Chronic Kidney Disease (CKD)

Definition

Chronic Kidney Disease (CKD) is a long-term condition characterised by a gradual loss of kidney function over time. CKD is classified into stages based on the glomerular filtration rate (GFR) and the presence of kidney damage markers, such as proteinuria.

Aetiology

CKD can result from various causes, including:

Diabetes mellitus: Leading cause of CKD.
Hypertension: Second leading cause of CKD.
Glomerulonephritis: Inflammation of the kidney's filtering units.
Polycystic kidney disease: Genetic disorder causing cysts in the kidneys.
Recurrent urinary tract infections or obstruction.
Autoimmune diseases: Such as lupus nephritis.
Nephrotoxic medications and toxins.

Pathophysiology

CKD involves a progressive decline in kidney function, characterised by a decrease in GFR and an increase in serum creatinine. The loss of kidney function can lead to the accumulation of waste products, fluid imbalance, and electrolyte disturbances. Over time, CKD can progress to end-stage renal disease (ESRD), requiring dialysis or kidney transplantation.

Risk Factors

Diabetes mellitus.
Hypertension.
Family history of CKD.
Cardiovascular disease.
Obesity.
Smoking.
Advanced age.
Ethnicity: Higher prevalence in African, Asian, and Hispanic populations.

Signs and Symptoms

Fatigue and weakness.
Swelling (oedema) in the ankles, feet, or hands.
Shortness of breath.
Nausea and vomiting.
Loss of appetite.
Changes in urine output and frequency.
Itchy skin.
Muscle cramps.
High blood pressure.

Investigations

Clinical history and physical examination.
Blood tests: Serum creatinine, estimated GFR (eGFR), urea, and electrolytes.
Urinalysis: To detect proteinuria, haematuria, and other abnormalities.
Imaging: Renal ultrasound to assess kidney size and structure.
Renal biopsy: In selected cases to determine the underlying cause of CKD.

Management

Primary Care Management

Monitoring of renal function and blood pressure.
Management of underlying conditions (e.g., diabetes, hypertension).
Lifestyle modifications: Encouraging a healthy diet, regular exercise, and smoking cessation.
Patient education on recognising symptoms and managing CKD.
Referral to a specialist (nephrologist) for further evaluation and management if CKD progresses or complications arise.

Specialist Management

Medications: To control blood pressure, blood sugar, and cholesterol levels.
ACE inhibitors or ARBs: To protect kidney function in patients with proteinuria.
Dialysis: For patients with end-stage renal disease (ESRD).
Kidney transplantation: For suitable candidates with ESRD.
Management of complications: Such as anaemia, mineral and bone disorders, and electrolyte imbalances.
Close monitoring: Regular follow-up to assess kidney function and manage any complications.

Example Management for Chronic Kidney Disease

A patient presenting with CKD should have their renal function and blood pressure regularly monitored. Management includes controlling blood sugar in diabetic patients, managing hypertension with ACE inhibitors or ARBs, and advising lifestyle changes such as a low-sodium diet, regular exercise, and smoking cessation. If CKD progresses to advanced stages, referral to a nephrologist is necessary for further evaluation and management, including potential dialysis or kidney transplantation. Regular follow-up is essential to monitor kidney function and manage any complications.

Stages of CKD

CKD is classified into five stages based on the estimated glomerular filtration rate (eGFR):

Stage 1: eGFR ≥90 ml/min/1.73m² (normal kidney function but with structural abnormalities or proteinuria).
Stage 2: eGFR 60-89 ml/min/1.73m² (mild reduction in kidney function).
Stage 3a: eGFR 45-59 ml/min/1.73m² (mild to moderate reduction in kidney function).
Stage 3b: eGFR 30-44 ml/min/1.73m² (moderate to severe reduction in kidney function).
Stage 4: eGFR 15-29 ml/min/1.73m² (severe reduction in kidney function).
Stage 5: eGFR <15 ml/min/1.73m² (kidney failure or end-stage renal disease).

References

NICE. (2024). Chronic Kidney Disease in Adults: Assessment and Management. Retrieved from NICE
NHS. (2023). Chronic Kidney Disease. Retrieved from NHS
National Kidney Foundation. (2021). KDOQI Clinical Practice Guideline for Nutrition in CKD. Kidney International Supplements.
Levey, A. S., et al. (2003). National Kidney Foundation Practice Guidelines for Chronic Kidney Disease: Evaluation, Classification, and Stratification. Annals of Internal Medicine.
Stevens, P. E., & Levin, A. (2013). Evaluation and Management of Chronic Kidney Disease: Synopsis of the Kidney Disease: Improving Global Outcomes 2012 Clinical Practice Guideline. Annals of Internal Medicine.