Background & aims: Hospitalised older adults are vulnerable to dehydration. However, the prevalence of hyperosmolar dehydration (HD) and its impact on outcome is unknown. Serum osmolality is not measured routinely but osmolarity, a validated alternative, can be calculated using routinely measured serum biochemistry. This study aimed to use calculated osmolarity to measure the prevalence of HD (serum osmolarity >300 mOsm/l) and assess its impact on acute kidney injury (AKI) and outcome in hospitalised older adults. Methods: This retrospective cohort study used data from a UK teaching hospital retrieved from the electronic database relating to all medical emergency admissions of patients aged >= 65 years admitted between 1st May 2011 and 31st October 2013. Using these data, Charlson comorbidity index (CCI), National Early Warning Score (NEWS), length of hospital stay (LOS) and mortality were determined. Osmolarity was calculated using the equation of Krahn and Khajuria. Results: A total of 6632 patients were identified; 27% had HD, 39% of whom had AKI. HD was associated with a median (Q1, Q3) LOS of 5 (1, 12) days compared with 3 (1, 9) days in the euhydrated group, P < 0.001. Adjusted Cox-regression analysis demonstrated that patients with HD were four-times more likely to develop AKI 12-24 h after admission [Hazards Ratio (95% Confidence Interval) 4.5 (3.5-5.6), P < 0.001], and had 60% greater 30-day mortality [1.6 (1.4-1.9), P < 0.001], compared with those who were euhydrated. Conclusion: HD is common in hospitalised older adults and is associated with increased LOS, risk of AKI and mortality. Further work is required to assess the validity of osmolality or osmolarity as an early predictor of AKI and the impact of HD on outcome prospectively. (C) 2019 The Author(s). Published by Elsevier Ltd.

Background Acute kidney injury (AKI) is commonly defined using the KDIGO system, which includes criteria based on reduced urine output (UO). There is no consensus on whether UO should be measured using consecutive hourly readings or mean output. This makes KDIGO UO definition and staging of AKI vulnerable to inconsistency which has implications both for research and clinical practice. The objective of this study was to investigate whether the way in which UO is defined affects incidence and staging of AKI. Methods We conducted a retrospective analysis of two single centre observational studies investigating (i) patients undergoing cardiac surgery and (ii) patients admitted to general intensive care units (ICU). AKI was identified using KDIGO serum creatinine (SCr) criteria and two methods of UO (UOcons: UO meeting KDIGO criteria in each consecutive hour; UOmean: mean hourly UO meeting KDIGO criteria). Results Data from 151 CICU and 150 ICU admissions were analysed. Incidence of AKI using SCr alone was 23.8% in CICU and 32% in ICU. Incidence increased in both groups when UO was considered, with inclusion of UOmean more than doubling reported incidence of AKI (CICU: UOcons 39.7%, UOmean 72.8%; ICU: UOcons 51.3%, UOmean 69.3%). In both groups UOcons led to a larger increase in KDIGO stage 1 but UOmean increased the incidence of KDIGO stage 2. Conclusions We demonstrate a serious lack of clarity in the internationally accepted AKI definition leading to significant variability in reporting of AKI incidence.

Introduction: Malnutrition is common in patients with acute kidney injury (AKI), particularly in those requiring renal replacement therapy (RRT). Use of RRT removes metabolic waste products and toxins, but it will inevitably also remove useful molecules such as micronutrients, which might aggravate malnutrition. The RRT modalities vary in mechanism of solute removal; for example, intermittent hemodialysis (IHD) uses diffusion, continuous veno-venous hemofiltration (CVVH) uses convection, and sustained low-efficiency diafiltration (SLEDf) uses a combination of these. Methods: We assessed micronutrient and amino acid losses in 3 different RRT modalities in patients with AKI (IHD, n = 27; SLEDf, n = 12; CVVH, n = 21) after correction for dialysis dose and plasma concentrations. Results: Total losses were affected by modality; generally CVVH >> SLEDf > IHD (e.g., amino acid loss was 18.69 +/- 3.04, 8.21 +/- 4.07, and 5.13 +/- 3.1 g, respectively; P < 0.001). Loss of specific trace elements (e.g., copper and zinc) during RRT was marked, with considerable heterogeneity between RRT types (e.g., +849 and +2325 mu g/l lost during SLEDf vs. IHD, respectively), whereas effluent losses of copper and zinc decreased during CVVH (effect size relative to IHD, -3167 and -1442 mu g/l, respectively). B vitamins were undetectable in effluent, but experimental modeling estimated 40% to 60% loss within the first 15 minutes of RRT. Conclusion: Micronutrient and amino acid losses are marked during RRT in patients with AKI, with variation between RRT modalities and micronutrients.

METHODS: Data was extracted from hospital informatics systems for all kidney allograft recipients transplanted at our centre between 2007 to 2018. Electronic patient records were manually searched for the latest pre-operative MPS to facilitate data linkage. We excluded recipients with missing pre-operative MPS reports (largely due to ineligibility, symptomatic and referred to cardiology, or external referrals for transplantation). Data with regards to hospitalisation episodes were extracted from Hospital Episode Statistics, a national administrative database of secondary care admissions. Mortality, graft loss, delayed graft function, 1-year rejection and 1-year creatinine values were crosschecked with the UK Transplant Registry.

The second most common cause of hospitalization due to adverse drug reactions in the UK is renal dysfunction due to diuretics, particularly in patients with heart failure, where diuretic therapy is a mainstay of treatment regimens. Therefore, the optimal frequency for monitoring renal function in these patients is an important consideration for preventing renal failure and hospitalization. This review looks at the current evidence for optimal monitoring practices of renal function in patients with heart failure according to national and international guidelines on the management of heart failure (AHA/NICE/ESC/SIGN). Current guidance of renal function monitoring is in large part based on expert opinion, with a lack of clinical studies that have specifically evaluated the optimal frequency of renal function monitoring in patients with heart failure. Furthermore, there is variability between guidelines, and recommendations are typically nonspecific. Safer prescribing of diuretics in combination with other antiheart failure treatments requires better evidence for frequency of renal function monitoring. We suggest developing more personalized monitoring rather than from the current medication-based guidance. Such flexible clinical guidelines could be implemented using intelligent clinical decision support systems. Personalized renal function monitoring would be more effective in preventing renal decline, rather than reacting to it.

Hip fracture is a common injury in older people with a high rate of postoperative morbidity and mortality. This patient group is also at high risk of acute kidney injury (AKI) and chronic kidney disease (CKD), but little is known of the impact of kidney disease on outcome following hip fracture.

The UK-based National Institute for Health and Care Excellence (NICE) has updated its guidance on iron deficiency and anemia management in chronic kidney disease. This report outlines the recommendations regarding iron deficiency and their rationale. Serum ferritin alone or transferrin saturation alone are no longer recommended as diagnostic tests to assess iron deficiency. Red blood cell markers (percentage hypochromic red blood cells, reticulocyte hemoglobin content, or reticulocyte hemoglobin equivalent) are better than ferritin level alone at predicting responsiveness to intravenous iron. When red blood cell markers are not available, a combination of transferrin saturation < 20% and ferritin level < 100ng/mL is an alternative. In comparisons of the cost-effectiveness of different iron status testing and treatment strategies, using percentage hypochromic red blood cells > 6% was the most cost-effective strategy for both hemodialysis and nonhemodialysis patients. A trial of oral iron replacement is recommended in people not receiving an erythropoiesis-stimulating agent (ESA) and not on hemodialysis therapy. For children receiving ESAs, but not treated by hemodialysis, oral iron should be considered. In adults and children receiving ESAs and/or on hemodialysis therapy, intravenous iron should be offered. When giving intravenous iron, high-dose low-frequency administration is recommended. For all children and for adults receiving in-center hemodialysis, low-dose high-frequency administration may be more appropriate.

Background: Older adults are susceptible to dehydration due to age-related changes. This study aimed to investigate the prevalence of clinically diagnosed dehydration in older adult medical emergency hospital admissions and assess the impact on length of hospital stay (LOS) and mortality.Methods: Data were retrieved from the hospital's electronic database relating to all emergency admissions of patients aged >= 65 years between 1 April 2011 and 31 October 2013. The Charlson comorbidity index, LOS and mortality were calculated.Results: Of the 42,553 patients identified, 32,980 (77.5%) were admitted to medical specialties. Dehydration was noted in 2,932 (8.9%) patients and was the primary cause of admission in 190 (0.6%). The prevalence of dehydration also increased with age and comorbidity. Acute kidney injury was reported in 47.7% of patients with dehydration, compared with 15.9% of patients without dehydration, P < 0.001. The median (interquartile range) LOS in patients diagnosed with dehydration was 8 (4-19) days compared with 3 (1-8) days in those without dehydration, P < 0.001. Patients admitted with a primary diagnosis of dehydration had a 17% 30-day mortality and 44% one-year mortality compared with 7% and 25% respectively in patients without dehydration, P < 0.001. Patients diagnosed with dehydration during hospitalisation were twice more likely to die in hospital, HR 2.11 (95% CI 1.92-2.32), P < 0.001, independent of age, gender and comorbidities.Conclusion: A small but significant proportion of hospitalised older adults was diagnosed with dehydration, which was associated with an increase in LOS and mortality, independent of age, gender and comorbidities. (c) 2016 Elsevier Masson SAS and European Union Geriatric Medicine Society. All rights reserved.

Acute kidney injury (AKI) is a common and serious condition with no specific treatment. An episode of AKI may affect organs distant from the kidney, further increasing the morbidity associated with AKI. The mechanism of organ cross talk after AKI is unclear. The renal and immune systems of pigs and humans are alike. Using a preclinical animal (porcine) model, we tested the hypothesis that early effects of AKI on distant organs is by immune cell infiltration, leading to inflammatory cytokine production, extravasation, and edema. In 29 pigs exposed to either sham surgery or renal ischemia-reperfusion (control, n = 12; AKI, n = 17), we assessed remote organ (liver, lung, brain) effects in the short (from 2- to 48-h reperfusion) and longer term (5 wk later) using immunofluorescence (for leukocyte infiltration, apoptosis), a cytokine array, tissue elemental analysis (e.g., electrolytes), blood hematology and chemistry (e.g., liver enzymes), and PCR (for inflammatory markers). AKI elicited significant, short-term (∼24 h) increments in enzymes indicative of acute liver damage (e.g., AST:ALT ratio; P = 0.02) and influenced tissue biochemistry in some remote organs (e.g., lung tissue [Ca 2+ ] increased; P = 0.04). These effects largely resolved after 48 h, and no further histopathology, edema, apoptosis, or immune cell infiltration was noted in the liver, lung, or hippocampus in the short and longer term. AKI has subtle biochemical effects on remote organs in the short term, including a transient increment in markers of acute liver damage. These effects resolved by 48 h, and no further remote organ histopathology, apoptosis, edema, or immune cell infiltration was noted.

The prevalence of malnutrition in acute kidney injury (AKI) is high. Patients with AKI may require renal replacement therapy (RRT), which could result in loss of water-soluble micronutrients. Little is known about these losses in RRT and whether they differ between types of RRT. This study aims to quantify micronutrient losses during RRT in patients with AKI and to compare them in three different RRT modalities: continuous venovenous haemofiltration (CVVH), intermittent haemodialysis (IHD) and sustained low-efficiency diafiltration (SLEDf).

Purpose of reviewA wide range of renal replacement therapies is now available to support patients with acute kidney injury. These treatments utilize diffusion, convection or a combination of these mechanisms to remove metabolic waste products from the bloodstream. It is inevitable that physiologically important substances including micronutrients will also be removed. Here we review current knowledge of the extent of micronutrient loss, how it varies between treatment modalities and its clinical significance.Recent findingsVery few studies have specifically investigated micronutrient loss in renal replacement therapy for acute kidney injury. Recent data suggest that trace elements and amino acids are lost during intermittent dialysis, hybrid therapies such as sustained low-efficiency diafiltration and continuous therapies. Extent of micronutrient loss appears to vary with treatment type, with continuous convection-based treatments probably causing greatest losses.SummaryPatients with acute kidney injury are at high risk of disease-related malnutrition. The use of renal replacement therapy, although often essential for life support, results in loss of micronutrients into the filtrate or dialysate. Losses are probably greater with continuous convective treatments, but it is not yet known whether these losses are clinically significant or whether their replacement would improve patient outcomes.

Title: Remote effects of acute kidney injury in a porcine model. 1 2 David S. Gardner, Simone De Brot, Louise J. Dunford, Llorenc Grau Roma, Simon J.M. 3 Welham, Rebecca Fallman, Saoirse E. O’Sullivan, Weng Oh and Mark A.J. Devonald. 4 5 Schools of Veterinary Medicine and Science and Biosciences, University of Nottingham, 6 Sutton Bonington Campus, Loughborough LE12 5RD, UK; Nottingham University Hospitals 7 NHS Trust Renal and Transplant Unit, City Campus, Hucknall Road, Nottingham, NG5 1PB; 8 School of Graduate Entry Medicine and Health, Royal Derby Hospital, Uttoxeter Road, 9 Derby, DE22 3DT. 10 11 Corresponding author: David Gardner, School of Veterinary Medicine and Science, 12 University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD. UK. Tel +44 13 (0)115 951 6427; Fax +44 (0)115 951 6415; Email david.gardner@nottingham.ac.uk. 14 15 Running title (<30 characters): Effect of AKI on distant organs 16 Abstract word count: 228 17 Main text word count: 4038 words (introduction 960, methods 18 1219, results 661, discussion 1439) 19 Total word count: 6289 (inc legends, tables but excluding references) 20 21 Author contributions 22 D.S.G. and M.A.J.D. designed research; D.S.G., S.D.B., L.J.D., L.G.R., S.J.M.W., R.F., S.O.S. & 23 W.O. conducted the research; D.S.G. and M.A.J.D. co-wrote the manuscript. All authors 24 critically evaluated the paper. D.S.G. conducted the statistical analyses. D.S.G. and M.A.J.D. 25 have primary responsibility for its final content. 26 27 28 Articles in PresS. Am J Physiol Renal Physiol (November 25, 2015). doi:10.1152/ajprenal.00389.2015

Acute kidney injury (AKI) is a common syndrome that is independently associated with increased mortality. A standardized definition is important to facilitate clinical care and research. The definition of AKI has evolved rapidly since 2004, with the introduction of the Risk, Injury, Failure, Loss, and End-stage renal disease (RIFLE), AKI Network (AKIN), and Kidney Disease Improving Global Outcomes (KDIGO) classifications. RIFLE was modified for pediatric use (pRIFLE). They were developed using both evidence and consensus. Small rises in serum creatinine are independently associated with increased mortality, and hence are incorporated into the current definition of AKI. The recent definition from the international KDIGO guideline merged RIFLE and AKIN. Systematic review has found that these definitions do not differ significantly in their performance. Health-care staff caring for children or adults should use standard criteria for AKI, such as the pRIFLE or KDIGO definitions, respectively.These efforts to standardize AKI definition are a substantial advance, although areas of uncertainty remain. The new definitions have enabled the use of electronic alerts to warn clinicians of possible AKI. Novel biomarkers may further refine the definition of AKI, but their use will need to produce tangible improvements in outcomes and cost effectiveness. Further developments in AKI definitions should be informed by research into their practical application across health-care providers. This review will discuss the definition of AKI and its use in practice for clinicians and laboratory scientists.

Background: Living donation is one of the ways to bridge the gap between numbers of donors and recipients on the waiting list for kidney transplantation. Recent legislation allows for altruistic live kidney donation that may be directed or non-directed. The potential living donor requires extensive investigative work up to ensure fitness to donate safely. This assessment adds complexity, time and cost to the overall costs of transplantation. The current study is an assessment of workload implications of live kidney donor assessment at a single centre in the UK. Methods: Data collected prospectively over a 1 year (2012 - 2013) period was reviewed. The end-points were proceeding to donation or not and if not then why not. All the donors were assessed as per an established protocol. Results: Of a total of 141 potential donors investigated, only 18 went on to donate their kidney yielding a ratio of approximately 1 donor for every 6 screened (after excluding donors still on the work up pathway). In 43 cases (31%), live donor work ceased after preliminary telephone interview as the donor was clearly medically unfit or had a BMI >40. Donor factors that precluded kidney donation included medical co-morbidity including hypertension, perceived cardiac risk and history of malignancy or urological problems (25%), Donor withdrew during assessment process (22%), Low donor isotopic GFR (11%) and Anatomical reasons in the donor (1%). Recipient factors that precluded kidney donation included Donation suspended due to recipient medical problems (3%), Donor not needed - recipient transplanted with cadaveric donor (2%), Donation suspended - recipient stable renal function (4%) and Recipient subsequently declined to accept the live donation (4%). 32 potential donors (23%) were being worked up at the conclusion of the study. Conclusion: A significant proportion (31%) of unnecessary clinic assessments are avoided by nurse led telephone screening. Despite this donor medical issues are the commonest reason for non-progression to donation A significant number of donations fail to proceed because of recipient factors and addressing these can potentially reduce the cost of unnecessary or too early assessments that then need repeating.