Chronic Kidney Disease (CKD) Lecture PDF

Chronic Kidney Disease (CKD) Lecture Number 9.2 Status Done Type Lecture 9.2 Chronic Kidney Disease (CKD) Overview Chronic Kidney Disease (CKD) is a significant global health issue affecting approximately 9% of the world’s population. The disease is characteri...

Chronic Kidney Disease (CKD) Lecture Number 9.2 Status Done Type Lecture 9.2 Chronic Kidney Disease (CKD) Overview Chronic Kidney Disease (CKD) is a significant global health issue affecting approximately 9% of the world’s population. The disease is characterized by structural and functional abnormalities of the kidneys lasting more than three months, often indicated by the presence of albuminuria or a glomerular filtration rate (GFR) below 60 mL/min. CKD progresses through five stages, each with varying degrees of functional impairment and associated health complications. Early detection, classification, and management are crucial for slowing disease progression and reducing associated cardiovascular risks and mortality. Learning Objectives Objective 1: Understand the definition, classification, and staging of CKD. Objective 2: Identify and explain the etiopathogenesis of CKD. Objective 3: Recognize the symptoms, clinical signs, and complications of CKD. Objective 4: Outline the principles of CKD management, including investigations, treatment, and renal replacement therapies. Objective 5: Understand the prognosis and end-stage renal disease (ESRD) treatment options. Key Concepts and Definitions Chronic Kidney Disease (CKD): Defined as abnormalities in kidney structure or function (GFR < 60 mL/min) persisting for more than 3 months. Glomerular Filtration Rate (GFR): The rate at which the kidneys filter blood, essential for classifying CKD into five stages (G1 to G5). Albuminuria: The presence of albumin in the urine, a key indicator of kidney damage. End-Stage Renal Disease (ESRD): Stage 5 CKD, marked by GFR < 15 mL/min, often requiring renal replacement therapy. Clinical Applications Case Study: A 60-year-old man with diabetes and hypertension is found to have a GFR of 28 mL/min and albuminuria on routine screening. He is diagnosed with stage 4 CKD and is started on ACE inhibitors, dietary phosphorus restrictions, and erythropoietin for anemia. Diagnostic Approach: Screening for CKD using eGFR and albumin-creatinine ratio (ACR) is essential for early detection, especially in high-risk groups (e.g., diabetes, hypertension). Treatment Options: ACE inhibitors, blood pressure control, glycemic control, lipid management, and lifestyle changes to slow progression. Complications/Management: Manage complications such as anemia, mineral metabolism disorders, metabolic acidosis, and cardiovascular disease. Pathophysiology Initial Damage: Injury to the nephron increases glomerular pressure, causing basement membrane thickening and protein leakage. Compensatory Mechanism : Uninjured nephrons increase their workload, but over time, this leads to glomerular sclerosis and fibrosis.  Progression : As damage increases, filtration declines, proteinuria worsens, and systemic complications like hypertension and cardiovascular disease emerge. Pharmacology ACE Inhibitors (e.g., Enalapril, Lisinopril): Reduce intraglomerular pressure, slow CKD progression. Angiotensin II Receptor Blockers (ARBs): Used if ACE inhibitors are not tolerated. Erythropoiesis-Stimulating Agents (e.g., Epoetin, Darbepoetin): Used to treat anemia caused by reduced erythropoietin production. Phosphate Binders (e.g., Sevelamer, Lanthanum Carbonate): Reduce serum phosphate levels to prevent secondary hyperparathyroidism. Sodium Bicarbonate: Corrects metabolic acidosis, delays ESRD progression. Differential Diagnosis Diabetic Nephropathy: Distinguished by albuminuria and diabetic retinopathy. Hypertensive Nephropathy: Associated with long-standing uncontrolled hypertension. Glomerulonephritis: Presents with hematuria, proteinuria, and often a recent history of infection. Polycystic Kidney Disease: Diagnosed via imaging revealing multiple kidney cysts. Investigations Essential: eGFR, Urea, and Electrolytes Full Blood Count (FBC) Urine Microscopy and Culture Albumin-Creatinine Ratio (ACR) Calcium, Phosphate, and Vitamin D levels Hemoglobin A1c and Lipid Profile (for diabetes and cardiovascular risk) Additional: Renal Ultrasound (for polycystic kidney disease) X-ray Abdomen (to detect renal stones) Autoimmune Profile (for suspected glomerulonephritis) Parathyroid Hormone (to detect secondary hyperparathyroidism) CT Scan Abdomen (for malignancy or obstruction) Renal Biopsy (for atypical presentations) Key Diagrams and Visuals Summary and Key Takeaways Takeaway 1: CKD is a progressive disease classified into 5 stages using GFR and albuminuria. Takeaway 2: Diabetes and hypertension are the leading causes of CKD, and controlling these risk factors is essential to prevent progression. Takeaway 3: Complications of CKD include anaemia, bone and mineral metabolism disorders, metabolic acidosis, and cardiovascular disease. Takeaway 4: Renal replacement therapy (RRT) is essential for ESRD, with options including peritoneal dialysis, haemodialysis, and renal transplantation. Takeaway 5: Management follows the "A, B, C, D, E, F, G, H" strategy: ACE inhibitors, Blood pressure control, Cardiovascular risk management, Diet, Exercise, Fluid balance, Glucose control, and a Healthy lifestyle. Further Reading/References Resource 1: KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Resource 2: "Chronic Kidney Disease" - The Lancet, February 2020. Questions/Clarifications Question 1: How does ACE inhibitor therapy affect GFR, and why is it beneficial for CKD? Question 2: Why is the albumin-creatinine ratio (ACR) a more useful diagnostic tool than 24-hour urinary protein collection? Question 3: What are the indications for initiating renal replacement therapy in CKD?