of malnutrition, should be investigated in prospective studies.
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http://dx.doi.org/10.1016/j.ekir.2020.02.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7210606PMC
May 2020

Skin autofluorescence and malnutrition as predictors of mortality in persons receiving dialysis: a prospective cohort study.

J Hum Nutr Diet 2020 12 8;33(6):852-861. Epub 2020 May 8.

Division of Medical Sciences and Graduate Entry Medicine, School of Medicine, Centre for Kidney Research and Innovation, University of Nottingham, Royal Derby Hospital, Derby, UK.

Background: Skin autofluorescence (SAF), which is a measure of accumulation of advanced glycation end-products (AGE), and malnutrition are each associated with higher mortality in dialysis populations, although no studies have investigated these potentially related associations together. We simultaneously assessed SAF and malnutrition as risk factors for mortality in persons receiving dialysis.

Methods: SAF was measured in 120 haemodialysis and 31 peritoneal dialysis patients using an AGE Reader (DiagnOptics, Groningen, The Netherlands). Dietary AGE, energy, protein and fat intake, handgrip strength, anthropometry, biochemistry and Subjective Global Assessment were also evaluated. Time to event was days from baseline to death, kidney transplantation or 30 September 2018.

Results: Median observation time was 576 days, during which 33 (21.9%) patients died. Those who died had higher baseline SAF levels [3.8 ± 1.0 versus 3.3 ± 0.8 arbitrary units (AU); P = 0.001] and were more likely to be malnourished (58% versus 31%; P = 0.006). Malnourished persons who died had higher SAF values than those who died but were well-nourished (4.2 ± 1.1 versus 3.3 ± 0.7 AU; P = 0.007). Survival was significantly better in participants with baseline SAF below the median and in those well-nourished than those with baseline SAF above the median and in those malnourished, respectively. Multivariable analysis identified SAF [hazards ratio (HR) = 1.44; 95% confidence interval (CI) = 1.05-1.97; P = 0.02], malnutrition (HR = 2.35; 95% CI = 1.16-4.78; P = 0.02) and chronological age (HR = 1.60; 95% CI = 1.10-2.33; P = 0.01) as independent predictors of mortality.

Conclusions: Although higher SAF and malnutrition are potentially inter-related, they were both independently associated with increased mortality in this population. Interventions to improve outcomes by reducing SAF through correction of malnutrition or dietary AGE restriction require testing in prospective studies.
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http://dx.doi.org/10.1111/jhn.12764DOI Listing
December 2020

An updated overview of diabetic nephropathy: Diagnosis, prognosis, treatment goals and latest guidelines.

Diabetes Obes Metab 2020 04;22 Suppl 1:3-15

Centre for Kidney Research and Innovation, University of Nottingham, Nottingham, UK.

Diabetic nephropathy (DN) is a major healthcare challenge. It occurs in up to 50% of those living with diabetes, is a major cause of end-stage kidney disease (ESKD) that requires treatment with dialysis or renal transplantation, and is associated with significantly increased cardiovascular morbidity and mortality. DN is a clinical syndrome characterized by persistent albuminuria and a progressive decline in renal function, but it is increasingly recognized that the presentation and clinical course of kidney disease in diabetes is heterogeneous. The term diabetic kidney disease (DKD) is now commonly used to encompass the spectrum of people with diabetes who have either albuminuria or reductions in renal function. In this article, the clinical presentation and approach to diagnosis of DKD will be discussed, as will its prognosis. The general principles of management of DKD will also be reviewed with reference to current international guidelines.
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http://dx.doi.org/10.1111/dom.14007DOI Listing
April 2020

A Systematic Review of the Acute Effects of Hemodialysis on Skeletal Muscle Perfusion, Metabolism, and Function.

Kidney Int Rep 2020 Mar 30;5(3):307-317. Epub 2019 Dec 30.

Centre for Kidney Research and Innovation, School of Medicine, University of Nottingham, Derby, UK.

Introduction: The underlying mechanisms of skeletal muscle wasting in hemodialysis patients are complex. We performed a systematic review to summarize evidence on whether hemodialysis has acute effects on skeletal muscle perfusion, metabolism, and function.

Methods: The protocol was registered on PROSPERO (Registration number CRD42018103682). A systematic search was performed in MEDLINE, PubMed, Cochrane, Embase, Scopus, and Web of Science. Citation, reference list, and gray literature searches were also performed. Studies were selected in 2 stages: title and abstract review, then full-text review.

Results: A total of 65 full-text articles were reviewed, and 14 studies were eligible for inclusion. No studies were identified that assessed muscle perfusion during dialysis. Two studies used near-infrared spectroscopy to indirectly measure skeletal muscle oxygen consumption, which increased during dialysis in 1 study but only in patients with diabetes in the second. Metabolism was examined in 9 studies. A number of acute metabolic changes were reported (e.g., caspase-3 activity, polyubiquitin, and interleukin-6 protein increased in response to hemodialysis) as was a net negative protein balance over the dialysis session. Three studies examining muscle function did not produce consistent findings.

Conclusion: Gaps remain in understanding the acute effects of hemodialysis on skeletal muscle, particularly for changes in perfusion and function, although there does appear to be an acute effect on muscle metabolism.
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http://dx.doi.org/10.1016/j.ekir.2019.12.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7056853PMC
March 2020

Danger in the jungle: sensible care to reduce avoidable acute kidney injury in hospitalized children.

Kidney Int 2020 03;97(3):458-460

Department of Critical Care Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada. Electronic address:

When children require hospital admission, many receive medications with nephrotoxic potential. As such, this can translate into an increased risk of acute kidney injury. In this context, acute kidney injury is hospital acquired, often iatrogenic, and portends risk of adverse outcomes. The Nephrotoxic Injury Negated by Just-in-Time Action study implemented a multicenter hospital-wide quality improvement initiative to detect and reduce nephrotoxin exposure in children aimed at decreasing the rates of potentially avoidable acute kidney injury. This commentary explores the findings and implications of the Nephrotoxic Injury Negated by Just-in-Time Action study.
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http://dx.doi.org/10.1016/j.kint.2019.11.020DOI Listing
March 2020

Long-Term Outcomes in Patients with Acute Kidney Injury.

Clin J Am Soc Nephrol 2020 03 19;15(3):423-429. Epub 2020 Feb 19.

Centre for Kidney Research and Innovation, Division of Medical Sciences and Graduate Entry Medicine, School of Medicine, University of Nottingham, Nottingham, United Kingdom; and

The long-term sequelae of AKI have received increasing attention so that its associations with a number of adverse outcomes, including higher mortality and development of CKD, are now widely appreciated. These associations take on particular importance when considering the high incidence of AKI, with a lack of proven interventions and uncertainties around optimal care provision meaning that the long-term sequelae of AKI present a major unmet clinical need. In this review, we examine the published data that inform our current understanding of long-term outcomes following AKI and discuss potential knowledge gaps, covering long-term mortality, CKD, progression to ESKD, proteinuria, cardiovascular events, recurrent AKI, and hospital readmission.
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http://dx.doi.org/10.2215/CJN.10410919DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7057296PMC
March 2020

Impact of Dietetic Intervention on Skin Autofluorescence and Nutritional Status in Persons Receiving Dialysis: A Proof of Principle Study.

J Ren Nutr 2020 11 7;30(6):540-547. Epub 2020 Feb 7.

Division of Medical Sciences and Graduate Entry Medicine, Centre for Kidney Research and Innovation, School of Medicine, University of Nottingham, Nottingham, United Kingdom; Department of Renal Medicine, University Hospitals of Derby and Burton NHS Foundation Trust, Royal Derby Hospital, Derby, United Kingdom.

Objective: Advanced glycation end-products (AGEs) are uremic toxins that result from oxidative stress and food consumption. It has been reported that markers of malnutrition are more important determinants of increased skin autofluorescence (SAF), a measure of AGE accumulation and risk factor for mortality, than high dietary AGE intake in a hemodialysis (HD) population, suggesting that correcting malnutrition may decrease SAF.

Design And Methods: We investigated this hypothesis in a single-center, nonrandomized proof-of-principle study. We enrolled 27 patients on HD and one on peritoneal dialysis with malnutrition who received individualized nutritional advice and support over 6 months. SAF was measured at baseline, 3 months, and 6 months. Dietary intake and nutritional status were assessed at baseline and 6 months. Results were compared with a control group of malnourished patients on dialysis (n = 41 HD and 8 peritoneal dialysis) from a previous observational study.

Results: The intervention group showed a significant increase in dietary intake, including AGEs, Subjective Global Assessment score, and serum albumin, while SAF levels remained stable for over 6 months (3.8 ± 0.7 arbitrary units [AU] vs. 3.7 ± 0.7 AU; P = .3). Conversely, in the control group, SAF increased significantly during the observation period (3.5 ± 0.9 AU vs. 3.8 ± 1.2 AU; P = .03) during which there was no improvement in nutritional intake and other markers of nutrition, although dietary AGE intake and Subjective Global Assessment score did increase.

Conclusion: Dietetic support was associated with stable SAF levels in this proof-of-principal study despite an increase in dietary AGE intake, suggesting that interventions to improve nutrition may be important in preventing the rise in SAF observed in malnourished dialysis populations. Further long-term studies are needed to test this hypothesis and evaluate the impact on survival.
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http://dx.doi.org/10.1053/j.jrn.2019.12.006DOI Listing
November 2020

The Janus faces of bicarbonate therapy in the ICU: not sure!

Intensive Care Med 2020 03 9;46(3):522-524. Epub 2019 Dec 9.

Centre for Kidney Research and Innovation, School of Medicine, University of Nottingham, Nottingham, UK.

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http://dx.doi.org/10.1007/s00134-019-05885-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7223965PMC
March 2020

Barriers and enablers to the implementation of a complex quality improvement intervention for acute kidney injury: A qualitative evaluation of stakeholder perceptions of the Tackling AKI study.

PLoS One 2019 20;14(9):e0222444. Epub 2019 Sep 20.

Department of Renal Medicine, Derby Teaching Hospitals NHS Foundation Trust, Derby, United Kingdom.

Background: Acute kidney injury in hospital patients is common and associated with reduced survival and higher healthcare costs. The Tackling Acute Kidney Injury (TAKI) quality improvement project aimed to reduce mortality rates in patients with acute kidney injury by implementing a multicomponent intervention comprising of an electronic alert, care bundle and education in five UK hospitals across a variety of wards. A parallel developmental evaluation using a case study approach was conducted to provide the implementation teams with insights into factors that might impact intervention implementation and fidelity. The qualitative element of the evaluation will be reported.

Methods: 29 semi-structured interviews with implementation teams across the five hospitals were carried out to identify perceived barriers and enablers to implementation. Interviews were taped and transcribed verbatim and Framework analysis was conducted.

Results: Interviews generated four 'barriers and enablers' to implementation themes: i) practical/contextual factors, ii) skills and make-up of the TAKI implementation team, iii) design, development and implementation approach, iv) staff knowledge, attitudes, behaviours and support. Enablers included availability of specialist teams (e.g. educational teams), multi-disciplinary implementation teams with strong leadership, team-based package completion and proactive staff. Barriers were frequently the converse of facilitators.

Conclusions: Despite diversity of sites, a range of common local factors-contextual, intervention-based and individual-were identified as potential barriers and enablers to fidelity, including intervention structure/design and process of/approach to implementation. Future efforts should focus on early identification and management of barriers and tailored optimisation of known enablers such as leadership and multidisciplinary teams to encourage buy-in. Improved measures of real-time intervention and implementation fidelity would further assist local teams to target their support during such quality improvement initiatives.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0222444PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6754144PMC
March 2020

Peritoneal Ultrafiltration for Heart Failure: Lessons from a Randomized Controlled Trial.

Perit Dial Int 2019 Sep-Oct;39(5):486-489

University Hospitals of Derby and Burton, Derby, UK.

Peritoneal ultrafiltration (PuF) has been employed for severe heart failure (HF), but evidence for its benefit is lacking. The Peritoneal Dialysis for Heart Failure (PDHF) study was a multicenter prospective randomized controlled trial which aimed to investigate this issue. The trial stopped early due to inadequate recruitment. We describe methods, trial activity, and lessons learned.The trial aimed to recruit 130 participants with severe diuretic-resistant HF (New York Heart Association [NYHA] 3/4) and chronic kidney disease (CKD) stage 3/4 on optimal medical treatment for ≥ 4 weeks from 6 UK centers. Participants were randomized to either continuation of conventional HF treatment or to additionally receiving PuF (1 overnight exchange using Icodextrin dialysate). Primary outcome was change in 6-minute walk test (6MWT) between baseline and 28 weeks (end of trial). Secondary outcomes were changes in patient reported quality of life as assessed by the Kansas City Cardiomyopathy Questionnaire, short form 36 (SF 36) health survey results, hospitalization, and mortality.Over a 2-year period, 290 patients were screened from which only 20 met inclusion criteria and 10 were recruited. Reasons for ineligibility were fluctuating estimated glomerular filtration rate (eGFR), suboptimal HF treatment, frailty, and patients being too unwell for randomization. Barriers to recruitment included patient frailty, with some participants considered only when they were at end of life, unwillingness to engage in an invasive therapy, and suboptimal coordination between cardiology and renal services. This is a challenging patient group in which to perform research, and lessons learned from the peritoneal dialysis (PD)-HF trial will be helpful in the planning of future studies in this area.
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http://dx.doi.org/10.3747/pdi.2018.00272DOI Listing
August 2020

Phase-contrast magnetic resonance imaging to assess renal perfusion: a systematic review and statement paper.

MAGMA 2020 Feb 17;33(1):3-21. Epub 2019 Aug 17.

Department of Biomedical Engineering, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy.

Objective: Phase-contrast magnetic resonance imaging (PC-MRI) is a non-invasive method used to compute blood flow velocity and volume. This systematic review aims to discuss the current status of renal PC-MRI and provide practical recommendations which could inform future clinical studies and its adoption in clinical practice.

Methodology: A comprehensive search of all the PC-MRI studies in human healthy subjects or patients related to the kidneys was performed.

Results: A total of 39 studies were included in which PC-MRI was used to measure renal blood flow (RBF) alongside other derivative hemodynamic parameters. PC-MRI generally showed good correlation with gold standard methods of RBF measurement, both in vitro and in vivo, and good reproducibility. Despite PC-MRI not being routinely used in clinical practice, there are several clinical studies showing its potential to support diagnosis and monitoring of renal diseases, in particular renovascular disease, chronic kidney disease and autosomal dominant polycystic kidney disease.

Discussion: Renal PC-MRI shows promise as a non-invasive technique to reliably measure RBF, both in healthy volunteers and in patients with renal disease. Future multicentric studies are needed to provide definitive normative ranges and to demonstrate the clinical potential of PC-MRI, likely as part of a multi-parametric renal MRI protocol.
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http://dx.doi.org/10.1007/s10334-019-00772-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7210220PMC
February 2020

Evaluating a process of academic detailing in primary care: an educational programme for acute kidney injury.

BMC Med Educ 2019 Jul 9;19(1):253. Epub 2019 Jul 9.

Department of Renal Medicine, Royal Derby Hospital, University Hospitals of Derby and Burton NHS Foundation Trust, Uttoxeter Road, Derby, DE22 3NE, UK.

Background: Primary care has a significant role in AKI management: two-thirds of AKI originates in the community. Through academic detailing (an evidence-based educational approach) we aimed to implement and measure the effect of a primary care-based education programme based around academic detailing and peer-reviewed audit.

Methods: The education programme took place across a large clinical commissioning group (CCG) consisting of 55 primary care practices. All 55 practices participated in large group teaching sessions, 25 practices participated in academic detailing and 28 of the remaining 30 practices performed internal AKI audit. Over a 12 month period, an educational programme was delivered consisting of large group teaching sessions followed by either academic detailing sessions or self-directed AKI audit activity. Academic detailing sessions consisted of a short presentation by a consultant nephrologist followed by discussion of cases. Qualitative feedback was collected from all participants at peer review sessions. Web-based, CCG-wide questionnaires assessed baseline and post-intervention knowledge levels.

Results: Nine hundred ninety-six individuals completed the questionnaires (556 at baseline, 440 at 1 yr., 288 participated in both). Exposure to AKI teaching, self-reported awareness and confidence levels were higher in the second questionnaire. There was a significant increase in the percentage of correct answers before and after the intervention (55.6 ± 21% versus 87.5 ± 20%, p < 0.001). Improvements were also seen in practices that did not participate in academic detailing. 92.9% of participants in the academic detailing sessions ranked their usefulness as high, but half of participants expressed some anxiety about discussion of cases in front of peers.

Conclusion: Primary care education can improve knowledge and awareness of AKI. Small group teaching with involvement of a nephrologist was popular, although there were mixed responses to group discussion of real cases. Academic detailing did not appear more effective than other educational formats.
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http://dx.doi.org/10.1186/s12909-019-1659-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6617939PMC
July 2019

Quantitative assessment of renal structural and functional changes in chronic kidney disease using multi-parametric magnetic resonance imaging.

Nephrol Dial Transplant 2020 06;35(6):955-964

Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK.

Background: Multi-parametric magnetic resonance imaging (MRI) provides the potential for a more comprehensive non-invasive assessment of organ structure and function than individual MRI measures, but has not previously been comprehensively evaluated in chronic kidney disease (CKD).

Methods: We performed multi-parametric renal MRI in persons with CKD (n = 22, 61 ± 24 years) who had a renal biopsy and measured glomerular filtration rate (mGFR), and matched healthy volunteers (HV) (n = 22, 61 ± 25 years). Longitudinal relaxation time (T1), diffusion-weighted imaging, renal blood flow (phase contrast MRI), cortical perfusion (arterial spin labelling) and blood-oxygen-level-dependent relaxation rate (R2*) were evaluated.

Results: MRI evidenced excellent reproducibility in CKD (coefficient of variation <10%). Significant differences between CKD and HVs included cortical and corticomedullary difference (CMD) in T1, cortical and medullary apparent diffusion coefficient (ADC), renal artery blood flow and cortical perfusion. MRI measures correlated with kidney function in a combined CKD and HV analysis: estimated GFR correlated with cortical T1 (r = -0.68), T1 CMD (r = -0.62), cortical (r = 0.54) and medullary ADC (r = 0.49), renal artery flow (r = 0.78) and cortical perfusion (r = 0.81); log urine protein to creatinine ratio (UPCR) correlated with cortical T1 (r = 0.61), T1 CMD (r = 0.61), cortical (r = -0.45) and medullary ADC (r = -0.49), renal artery flow (r = -0.72) and cortical perfusion (r = -0.58). MRI measures (cortical T1 and ADC, T1 and ADC CMD, cortical perfusion) differed between low/high interstitial fibrosis groups at 30-40% fibrosis threshold.

Conclusion: Comprehensive multi-parametric MRI is reproducible and correlates well with available measures of renal function and pathology. Larger longitudinal studies are warranted to evaluate its potential to stratify prognosis and response to therapy in CKD.
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http://dx.doi.org/10.1093/ndt/gfz129DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7282828PMC
June 2020
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