Management of chronic kidney disease

Epidemiological studies have shown that renal disease is common. In the United States, the third national health and nutrition survey (Nhanes III) has shown that 4.3% of the population has chronic kidney disease with a glomerular filtration rate of 30-59 ml/min/1.73 m², and 0.2% has chronic kidney disease with a glomerular filtration rate of less than 15-29 ml/min/1.73 m².¹ In the United Kingdom, screening for renal disease by retrospective surveys of plasma creatinine measurements from chemical pathology laboratories serving defined populations has shown a similar prevalence of more severe chronic kidney disease (0.2-0.5% general population).²,³ In both studies, patients were followed longitudinally; very few developed end stage renal disease, as the major cause of death was cardiovascular disease. So what model of care should we use to look after this large number of patients with varying degrees of chronic kidney disease?

Increasing numbers of studies have shown that the presence of chronic kidney disease is an independent and significant cardiovascular risk factor in the general population and in those with pre-existing cardiovascular disease.⁴,⁵ Furthermore, the complications of renal failure such as anaemia and hyperparathyroidism develop at higher glomerular filtration rates than usually thought and are common when the rate is as high as 30-40 ml/min. In the study of Stevens et al, haemoglobin was less than 11g/dl in 27.5% of the patients with chronic kidney disease not referred to renal clinics.²

Patients who have potentially reversible causes of renal failure or whose renal function is deteriorating rapidly need to be identified to allow for rapid assessment by a nephrologist. The question remains how best to manage the remaining large cohort of patients with stable chronic kidney disease of varying degrees. The use of calculated glomerular filtration rate is likely to identify patients with less severe degrees of chronic kidney disease, who may be missed if serum creatinine is used to assess kidney function. We do not have enough nephrologists or nephrology outpatient clinics to manage the workload that this would generate, and evidence shows that using nephrology outpatient clinics is not the most effective means of managing chronic diseases.⁶ Such patients would be best managed in a partnership arrangement between primary and secondary care. In this model, many professional groups including general practitioners with a specialist interest, specialist nurses, pharmacists, and dieticians all have a role in the management of the chronic condition. Patients also need to take on a greater responsibility for their own care.

Patients with a glomerular filtration rate of less than 15 ml/min are highly likely to require renal replacement therapy and will need close follow-up to prepare them for this event. The renal national service framework has highlighted the importance of involving patients in this process, and considerable time will also be needed to inform them fully of the treatment options available.⁷ Such care can best be provided in a nephrology clinic, with access to support from renal specialist nurses, renal dieticians, and vascular access surgeons.

Patients whose glomerular filtration rate is between 15 ml/min and 30 ml/min may also require considerable input from specialists. However, many of these patients remain stable for long periods, and the interventions required could easily be managed by a specialist nursing clinic with support from a nephrologist. Seemingly complex issues such as the recognition and treatment of renal anaemia and hyperparathyroidism can be managed by using practice guidelines.

For the larger number of patients with a glomerular filtration rate between 30 ml/min and 60 ml/min the main interventions required are basic ones. Common approaches exist to preventing the progression of chronic kidney disease and cardiovascular disease. These include tight control of blood pressure, correcting lipid abnormalities, and various lifestyle changes including the cessation of smoking.⁸,⁹ The general practitioner with a specialist interest and many non-specialist nurses working within primary care should be able to contribute to this process, as long as they are able to work to guidelines and have ready access to medical support from general practitioners and advice from renal specialist nurses and nephrologists.

The challenge is for primary and secondary care to set up together the necessary systems to implement such a model. These systems may require novel approaches to commissioning and clarity with regard to clinical responsibility for the patients. As the patients move through this pathway, they will need to be managed according to guidelines, with targets for the control of blood pressure, diabetes, lipids, and smoking. This will have to be provided in a patient centred environment, which gives the patient a role and an incentive for achieving these goals. With optimum treatment cardiovascular complications can be reduced and patients can have the progression to end stage renal disease delayed by many years.

Considering this approach to managing chronic renal disease is the only way in which we are likely to cope with this large cohort of patients and to produce the results that will reduce the impact of end stage renal failure and reap a sizeable financial reward for the health services.