09.2 Chronic Kidney Disease (CKD)

Chronic Kidney Disease (CKD)

• CKD is a significant global health issue affecting approximately 9% of the world's population.
• Characterized by structural and functional kidney abnormalities lasting more than three months.
• Often indicated by albuminuria or a glomerular filtration rate (GFR) below 60 mL/min.
• CKD progresses through five stages with increasing functional impairment and associated health problems.
• Early detection, classification, and management are essential for slowing disease progression and reducing cardiovascular risks.

Learning Objectives

• Understand the definition, classification, and staging of CKD.
• Identify and explain the causes of CKD.
• Recognize the symptoms, clinical signs, and complications of CKD.
• Outline the principles of CKD management, including investigations, treatment, and renal replacement therapies.
• Understand the prognosis and end-stage renal disease (ESRD) treatment options.

Key Concepts and Definitions

• Chronic Kidney Disease (CKD): Kidney abnormalities in structure or function (GFR < 60 mL/min) lasting more than three months.
• Glomerular Filtration Rate (GFR): Rate at which kidneys filter blood, used to classify CKD (stages G1 to G5).
• Albuminuria: Presence of albumin in the urine, indicating kidney damage.
• End-Stage Renal Disease (ESRD): Stage 5 CKD (GFR < 15 mL/min), often requiring renal replacement therapy.

Clinical Applications

• Case Study: 60-year-old diabetic and hypertensive patient with GFR 28 mL/min and albuminuria diagnosed with stage 4 CKD, treated with ACE inhibitors, dietary phosphorus restrictions, and erythropoietin.
• Diagnostic Approach: Screening (eGFR and albumin-creatinine ratio) is crucial for early detection, especially in high-risk groups (e.g., diabetes, hypertension).
• Treatment Options: ACE inhibitors, blood pressure control, glucose control, lipid management, and lifestyle changes to slow disease progression.
• Complications/Management: Managing anemia, mineral metabolism disorders, metabolic acidosis, and cardiovascular disease.

Pathophysiology

• Initial Damage: Nephron injury increases glomerular pressure, leading to basement membrane thickening and protein leakage.
• Compensatory Mechanism: Uninjured nephrons increase workload, resulting in glomerular sclerosis (scarring) and fibrosis.
• Progression: As damage increases, GFR declines, proteinuria worsens, and systemic complications emerge (e.g., hypertension, cardiovascular disease).

Pharmacology

• ACE Inhibitors: Reduce intraglomerular pressure and slow CKD progression (e.g., Enalapril, Lisinopril).
• ARBs: Used if ACE inhibitors are not tolerated.
• Erythropoiesis Stimulating Agents: Treat anemia due to reduced erythropoietin production (e.g., Epoetin, Darbepoetin).
• Phosphate Binders: Reduce serum phosphate to prevent secondary hyperparathyroidism (e.g., Sevelamer, Lanthanum Carbonate).
• Sodium Bicarbonate: Corrects metabolic acidosis and delays ESRD progression

Differential Diagnosis

• Diabetic Nephropathy: Distinguished by albuminuria and diabetic retinopathy.
• Hypertensive Nephropathy: Associated with long-term uncontrolled hypertension.
• Glomerulonephritis: Characterized by hematuria, proteinuria, and often a recent infection history.
• Polycystic Kidney Disease: Diagnosed with imaging which shows multiple kidney cysts.

Investigations

• Essential: eGFR, urea, electrolytes, FBC, urine microscopy and culture, albumin-creatinine ratio (ACR), calcium, phosphate, Vitamin D, HbA1c, and lipid profile.
• Additional: Renal ultrasound, X-ray abdomen, autoimmune profile, parathyroid hormone, CT scan abdomen, and renal biopsy.

Key Diagrams and Visuals

• Stages of CKD are described using GFR and ACR categories.

Summary and Key Takeaways

• CKD is a progressive disease categorized into 5 stages based on GFR and albuminuria.
• Diabetes and hypertension are common leading causes.
• Controlling those risk factors is critical to prevent progression.
• Complications include anaemia, bone and mineral metabolism disorders, metabolic acidosis, and cardiovascular disease.
• Renal replacement therapy (e.g., dialysis, transplantation) is crucial for ESRD.
• Management strategy includes ACE inhibitors, blood pressure control, cardiovascular risk management, diet, exercise, fluid balance, glucose control, and a healthy lifestyle.

This quiz provides an overview of Chronic Kidney Disease (CKD), including its definition, classification, symptoms, and management strategies. Participants will learn about the stages of CKD, its causes, and treatment options to improve prognosis and manage complications associated with the disease.