Trends in adult renal replacement therapy in the UK: 1982-2002.

BACKGROUND: Following the introduction of dialysis and transplantation for the treatment of established renal failure (ERF) 40 years ago, the UK failed to match the achievements of many other countries. AIM: To review progress with treatment for ERF in the UK in the past 20 years. DESIGN: Review of four cross-sectional national studies, and 1997-2002 annual UK Renal Registry data. METHODS: Data on UK patients on renal replacement treatment (RRT) were collated from three sources: European Registry reports for 1982-1990, surveys carried out within the UK in 1993, 1996, 1998 and 2002, and the UK Renal Registry database (1997-2002). Trends in acceptance and prevalence rates, median age, cause of ERF, and treatment modality were analysed and compared with current data from other countries. RESULTS: The UK annual acceptance rate for RRT increased from 20 per million population (pmp) in 1982 to 101 pmp in 2002. This growth was largely in those aged over 65 years, and in those with co-morbidity. Annual acceptance rates for ERF due to diabetes rose from 1.6 to 18 pmp. The prevalence of RRT increased from 157 pmp in 1982 to 626 pmp in 2002. Hospital haemodialysis has become the main modality, and is increasingly being provided in satellite units. Although rising, UK acceptance and prevalence rates are still lower than in many developed countries. DISCUSSION: Despite significant expansion in RRT services for adults in the UK over the last 20 years, there is evidence of unmet need, and need is expected to rise, due to demographic changes and trends in type 2 diabetes. Continuing growth in the already substantial investment in RRT will be needed, unless efforts to prevent the occurrence of ERF are successful.

Regional differences in the provision of adult renal dialysis services in the UK.

BACKGROUND: Provision of renal dialysis varies between UK regions. AIM: To analyse these differences in provision and investigate their causes. DESIGN: Questionnaire-based survey. METHODS: A questionnaire was posted to all renal provider units and renal commissioning groups in the UK. Questions covered issues such as dialysis modalities and patient choice. Data were collected by telephone interview (or post in some cases) and analysed using SPSS. RESULTS: All renal provider units in the UK responded. A full range of modalities was provided by the majority of units. Clear variations in the level and quality of dialysis provision were seen between the UK regions. These included variation in choice of dialysis modality, provision of high-cost drugs, vascular access waiting times, number of support staff and availability of spare dialysis slots. DISCUSSION: The considerable variation between UK regions in the provision of adult renal dialysis services cannot be entirely explained by age or ethnic variation, and is in part due to limited bed space, dialysis machines and support staff, as well as changes in commissioning arrangements. To meet the requirements of the renal national service framework in most regions, changes to policy and funding will be required, such that the relatively new commissioning groups implement more appropriate funding structures in closer dialogue with their provider units.

Dialysis decision making in Canada, the United Kingdom, and the United States.

This study was designed to determine the extent to which differences in criteria for dialysis patient selection and availability of financial resources cause the wide variation in acceptance rates for dialysis in Canada, the United Kingdom, and the United States. We also sought to determine whether there is agreement among nephrologists in the three countries on which patients should not be offered dialysis. We used a cross-sectional survey of all members of the Canadian Society of Nephrology and the Renal Association of Great Britain, and a randomized sample of 800 members of the American Society of Nephrology. Five case vignettes were presented asking for yes/no decisions on offering or not offering dialysis, together with ranking of factors considered important. We also inquired about dialysis resources and physician demographics. We compared responses by country. More nephrologists from the United Kingdom returned responses (83%) than Canadian (53%) or American (36%) nephrologists. American nephrologists offered dialysis more than Canadian or British nephrologists (three of five cases; P < 0.04 to P < 0.001) and ranked patient/family wishes (three of five cases; P < 0.057 to P < 0.0001) and fear of lawsuit (P < 0.04 to P = 0.0012) higher than British or Canadian nephrologists. Canadian and British nephrologists reported their perception of patients' quality of life as a reason to provide (P = 0.0019) or not provide (P = 0.068 to P = 0.0026) dialysis more often than their American counterparts. Despite these differences, nephrologists from each country did not differ by more than 30% on any decision and ranked factors almost identically. Ten percent and 12% of Canadian and British nephrologists, respectively, but only 2% of American nephrologists, reported refusing dialysis due to lack of resources (P < 0.0001). We conclude that the wide variation in dialysis acceptance rates in the three countries is somewhat influenced by differences in patient selection criteria and withholding of dialysis by nephrologists based on financial constraints, but that other factors, such as differences in rates of patient nonreferral for dialysis, contribute more significantly to the variation. Generally agreed on practice guidelines for dialysis patient selection appear possible.

The provision of renal replacement therapy for adults in England and Wales: recent trends and future directions.

We assessed the level of provision of renal replacement therapy for adults in England and Wales. All autonomous main renal units in England (n = 52) and Wales (n = 5) were surveyed in 1996. Data for England were compared to the 1993 National Renal Review. The acceptance rate in England 1995 was 82 (80-85) per million population (p.m.p.) compared with 67 (65-70) p.m.p. in 1991-2. The rate in 1995 in Wales was 109 (98-122) p.m.p. The prevalence rate in England was 476 p.m.p. at end-1995 compared to 393 p.m.p. in 1993, in Wales it was 487 p.m.p. The number of main renal units in England did not rise between 1993 and 1995; capacity was increased by use of more treatment shifts and temporary haemodialysis stations, and by opening more satellite units. The main growth was in hospital haemodialysis. There was an uneven geographical distribution of services. Patients accepted were older with more comorbidity. The use of better-quality processes of dialysis increased. The steady-state position for RRT will not be reached for over a decade. Health authorities will face continued pressure to fund increases in quantity and quality improvements. A stronger evidence base of the effectiveness of therapies, and a national registry to monitor the equity and cost-effectiveness of services are needed.

Dent's disease; a familial proximal renal tubular syndrome with low-molecular-weight proteinuria, hypercalciuria, nephrocalcinosis, metabolic bone disease, progressive renal failure and a marked male predominance.

We describe a familial form of renal Fanconi syndrome characterized by hypercalciuria, low-molecular-weight proteinuria, nephrocalcinosis and slowly progressive renal failure. Males are much more severely affected than females. The patients studied included 15 males and 10 females, and five families with up to three generations involved. Studies of the two largest families described here have already shown that their disease is inherited on the X-chromosome. The series contains the two unrelated patients originally described by Dent and Friedman in 1964 as 'hypercalcuric rickets'.

The care of patients with diabetic nephropathy: audit, feedback, and improvement.

Diabetic nephropathy is the commonest cause of end-stage renal failure in the developed world. The quality of care of 152 patients with diabetic nephropathy was assessed at the time of referral to a single nephrologist. The type II diabetics (62%) were older than the type I diabetics (38%) (mean 65 years vs. 48 years). The mean duration of diabetes was 17 years. Significant cardiovascular disease was present in 52%. There was diabetic retinopathy in 84% of the type I diabetics and 53% of the type II diabetics. Overall, 63% had hypertension at referral (St Vincent Declaration criteria), untreated in 25%. ACE inhibitors were not prescribed in 48% when no contraindications to their use were present. Glycosylated haemoglobin was > 9.1% in 29%. Twenty were prescribed medications inappropriate to their renal function. Of patients with ischaemic heart disease and serum cholesterol > 5.5 mmol/l, 82% were untreated; 82% of patients with secondary hyperparathyroidism were also untreated. At initial referral, many patients' care was sub-optimal. Referral was too late for adequate preparation for renal replacement therapy in 33%. Following a process of education and feedback of the results to referring practitioners, the timing of referral improved. We emphasize the need for closer co-operation between those managing diabetic patients with nephropathy to optimize their care.

Can intensive treatment alter the progress of established diabetic nephropathy to end-stage renal failure?

Diabetic nephropathy is now the leading cause of end-stage renal disease in the Western world, and is associated with a higher patient morbidity and mortality than other causes of renal failure, largely because of associated cardiovascular disease. Numerous studies have elucidated the factors which influence its onset and progression. The St Vincent Declaration in 1994 proposed standards for the appropriate management of patients with diabetic nephropathy. We assessed whether referral to a nephrology clinic attempting to apply these standards influenced the progression of diabetic nephropathy. The results show a significant improvement in blood pressure, glycosylated haemoglobin and serum cholesterol following referral. There was a significant reduction in the rate of decline of renal function following referral in 39% of patients. With the possible exception of diabetic control there were no significant differences in the management of those that did and did not show improvement. The results show that with intensive out-patient clinic monitoring it is possible to improve the quality of patient care, and that even in established diabetic nephropathy it is possible to slow the rate of progression to end-stage renal failure.

Renal histology and immunopathology in distal renal tubular acidosis.

Renal biospy studies are reported from 10 patients with distal renal tubular acidosis (DRTA). On the biopsies from 6 patients who had associated immunological abnormalities immunofluorescent studies for immunoglobulins, complement, and fibrin were performed. Interstitial cellular infiltration and fibrosis were common findings in patients with and without immunological abnormalities, and were usually associated with nephrocalcinosis and/or recurrent urinary infection. No immune deposits were demonstrated in association with the renal tubules. This study shows that DRTA in immunologically abnormal patients is not caused by tubular deposition of antibody or immune complexes. The possibility of cell mediated immune damage is discussed.

Serum ferritin concentration: a reliable guide to iron overload in uremic and hemodialyzed patients.

The inter-relationships between serum ferritin, hemoglobin, serum iron and total body iron stores were studied in 20 patients with chronic renal failure treated conservatively and in 20 patients on regular hemodialysis. There was no relationship between serum iron or transferrin and bone marrow iron deposits, but serum ferritin concentration was a good indicator of increased marrow iron stores. All patients with serum ferritin levels above 300 microgram/l had increased iron stores. Serum ferritin assay is a useful non-invasive technique for detecting iron overload in uremic and hemodialyzed patients.

Incidence of severe acute renal failure in adults: results of a community based study.

OBJECTIVE: To determine the age related incidence of severe acute renal failure in adults in two health districts in England. DESIGN: Prospective study of patients identified as having severe acute renal failure within a two year period; subsequent monitoring of outcome for a further two years. SETTING: Two health districts in Devon. SUBJECTS: Those adults in a population of 444,971 who developed severe acute renal failure (serum creatinine concentration > 500 mumol/l) for the first time during two years, with subsequent fall of the serum creatinine concentration below the index value. MAIN OUTCOME MEASURES AND RESULTS: 125 adults (140 per million total population yearly, 172 per million adults) developed severe acute renal failure, of whom 90 (72%) were over 70. Age related incidence rose from 17 per million yearly in adults under 50 to 949 per million yearly in the 80-89 age groups. In 31 patients (25%) the cause was prostatic disease, which was related to a good prognosis (84% (26) alive at three months). Overall survival was 54% (67) at three months and 34% (42) at two years and was not significantly age related. 18 per million total population yearly (22 per million adult population) received acute dialysis. Referral rate for specialised opinion was 51 per million total population yearly with an estimated appropriate referral rate of 70 per million per year. CONCLUSIONS: The incidence of severe acute renal failure in the community is at least twice as high as the incidence reported from renal unit based studies. Prostatic disease, a preventable and treatable problem, is the most common cause. Survival figures indicate that age alone should not be a bar to specialist referral or treatment.

Incidence of advanced chronic renal failure and the need for end stage renal replacement treatment.

OBJECTIVE: To determine the age related incidence of advanced chronic renal failure in two areas of England. DESIGN: Prospective study of patients newly identified as having advanced chronic renal failure within a two year period; subsequent monitoring of patients' clinical course for a further 26 months. SETTING: Devon and Blackburn. SUBJECTS: Those patients in a population of 708,997 who developed advanced chronic renal failure (serum creatinine concentration greater than 500 mumol/l) for the first time during a two year period. MAIN OUTCOME MEASURES AND RESULTS: 210 Patients (148 per million population per year) developed advanced chronic renal failure, 117 (51%) of whom were over 70. The age related incidence rose from 58 per million per year in those aged 20-49 to 588 per million per year in those aged 80 or over. Only 54% (113) of patients were referred to a nephrologist; 120 patients (57%) needed dialysis or died within three months of presenting without receiving dialysis, and 187 (89%) died or needed dialysis within three years. After those unsuitable for further treatment had been excluded, 78 patients per million population per year aged under 80 needed to start long term renal replacement treatment. CONCLUSIONS: Many patients suitable for renal replacement treatment are still not referred for nephrological opinion and are denied treatment. If the treatment rate in the United Kingdom rose from the 1988 rate of 55.1 per million per year to 78 per million per year then the number of patients receiving treatment would rise to about 800 per million. This is double the present number and has considerable but predictable resource implications for the NHS.

Medullary sponge kidney: abnormalities of renal tubular and glomerular function, and their relationship to clinical features.

This study confirms that medullary sponge kidney (MSK) has a good prognosis, but there is a considerable morbidity in patients with renal calcification; they suffer renal colic, ureteric obstruction, and frequently need operation. There is a high incidence of urinary infection in women. On follow-up, glomerular function is well maintained, although careful testing shows a mild depression of glomerular filtration rate in at least 40%. Proximal tubular function is normal, but abnormalities of distal tubular function are often seen: acidification defects occur in 24% and are associated with nephrocalcinosis, poor urine concentrating ability, and diminished glomerular function. Urine concentration defects occur in 73% and are probably secondary to nephrocalcinosis. Hypercalciuria was present in 19% and was not related to other defects.

Immune-related potassium-losing interstitial nephritis: a comparison with distal renal tubular acidosis.

Six patients with immune-related potassium-losing interstitial nephritis (IRPLIN) are described, and compared with 34 patients with immune-related distal renal tubular acidosis (IRdRTA) and 24 with familial distal renal tubular acidosis (FdRTA). Close similarities were found between IRPLIN and IRdRTA. In our experience, both syndromes are confined to postpubertal women, and are characterized by systemic features of autoimmune disease and a chronic interstitial nephritis which is probably immune-mediated and responsible for the functional tubular defects of the two syndromes. In IRPLIN, a renal potassium-losing state is the main consequence (probably mediated at least in part by renin and aldosterone hypersecretion secondary to renal sodium-losing), and urinary acidification is normal or minimally disturbed; consequently there is no systemic acidosis, and the syndrome is not complicated by nephrocalcinosis or renal bone disease. In IRdRTA, the renal tubular lesion also usually causes potassium depletion, but the most prominent tubular fault is a defect in urinary acidification, which commonly causes metabolic acidosis and often leads to nephrocalcinosis and bone disease. Familial dRTA, in contrast, is equally prevalent in the two sexes and presents at an earlier age than IRPLIN and IRdRTA. Patients with FdRTA and IRdRTA have a similar urinary acidification defect and propensity to acidosis, nephrocalcinosis and bone disease. FdRTA is frequently complicated by renal potassium-losing, but hypokalaemia is less common and less profound than in IRdRTA and IRPLIN, suggesting that immune-related interstitial nephritis has a particular tendency to cause renal potassium-losing.

Ulcerative colitis and glomerulonephritis: is there an association?

Over a 10-year period in one hospital four patients with pre-existing ulcerative colitis presented with biopsy-proven glomerulonephritis. Statistical comparison with epidemiological data suggests that this is a true association.

Vibration sensory threshold: a guide to adequacy of dialysis?

The vibration sensory threshold (VST) is an easy non-invasive reproducible and sensitive bedside test of peripheral nerve function. It is impaired in pre-dialysis uraemic patients with no clinical evidence of peripheral neuropathy; tends to deteriorate during the first year of dialysis after which it remains relatively constant, and returns towards normal within one week of kidney allograft function. It is unrelated to type of dialysis, acetylator status, average serum creatinine values or serum aluminium. VST may be a valuable monitor of the adequacy of dialysis.

Idiopathic hypercalcaemia of chronic dialysis.

Three women on different forms of maintenance dialysis developed persistent steroid-responsive idiopathic hypercalcaemia, with low calcium absorption, severe skeletal decalcification, multiple fractures, and severe clinical problems. Bone histology showed osteomalacia with suppression of osteoblast activity and no hyperparathyroidism. The disease persists at least six months after transplantation. The features are compatible with poisoning by a toxin with many similar properties to aluminium: we only found significant aluminium overload in one of these cases.

Carbamylated hemoglobin: a potential marker for the adequacy of hemodialysis therapy in end-stage renal failure.

Urea can dissociate in vivo to form isocyanic acid which can react with hemoglobin to form carbamylated hemoglobin. Previous work has shown that formation of carbamylated hemoglobin depends upon both the severity and the duration of renal failure. To determine whether carbamylated hemoglobin can be used as an assessment of the adequacy of hemodialysis treatment, we prospectively studied 55 stable patients who regularly attended our hospital dialysis program. Carbamylated hemoglobin was greater in those patients with a Kt/V of < or = 1.1 compared to those with a Kt/V of > 1.1 (120 +/- 8 micrograms VH/gHb versus 99 +/- 7, P < 0.01), and there was a negative correlation with Kt/V (r = -0.37, P = 0.007). There were positive correlations between carbamylated hemoglobin and the time-averaged urea concentration (r = 0.4, P = 0.004), and a negative correlation with the urea reduction ratio (r = -0.37, P = 0.01). Carbamylated hemoglobin may therefore be a useful marker of the degree of uremia, just as glycosylated hemoglobin is used in the assessment of patients with diabetes mellitus.