Lisa Crowley

Use of Electronic Results Reporting to Diagnose and Monitor AKI in Hospitalized Patients

BACKGROUND AND OBJECTIVES Many patients with AKI are cared for by non-nephrologists. This can result in variable standards of care that contribute to poor outcomes. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS To improve AKI recognition, a real-time, hospital-wide, electronic reporting system was designed based on current Acute Kidney Injury Network criteria. This system allowed prospective data collection on AKI incidence and outcomes such as mortality rate, length of hospital stay, and renal recovery. The setting was a 1139-bed teaching hospital with a tertiary referral nephrology unit. RESULTS An electronic reporting system was successfully introduced into clinical practice (false positive rate, 1.7%; false negative rate, 0.2%). The results showed that there were 3202 AKI episodes in 2619 patients during the 9-month study period (5.4% of hospital admissions). The in-hospital mortality rate was 23.8% and increased with more severe AKI (16.1% for stage 1 AKI versus 36.1% for stage 3) (P<0.001). More severe AKI was associated with longer length of hospital stay for stage 1 (8 days; interquartile range, 13) versus 11 days for stage 3 (interquartile range, 16) (P<0.001) and reduced chance of renal recovery (80.0% in stage 1 AKI versus 58.8% in stage 3) (P<0.001). Utility of the Acute Kidney Injury Network criteria was reduced in those with pre-existing CKD. CONCLUSIONS AKI is common in hospitalized patients and is associated with very poor outcomes. The successful implementation of electronic alert systems to aid early recognition of AKI across all acute specialties is one strategy that may help raise standards of care.

Tissue Advanced Glycation End Product Deposition after Kidney Transplantation

Background: Tissue advanced glycation end products (AGEs) accumulate in chronic kidney disease (CKD) and are a measure of cumulative metabolic stress. Measurement of tissue AGEs by skin autofluorescence (SAF) correlates well with cardiovascular outcomes in dialysis patients. SAF levels in transplant recipients relative to CKD and dialysis patients have not been previously studied, and the impact of transplantation on SAF levels in dialysis patients is unknown. Methods: SAF was measured using an AGE reader in 66 patients who had received a kidney transplant. Values were compared to those obtained in 1,707 patients with CKD stage 3 and in 115 patients on dialysis. Results: Mean SAF in transplant recipients [2.81 ± 0.64 arbitrary units (AU)] was significantly lower than in patients on haemodialysis (3.73 ± 0.88 AU) and peritoneal dialysis (3.57 ± 0.75 AU; p < 0.001), but was no different from CKD stage 3 (2.79 ± 0.66 AU; p = 0.42). In the transplant group, SAF correlated most strongly with age (r = 0.316). There was no correlation between SAF and estimated glomerular filtration rate or renal replacement therapy vintage. A small cohort of patients with SAF recorded on dialysis and following transplantation showed a drop in SAF over a mean time of 16 months after transplantation. Discussion: Tissue AGE values in kidney transplant recipients are significantly lower than in patients receiving dialysis and similar to those in patients with CKD stage 3. Our data suggest that transplantation may be associated with a reduction in tissue AGEs, and this might be an important component of the observed reduction in cardiovascular risk in transplant recipients compared to patients on dialysis.

Remote ischaemic conditioning—therapeutic opportunities in renal medicine

Following ischaemic insult, tissue damage is extended after reperfusion, known as an ischaemia reperfusion injury. Ischaemic conditioning—the application of transient, non-lethal, episodes of ischaemia—reduces the effect of a larger ischaemic insult, and limits the reperfusion injury. How this phenomenon might be exploited as a therapeutic treatment is now the subject of a number of clinical trials. From initial trials focusing on the mitigation of cardiac injury, interest has expanded to examine the potential for its use as an adjunctive therapy in different clinical scenarios, including renal medicine. In this Review, we discuss different forms of conditioning, potential molecular mechanisms underpinning its effect, and potential applications in the setting of acute kidney injury, chronic kidney disease and end-stage renal disease.

Circulating endotoxaemia and frequent haemodialysis schedules.

Background/Aims: Endotoxaemia, a driver of systemic inflammation, appears to be driven by dialysis-induced circulatory stress in haemodialysis (HD) patients. More frequent HD regimens are associated with lower ultrafiltration requirements, improved haemodynamic stability and lower systemic inflammation. This study investigated the hypothesis that more frequently dialysed patients, with reduced exposure to dialysis-induced haemodynamic perturbation, would have lower circulating endotoxin (ET) levels. Methods: A cross-sectional study of 86 established HD patients compared three groups: conventional HD 3× per week (HD3, n = 56), frequent HD 5-6× per week (SDHD, n = 20), and nocturnal HD (NHD, n = 10). Data collection included ultrafiltration volume and rate, serial blood pressures and blood sampling with quantification of ET, troponin T and high-sensitivity CRP (hsCRP). Results: Pre-dialysis serum ET was highest in the conventional HD group (HD3 0.66 ± 0.29 EU/ml vs. NHD 0.08 ± 0.04 EU/ml). Across the study population, severity of endotoxaemia was associated with higher ultrafiltration rates, degree of intradialytic hypotension, troponin T and hsCRP levels. NHD patients had the lowest ultrafiltration requirements, the greatest haemodynamic stability and lower ET levels. Conclusion: More frequent HD regimens are associated with lower levels of circulating ET compared with conventional HD. Reduced ET translocation may be related to the greater haemodynamic stability of these treatments, with superior maintenance of splanchnic perfusion.

UK Renal Registry 16th Annual Report: Chapter 15 Epidemiology of Reported Infections amongst Patients Receiving Dialysis for Established Renal Failure in England from May 2011 to April 2012: a Joint Report from Public Health England and the UK Renal Registry

INTRODUCTION Infection remains one of the leading causes of mortality in established renal failure patients receiving renal replacement therapy (RRT). METHODS Data were submitted to Public Health England (PHE) by NHS acute Trusts via Health Care Associated Infection Data Capture System (HCAI-DCS) including whether the patients were receiving dialysis. Individual renal units then confirmed the record either directly via the database or after being contacted. Data were collected for the period 1st May 2012 to the 30th April 2013. RESULTS There were 31 episodes of MRSA bacteraemia, an overall rate of 0.13 per 100 dialysis patient years, representing a further year-on-year fall in MRSA rate. There were a higher number of MSSA episodes, 372 in total,with an overall rate of 1.59 per 100 dialysis patient years. The number of episodes of E. coli and C. difficile were 308 (1.32 per 100 dialysis patient years) and 123 (0.55 per 100 dialysis patient years) respectively. The presence of a central venous catheter was associated with an elevated risk of MRSA and MSSA bacteraemia. CONCLUSIONS We present data relating to infections in renal dialysis patients reported to PHE in one year. The rate of MRSA bacteraemia episodes in England continues to fall. There is a higher rate of MSSA infections.We also report the results of the second year of E. coli and C. difficile data collection. Future cycles will give further ideas of the trend in incidences of these infections. Further work to refine the definitions and data collection is necessary to ensure consistency of reporting across centres.

Chapter 12 Epidemiology of Staphylococcus Aureus Bacteraemia Amongst Patients Receiving Dialysis for Established Renal Failure in England in 2009 to 2011: A Joint Report from the Health Protection Agency and the UK Renal Registry

Introduction: Infection remains one of the leading causes of death in patients with end-stage renal failure (ESRF) receiving dialysis. Since April 2007, all centres providing renal replacement therapy in England have been required to provide additional data on patients with Methicillin Resistant Staphylococcus Aureus (MRSA) infection. From January 2011 this has also been required for patients with Methicillin Sensitive Staphylococcus Aureus (MSSA). MRSA data for 2009–2011 and the first 6 months of MSSA data are reported. Methods: Potential bacteraemia were identified by the Health Protection Agency based on clinical details provided and the clinical setting. The records were ‘shared’ with the parent renal centre who then complete the additional data on the HCAI-DCS website. Centres were also contacted by phone and email as a further validation step. Results: From April 2009–2010 there were 77 confirmed episodes of MRSA bacteraemia at a median rate of 0.25 per 100 prevalent dialysis patients. This number decreased to 61 episodes between April 2010–2011 at a median rate of 0 per 100 prevalent dialysis patients. Overall there has been an 82% reduction in absolute episodes since the first year of mandatory reporting in 2007. The incidence of bacteraemia in patients with a central venous catheter was approximately six fold higher than in those with an AV fistula. From 1st January to 30th June 2011 there were 160 episodes of MSSA bacteraemia with a rate of 1.06 episodes per 100 dialysis patients, again the risk was six fold higher in patients with a CVC. Conclusions: Overall rates of MRSA bacteraemia in dialysis patients continued to fall although there remained variation between renal centres. Initial data from the early days of MSSA reporting suggested high rates of infection and an even greater variation between renal centres. This requires confirmation from future data collection.

UK Renal Registry 18th Annual Report 2015

The UK Renal Registry (UKRR) continues to provide a national source of NHS healthcare data on patients dependent on renal replacement therapy (RRT) across the four nations. Using electronic reporting and substantial integration across the 71 adult and 13 paediatric renal centres independent audit and analysis of dialysis and transplant activity and care across the UK is provided. The UKRR is part of the UK Renal Association and is funded directly by participating renal centres through an annual capitation fee per patient per annum, currently £19 or 0.01% of annual RRT running costs. The UKRR remains relatively unique amongst renal registries in publishing both centre-specific analyses of indicators of quality of care, such as haemoglobin and also ageadjusted survival statistics for each renal centre [1].

Creation of an Arteriovenous Fistula Is Associated with Significant Acute Local and Systemic Changes in Microvascular Function

Background: Native arteriovenous fistulae (AVF) are the vascular access of choice for haemodialysis. The consequences of AVF formation on microvascular function, locally or systemically, are unknown. Methods: We recruited 43 predialysis patients undergoing AVF formation. Patients were studied 2 weeks prior to the planned AVF operation and 2 weeks postoperatively. Thirteen patients with failed AVF were subsequently utilised as sham controls. Laser Doppler perfusion imaging was used to measure subcutaneous microvascular blood flow. Microvascular function was assessed as an increase in perfusion in response to iontophoretic administration of vasodilatory stimuli assessing endothelial-dependent (ED) and non-endothelial-dependent (NED) vasodilatation. Results: Patients with successful AVF formation had a significantly reduced ED vasodilatation in the fistula arm (-36 ± 46%, p < 0.001). Only NED vasodilatation was significantly reduced in the non-fistula arm (23 ± 40%, p = 0.01). Patients who had an unsuccessful AVF operation exhibited no recordable changes. Conclusions: Formation of an AVF was associated with local and remote changes in microcirculation. Further assessments are underway to examine the contributions of local shear stress, vasoreactive substances and the autonomic responses. Although the clinical significance of these findings is not yet clear, it is intriguing that AVF formation is associated with such widespread and profound changes in microperfusion.

The Impact of Hemodialysis on Segmental and Global Longitudinal Myocardial Strain

BACKGROUND Strain analysis derived from the analysis of speckle tracked imaging echocardiography can be used to examine ventricular contractile functions. In this study, we examined the relationship of hemodialysis (HD)-induced circulatory stress with overall ventricular function assessed according to global longitudinal strain (GLS) and segmental distribution of strain. METHODS This prospective observational study included 104 conventional HD patients at Royal Derby Hospital. Averaged values of segmental and GLS were determined from the echocardiography of these patients before and at peak dialysis. These values were compared with the reference values of healthy individuals, correlated with their demographic characteristics, and the effect on survival was assessed. RESULTS The global strain value was -11.5% ± 4.42, and the segmental strain values were significantly greater in HD patients than in healthy individuals by 2.7%-9.8% (P < 0.001). The strain values were not significantly different before dialysis and at peak dialysis (P > 0.05), except within the basal lateral segment (P = 0.01). The adjusted hazard ratio for mortality was 4.3 (95% confidence interval, 1.2-14.9; P = 0.021) when > 80% of the segments exhibited more than the mean of segmental strain values. For the 46 patients who died, there were statistically significant negative correlations between survival time and GLS (r = -0.30; P = 0.04). CONCLUSIONS Global and segmental strain measured using speckle tracked imaging provides information relating to the effects of HD-induced cardiac injury. The segmental strain abnormalities in the watershed area of the left ventricle suggest a higher degree of vulnerability to HD-induced demand ischemia.

UK Renal Registry 17th Annual Report: Appendix B Definitions and Analysis Criteria

The take-on population is defined as all patients over 18 who started renal replacement therapy (RRT) at UK renal centres and did not have a recovery lasting more than 90 days within 90 days of starting RRT. The treatment timeline is used to define take-on patients as follows. If a patient has timeline entries from more than one centre then these are all combined and sorted by date. Then, the first treatment entry gives the first date of when they received RRT. This is defined as a ‘start date’. However, in the following situations there is evidence that the patient was already receiving RRT before this ‘start date’ and these people are not classed as takeon patients: