Chronic kidney disease (CKD) is a common long-term condition, affecting 5–7% of the adult population (Couser et al, 2011). It is more frequently seen in people with diabetes, hypertension and in the elderly population, who often self-manage their condition with support from practice nursing teams. CKD is more common and worsens more quickly in people from lower socioeconomic groups and from black, Asian and minority ethnic groups (Kidney Research UK, 2018). This suggests that these groups in particular may benefit from extra support to manage their CKD. Because of the association between diabetes and vascular disease, CKD is also common in people who have multiple long-term conditions (Guy's and St Thomas' Charity, 2018).
People with multiple long-term conditions often have complex health needs and receive advice from multiple specialist teams. This increases the risk of fragmented care, and the NHS Long Term Plan (NHS, 2019) has highlighted the key role of community teams to coordinate care for these patients. Primary care teams are responsible for prescribing most medications and are usually the first called when a patient feels unwell. It is essential that practice nurses have a good understanding of CKD, the rationale behind treatment pathways, and when to seek specialist advice to target those at greatest risk, reduce complications and help people to live well for longer. This article will explain the importance of screening for the complications that may develop as kidney function worsens, and how to recognise and treat symptoms related to CKD should they arise.
Definition of chronic kidney disease
CKD is used as a general term used when someone has signs of abnormal kidney function – either a reduction in estimated glomerular filtration rate (eGFR) to less than 60 ml/min/1.73 m2 or an increase in proteinuria, albumin:creatinine ratio (ACR) greater than 3 mg/mmol that persists for at least 3 months (National Institute for Health and Care Excellence (NICE), 2014). CKD has a variety of causes (Box 1). It is important that treatable causes are considered and patients are referred for specialist investigation and treatment when needed.
Box 1.Causes of chronic kidney disease
- Diabetes
- Hypertension
- Vascular disease
- Glomerular disease (eg immunoglobulin A nephropathy)
- Auto-immune disease (eg lupus)
- Problems with the urinary tract (eg enlarged prostate)
- Genetic disease (eg polycystic kidney disease)
CKD varies in severity from mild (Stage 3a) to kidney failure (Stage 5) (Table 1). Stages 1 and 2 are indicators of increased risk of worsening kidney function in the future, either due to a structural abnormality in the urinary system or the presence of proteinuria. Patients with Stage 1 or 2 should be reassured that their kidneys are removing waste normally, but they should also be advised of the importance of monitoring – often an annual blood test and blood pressure check – and the benefits of adopting a healthy lifestyle. Most patients with CKD will have Stage 1 to 3b, with relatively few going on to develop Stage 4 or 5.
Table 1. International staging of chronic kidney disease
| Stage | Estimated glomerular filtration rate | Kidney function | Estimated prevalence (%) |
|---|---|---|---|
| 1 | >90 | Normal or high, with structural abnormality or albuminuria | 4.7 |
| 2 | 60–90 | Mildly decreased, with structural abnormality or albuminuria | 2.9 |
| 3a | 45–59 | Mildly to moderately decreased | 5.0 |
| 3b | 30–44 | Moderately to severely decreased | 1.7 |
| 4 | 15–29 | Severely decreased | 0.4 |
| 5 | <15 | Kidney failure | 0.2 |
Patients with Stage 3 rarely have symptoms, while those with Stage 4 or 5 become increasingly symptomatic. Severe symptoms may be improved with dialysis or kidney transplantation, although these treatments are not suitable for all and an unknown number of patients die from complications associated with kidney disease each year.
Worsening of CKD can often be delayed through good management of risk factors and lifestyle modification (Rainey, 2018) but kidney function will deteriorate in some patients, increasing the risk of complications and symptoms.
Medicines in chronic kidney disease
In Stage 3 CKD, medications will often be prescribed to control blood pressure and diabetes. It is important that patients avoid nephrotoxic medications where possible, such as non-steroidal anti-inflammatory drugs (NSAIDs). Some medications are excreted via the kidneys, therefore doses may need to be adjusted if kidney function worsens because of extended half-life or accumulation of metabolites. For example, metformin should be stopped when eGFR is less than 30 ml/min/1.73m2 because of the risk of lactic acidosis in acute illness.
Prescribers should be aware that some medications may be ineffective when kidney function is poor – for example, nitrofurantoin is ineffective against urinary tract infections when eGFR is less than 45 ml/min/1.73m2 as its efficacy depends on renal secretion into the urinary tract. Specific medications should be checked in the British National Formulary (Joint Formulary Committee, 2019) or advice sought from pharmacists. Some CKD patients may be receiving specialist renal care, such as those with autoimmune diseases being treated with immunosuppression.
The potential side-effects of treatments such as steroids should be considered when patients develop symptoms and advice should be sought from a specialist as necessary.
Common complications
A reduction in any kidney function (Box 2) can lead to biochemical or haematological abnormalities. These can often be detected through blood tests before patients develop any symptoms, therefore it is important that they are monitored during patients' regular reviews. Prompt identification and treatment of abnormalities can reduce complications and prevent the development of symptoms, providing primary care teams with a key role to ensure that correct monitoring tests are undertaken and refer for specialist advice if needed.
Box 2.Functions of the kidney's homeostasis
Removal of metabolic waste (urea and creatinine)
| Excretion |
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| Regulation |
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| Metabolic/hormonal |
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A summary of the common complications of CKD and the potential role of practice nurses in their management is shown in Table 2. CKD patients are at increased risk of infection and should be offered influenza vaccination annually and pneumococcal vaccination.
Table 2. Common complications of chronic kidney disease
| Complications | Screening | Cause in CKD | Alternative causes to consider | Treatment in CKD | Benefits of treatment | Potential role of practice nurses |
|---|---|---|---|---|---|---|
| Anaemia (haemoglobin <110 g/l) |
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| Mineral bone disease (phosphate >1.5 mmol/l, PTH rising or above reference range) |
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| Acidosis (Serum bicarbonate <20 mmol/l) |
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| Hyperkalaemia (serum potassium >5.5 mmol/l) |
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| Hypertension (blood pressure >140/90 mmHg not diabetes or >130/80 mmHg with diabetes) |
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CKD: chronic kidney disease, eGFR: estimated glomerular filtration rate, PTH: parathyroid hormone, U&E: blood test for urea and electrolytes, ACEI: angiotensin converting enzyme inhibitor, ARB: angiotensin receptor blocker, NICE: National Institute for Health and Care Excellence
From: National Institute for Health and Clinical Excellence (2011; 2014; 2015; 2016); Kidney Disease: Improving Global Outcomes (2017)Signs and symptoms
Symptoms from CKD usually develop slowly over time and are rarely visible to others. Many patients with CKD do not report any symptoms in the early stages, although it has been suggested that some experience symptoms but they are not always aware that they may be related to CKD (Pugh-Clarke et al, 2017). It is important to ask patients about symptoms, acknowledge that they occur and support them to develop strategies to cope.
For patients with multiple long-term conditions, it can be difficult to determine whether symptoms are due to CKD or because of another health condition and alternative causes should then be considered. The following symptoms experienced by CKD patients become increasingly common as kidney failure worsens, and support and treatment should be offered as needed.
Fatigue
Fatigue is often the first symptom that patients with CKD develop and may have many causes. Patients often describe extreme exhaustion that can make it difficult to work full-time, with financial worries adding to anxiety. Patients who report feeling increasingly tired should be screened for anaemia and treated appropriately. Disturbed sleep due to nocturia, restless legs or night cramps may also contribute to fatigue.
Nocturia
Another common symptom in earlier stages of CKD is passing urine more frequently at night as the kidneys lose the ability to concentrate urine as kidney function decreases. Passing urine more frequently may alternatively be caused by high blood sugar in uncontrolled diabetes, an over-active bladder or urinary infections. Unfortunately, there is no treatment for nocturia linked to CKD, but patients should be reassured that this is normal and encouraged to remain well-hydrated.
Night cramps
Leg cramps, especially at night, can be very bothersome for patients with CKD, leading to disturbed sleep and worsening fatigue. Patients should be advised to try gentle stretching exercises before bed, but frequent cramps that disturb sleep may also be reduced with quinine sulphate tablets taken at night. Some patients report improvement by drinking a glass of tonic water before bed, although there is no evidence to support this and the amount of quinine consumed is very small.
Restless legs
Restless legs syndrome is a condition where people have an overwhelming urge to move their limbs, often at night, and it can lead to disturbed sleep. It may also be experienced as an unpleasant crawling sensation in the feet, calves or thighs. The cause is unknown but it may be worsened by iron deficiency, which should be treated. Patients should be advised to try moderate exercise during the day and to avoid alcohol and caffeine.
Gout
Gout frequently occurs in CKD due to an accumulation of uric acid. It occurs more frequently in patients taking diuretics and NSAIDs should be avoided. A short course of colchicine should be considered for acute exacerbations. Regular allopurinol can be effective at preventing gout and should be discussed with patients with recurrent episodes.
Back pain
Back pain is rarely caused by CKD and should be investigated just as it normally would be for people who do not have CKD. An exception is polycystic kidney disease, where burst or bleeding cysts can cause acute pain and are often accompanied by haematuria. Patients with polycystic kidney disease should try simple analgesia such as paracetamol and seek advice from their kidney specialist if this is ineffective.
Reduced libido
Many patients with CKD experience reduced libido, and men may experience erectile dysfunction. This can cause stress in relationships and understanding that reduced libido is a consequence of CKD can be helpful for patients and their partners. Reduced libido may be improved by correction of anaemia and men should be referred to erectile dysfunction clinics if required.
Itching
Itching is one of the most life-affecting symptoms reported by patients with CKD. It is caused by accumulation of urea or phosphate and often persists in patients undergoing dialysis. Patients should be advised to choose loose cotton clothing and bedding and to keep the skin well-hydrated with non-perfumed moisturisers. There is evidence that gabapentin and pregabalin can help to reduce severe itching, although these should be used cautiously because of the risk of side effects. Alternative causes of itching such as insect bites or allergies should be considered, particularly in patients with stable kidney function.
Swollen ankles
Swollen ankles may occur due to Stage 5 CKD, or as a result of heart failure, and all patients should be advised to reduce their salt intake to prevent fluid retention. It also occurs as a common side-effect of amlodipine and it may be seen in frail patients who spend long periods of time sitting. The risks and benefits of alternative antihypertensives should be discussed with patients who report swelling related to amlodipine, and patients can be encouraged to increase exercise and/or elevate their legs if swelling is related to sitting.
Swollen ankles can be treated with a diuretic if needed, although this will often cause a reduction in kidney function – this should not cause concern if eGFR stabilises after an initial drop. When swelling does not improve with diuretics, nephrotic syndrome (characterised by high protein:creatinine ratio (PCR) of >300 mg/mmol and reduced serum albumin of <25 g/L) should be considered and patients should be referred for specialist advice.
Breathlessness
Breathlessness is rarely seem in Stage 3 or 4. Those reporting breathlessness on exertion should be screened for anaemia and heart failure should be considered. Patients who have recently started exercising should be reassured that breathlessness is a normal response to activity and advised to increase intensity of exercise gradually. Patients with Stage 5 may develop breathlessness at rest due to fluid overload or acidosis, and specialist advice should be sought urgently if suspected.
Appetite, taste changes, nausea and vomiting
Reduced appetite is not usually experienced by patients until CKD is advanced, and occurs due to the build-up of waste products in the blood, such as urea. Patients with Stage 5 may also describe a ‘metallic taste’ in the mouth and suffer with nausea and vomiting. Alternative causes of vomiting should be considered, such as viruses or food poisoning (it can be helpful to ask if other members of the household are experiencing symptoms) or gastroparesis due to diabetes. Treatment for vomiting should be considered to reduce the risk of acute kidney injury caused by dehydration. Patients with polycystic kidney disease may experience reduced appetite even when kidney function is good due to reduced abdominal space as a result of enlarged kidneys, and sometimes liver. Reduced appetite or vomiting due to uraemia in Stage 5 may be an indication to commence dialysis.
Cognitive impairment
In advanced Stage 5, urea passes from the blood into the brain, leading to cognitive impairment. Removal of urea through dialysis will improve poor cognition related to uraemia. It is important that discussions about future dialysis occur while patients have the capacity to make decisions; patients should be referred for specialist advice once they reach Stage 4. Patients with severe cognitive impairment due to uraemia may require dialysis before they are able to take make decisions about ongoing treatment.
Planning for Stage 5
Complications and symptoms become more common and increase in severity in Stage 5 CKD. Patients with Stage 4 (eGFR <30 ml/min/1.73 m2) should be referred to a renal specialist for advice about managing complications and planning for Stage 5. Some patients will be able to undergo kidney transplantation before needing to start dialysis, while others will undertake dialysis treatment when kidney failure worsens. Planning treatment takes time; this allows patients to consider all options and decide on a preferred treatment, to complete transplant assessments including donor assessments for those with a living donor, to establish permanent access for dialysis (insertion of peritoneal dialysis catheter for peritoneal dialysis or formation of an arteriovenous fistula for haemodialysis), and should start at least 1 year before treatment is likely to be needed (NICE, 2018). This can be difficult to predict; therefore, in practice, it should be considered once eGFR <20 ml/min/1.73 m2. Patients with severe frailty will not be suitable for kidney transplantation and may find dialysis onerous without any increase in life expectancy. Such patients may find hospital visits difficult and may prefer to receive their care from community teams.
Practice nurses know their patients well, therefore they have an important role in guiding renal services on the appropriateness of aggressive or invasive treatments, while renal services should have mechanisms to support and advise primary care teams about patients who elect not to undertake dialysis. Close working between primary, secondary and palliative care teams to manage symptoms can help such patients remain well at home, with an increased likelihood that they will die in their preferred place of death.
Conclusion
Every general practice list will include many people with CKD, but probably only one or two who are being treated with dialysis or a kidney transplant. Practice nurses have a key role in helping to identify and manage complications and symptoms of CKD to improve quality of life. Good coordination between primary care and renal services can enable patients to receive their care in the most appropriate setting.
Key Points
- Chronic kidney disease (CKD) is a common condition, particularly in people living with multiple long-term conditions
- Complications may be detected through blood tests, allowing prompt treatment to reduce their severity
- Recognition and treatment of symptoms from CKD can help to improve quality of life
- Frail patients may not benefit from dialysis and close working between community and renal services can enable them to receive high-quality care at home
CPD reflective questions
- What could you change in your practice to improve support for your patients with chronic kidney disease (CKD)?
- Do you feel confident discussing the complications and symptoms of CKD with your patients?
- How can closer working between community and renal teams enhance the care for frail patients living with CKD?