Search

Background and Aims Haemodialysis vascular access thrombosis (VAT) is a common occurrence that undermines the safe and effective delivery of haemodialysis (HD) and has been associated with anaemia therapy. In the Proactive IV Iron Therapy in Haemodialysis Patients trial (PIVOTAL), proactive high-dose intravenous iron dosing was compared with reactive low-dose intravenous iron dosing. VAT was a pre-specified secondary endpoint. Here we present data detailing the VAT events in PIVOTAL, alongside univariate and multivariate analyses of risk association, testing the hypothesis that VAT may be independently associated with a proactive iron dosing regimen. Method In PIVOTAL 2141 adults with end-stage kidney disease within 12 months of initiating regular HD were randomised 1:1 to either high-dose intravenous iron administered proactively, or low-dose intravenous iron administered reactively, on the basis of monthly Ferritin and Transferrin saturation levels. Erythropoiesis Stimulating Agents were dosed sufficiently to maintain a haemoglobin of 100 to 120g/L. Vascular access use was recorded at baseline and on a monthly basis. VAT was regarded as a safety event with investigators mandated to record such events. VAT was defined clinically, with investigators expected to report thrombotic occlusion of the access (either arteriovenous or catheter thrombosis) significant enough to prevent further effective use without intervention. Baseline demographic, blood pressure and laboratory data underwent univariate analysis with regard to first event of VAT. Primary patient demographics (age, gender, primary renal disease, randomised treatment arm) were put forward for inclusion in a multivariable cox proportional hazards model alongside variables that associated on univariate testing with α Results 2141 eligible patients were randomised, of whom 877/2141 (41.0%) were using a central venous catheter (CVC), 1209/2141 (56.5%) an arteriovenous fistula (AVF), and 55/2141 (2.6%) an arteriovenous graft (AVG) at baseline. Over a median follow up of 2.1 years, 480/2141 (22.4%) experienced a VAT event; 194/887 (21.9%) of CVC patients; 263/1209 (21.8%) of AVF patients; and 23/55 (41.8%) of AVG patients. On univariate testing VAT events associated with diabetes as a cause of kidney failure (HR 1.44, 95%CI 1.19 to 1.74, p Multivariate analysis found diabetes as a cause of kidney failure (HR 1.45, p Conclusion In PIVOTAL, VAT affected nearly one quarter of the cohort over a median of 2.1 years. Diabetes as a cause of kidney failure, active smoking, AVG use, female gender, exposure to digoxin, and exposure to diuretic were independently associated with VAT, but this was not the case with higher iron dosing. ARB use was independently associated with lower risk.

Background and Aims Current guidelines recommend the pursuit of arteriovenous (AV) access over central venous catheter (CVC) access in haemodialysis (HD) populations. The limitations of this approach are increasingly recognised, and are particularly relevant when considering frail patients with relatively high levels of comorbidity and limited life expectancy. In such patients AV access may incur more invasive procedures, whereas CVC access may incur heightened risks of infection. This study aimed to evaluate the association between HD access modality and access complications, hospitalisation and mortality in a cohort of HD patients with frailty. Method We performed a retrospective analysis of prospectively recorded data from the Strathclyde Electronic Renal Patient Record concerning HD patients from 01/10/2017 to 21/09/2019. HD patients with a Rockwood clinical frailty scale (CFS) ≥6 were identified with baseline demographic data being recorded from date of first CFS ≥6 to census date 21/09/19 or death. We recorded the first vascular access modality at study inception and the modality at the time of census or death. Episodes of TCVC associated sepsis were determined using both clinical diagnosis in patient case records and positive blood cultures. Episodes were regarded as separate where positive blood cultures occurred ≥14 days apart. An inpatient admission was regarded as a discharge date ≥24 hours following admission. These were then further categorised as unscheduled or elective. Results 139 patients were identified with CFS ≥6. Median age was 72 years and 51% were female. Median follow-up was 1.1 years with total 50861 observed HD days. 52.3% patients were deceased at census. Table 1 illustrates vascular access modality at initial CFS. CVC accounted for the greatest proportion of dialysis access days (50.3%) compared to AVF (40.7%) and AVG (8.9 %). There was no significant difference in mortality between vascular access modalities over the follow-up period (50.7% CVC; 55% AVF; 54.5% AVG, p=0.18). In total, 5244 HD exposed days (10.3%) were spent as an inpatient during follow-up, of which 5120 (98%) were unscheduled and 119 (2%) were elective. The AVG group had the highest rate of inpatient bed days (138/1000 HD days) when compared to CVC (107/1000 HD days) and AVF (94/1000 HD days). Both AVG and CVC were associated with more inpatient bed days than AVF (p Patients who started with CVC and transitioned to AV access had a rate of 86/1000 HD days. This was significantly lower than those who remained CVC throughout (p=0.0001). There were 24 recorded events of CVC associated sepsis during follow-up, occurring at a rate of 0.8 per 1000 HD days. Rates of CVC associated sepsis were similar between CFS 6 (0.6 per 1000 HD days) and CFS 7 (1.1 per 1000 HD days), p=0.21. The CVC associated staphylococcus aureus bacteraemia (SAB) rate for the overall population was 0.2 per 1000 HD days. AVG sepsis occurred at a rate of 0.2 per 1000 HD days and there were no incidences of AVF sepsis in those who continued with AVF throughout the follow-up period. Conclusion CVC was the most prevalent access modality in this frail HD population. Rates of CVC associated sepsis and SAB were similar to published bloodstream infection rates and existing local data (Murray et al QJM 2014). Although absolute events were low, increasing frailty from CFS 6 “moderately frail” to CFS 7 “severely frail” did not appear to influence rate of CVC associated sepsis. Patients with CVC and AVG had greater inpatient bed days than those with AVF. Transitioning from CVC to AV access reduced inpatient bed days. However, the choice of vascular access modality did not influence mortality overall.

Background and Aims UK NHSBT kidney matching scheme changed in September 2019, aiming to better match graft and patient survival through stratification of donors and recipients into risk quartiles. We present data on two years of transplants aiming to highlight discrepancies between our unit and the model on which the scheme is based, and the potential implications on service provision of its’ introduction. Method We reviewed all deceased donor transplants in our centre in 2015 and 2016. Recipients and donors were re-classified into the risk index quartiles and endpoint data included inpatient days in first year, 1 year eGFR, survival, imaging, and infection episodes. Comparisons were made with NHSBT literature. Results 196 deceased donor transplants were performed. Distribution of D1-4 kidneys to R1-4 recipients in our cohort did not reflect those presented in the allocation scheme models, with our population skewed toward higher risk R4 category (73.4%), including 55 D4R4 (83% of D4 kidneys), see Figure 1. 2.0% had an age difference between donor and recipient of >25years, and 12.8% 15-25 years, compared with the NHSBT proposed targets of 8% and 20% respectively. Within the R4 group, recipients receiving a D4 graft were associated with a higher rate of DGF (41.7%, vs 23.2% D1-D3 grafts, p=0.009), longer index admission (median 11 days vs 8 days, p=0.038) and more readmissions within the first post-operative year (median 18 vs 11 days, p = 0.005) – Figure 2. D4 grafts demonstrated lower mean eGFR at one year (35.7, vs. 54.8 ml/min, p Day ward attendances, bacteraemia, and CT imaging events did not differ by R or D category; D4 was associated with higher rates of transplant ultrasound (5.6 vs R1-3 4.25, p=0.009), and R4 with higher rates of urinary tract infection (3.6 vs R1-3 1.5, p=0.03). Conclusion Firstly, our transplant population is weighted to higher risk R4 recipients; secondly, intended principals of the allocation scheme are already largely being observed. Thirdly, our data does suggest that increasing R4D4 transplants will have a significant impact on transplant centres, with resource burden primarily within the first year. But despite poorer graft function, patient survival appears to be equivalent and improved matching may in the longer term reduce need for re-implantation as the scheme intends.

Background and Aims Haemodialysis (HD) vascular access infections account for approximately 28% of infection-associated hospitalisations in patients with end-stage renal disease1. Traditionally there has been focus on Staphylococcus aureus (S. aureus) infections, however there is increasing recognition of the burden of Gram-negative bloodstream infection (BSI) in the HD population2,3. Epidemiological analysis has enabled surveillance of the impact of antimicrobial protocols on BSI rate and outcome2. Scottish Registry data reflects that access methods are changing alongside the HD population phenotype, with increasing use of arterio-venous graft (AVG) and central venous catheters for incident and prevalent HD access3. In this study, the rate of BSI in a contemporary Scottish HD cohort is reported by microbial species and vascular access type: arterio-venous fistula (AVF), AVG, tunnelled central venous catheter (TCVC) or non-tunnelled central venous catheter (NTCVC). Method The Strathclyde Electronic Renal Patient Record (SERPR) database for the West of Scotland was utilised to obtain retrospective observational data all adult patients attending inpatient and outpatient renal services across seven dialysis units between 1st January 2017 and 31st December 2017. All BSIs were analysed as separate episodes if more than 14 days apart, regardless of the suspected source of infection, and expressed as events per 1000 HD days. The number of days each patient was exposed to each vascular access subtype was calculated utilising the prospectively recorded HD access observations. Prevalent HD vascular access type was noted for each BSI. Results There were 786 patients who underwent HD with 217 503 total HD days over the study period. A total of 147 separate BSIs occurred, involving 115 patients. A total of 168 organisms were encountered in these BSIs. There were 49 BSIs during 126, 674 HD days using AVF access, 14 BSIs during 25, 511 AVG HD days, 81 BSIs during 64, 353 TCVC HD days and 3 BSIs during 965 NTCVC HD days. Table 1 outlines the BSI rates by vascular access and organisms identified Staphylococci-related BSI comprised the majority of events (51.7%), with S. aureus implicated in 47% of these BSIs. Coagulase-negative staphylococci were the most commonly identified organisms in the AVF, TCVC and NTCVC groups, with S. aureus the leading organism in the AVG group. Gram-negative organisms accounted for the next largest proportion of BSIs (27%) and were more prevalent in the TCVC and NTCVC groups. Conclusion AVF access subtype was associated with the lowest BSI rate, and NTCVC the highest which is in keeping with previous studies and one of the drivers for AVF as the preferred HD access type internationally. Staphylococci continue to represent a large proportion of BSIs in this cohort, however other organisms are prevalent. BSIs caused by Gram-negative organisms and Candida species were represented more heavily in the TCVC and NTCVC population, perhaps representing co-morbidity of these groups.

Background and Aims Arteriovenous fistula (AVF) is considered the preferred type of access for maintenance haemodialysis. The creation of an AVF may contribute to maladaptive cardiovascular remodelling. We conducted a study to evaluate the effect of AVF creation on cardiac structure and function in patients with end-stage renal disease (ESRD). Method In this prospective cohort study, patients with ESRD listed for AVF creation underwent cardiac magnetic resonance imaging at baseline and at 6 weeks. All participants had ultrasound measurements of AVF blood flow at 6 weeks. The primary outcome was the change in left ventricular (LV) mass. Secondary outcomes included changes in LV volumes, left atrial volume, LV ejection fraction, LV global longitudinal strain, cardiac output/index, and septal thickness. Results A total of 65 patients were enrolled, of whom 40 had an AVF creation and completed both scans. Patients were divided into 2 groups based on AVF blood flows: 22 in the high flow group (≥ 600mL/min) and 18 in the low flow group (< 600mL/min). On the second cardiac magnetic resonance scan, a mean increase of 7.4 g (95% CI, 1.1–13.7, P=0.02) was observed in LV mass; in the high flow group the mean increase was 15.5 g (95% CI, 7.3–23.8) compared with a small decrease of 2.5 g (95% CI, −10.6 to 5.6) in the low flow group (P=0.003). Significant increases in LV end-diastolic volumes, cardiac output, and cardiac index were also seen after AVF creation (P Conclusion Creation of AVF in adults with ESRD resulted in significant increase of LV myocardial mass early after surgery.

Background: Patients on renal replacement therapy experience higher rates of morbidity and mortality, infection being the second commonest cause of death. In our haemodialysis population, we identify the pathogens, sensitivity patterns, sources of infection and outcomes of Gram-negative bacteraemia. Methods: Data from the NHS Greater Glasgow & Clyde and NHS Forth Valley haemodialysis population were collected July 2011 to April 2014 through an interrogation of the renal unit electronic patient record, and confirmed by an independent search of the Microbiology database. Results: Over 544 377 haemodialysis days, 84 patients experienced 95 Gram-negative bacteraemia events, a rate of 0.175 events per 1000 haemodialysis days, which varied with dialysis modality: non-tunnelled central venous catheters 4.77, arteriovenous grafts 0.24, tunnelled central venous catheters 0.21, and arteriovenous fistulae 0.11 per 1000 haemodialysis days. The commonest sources of bacteraemia were central venous catheters (CVCs) (16.8%, n = 16), infected ulcers (14.7%, n = 14), urinary (10.5%, n = 10), biliary (9.5%, n = 9) and intra-abdominal (9.5%, n = 9). The principal organisms were Escherichia coli (49.5%, n = 47), Enterobacter spp. (13.1%, n = 13), Klebsiella spp. (11.1%, n = 11), Proteus mirabilis (6.1%, n = 6) and Pseudomonas aeruginosa (5.1%, n = 5). Of the Enterobacteriaceae (n = 84), 88% were sensitive to gentamicin, 81% to ciprofloxacin, 91% to piperacillin-tazobactam and 100% were sensitive to meropenem. Three-month case mortality was 25.3% (n = 24). Ten patients (11.9%) had more than one Gram-negative bacteraemia; of these, nine patients (90.0%) were the same causative organism, predominantly E. coli. Conclusions: CVCs and diabetic foot ulcers remain significant risk factors for Gram-negative bacteraemia, highlighting the importance of vascular access planning. Despite good levels of antibiotic sensitivity, the early mortality following Gram-negative bacteraemia remains high, supporting aggressive treatment of such pathogens.