Chronic kidney failure Year 4 Internal Medicine Notes

Chronic kidney failure Year 4 · Internal Medicine Collection: 4TH YEAR ALL NOTES / IMED / IMED 4.2 / Mogere -- Slide 1 Chronic kidney failure Dr Alex Mogere Slide 3 Defn. Chronic renal failure (CRF) is X-terized by progressive destruction of renal mass and fxn due to irreversible sclerosis and loss of nephrons. CRF is reserved more specifically for patients whose GFR is less than 30 cc/min. Chronic renal insufficiency (CRI)- term for pts with mild-to-moderate renal impairment, whose GFR falls at 30-90 cc/min. End-stage renal disease (ESRD), usually with signs and symptoms of uremia, and GFR less than 10 cc/min. Slide 4 The Kidney Disease Outcomes -Quality Initiative (K/DOQI) classification of chronic kidney disease Stage 1: Kidney damage with normal or increased GFR ( 90 mL/min/1.73 m2) Stage 2: Mild reduction in GFR (60-89 mL/min) Stage 3: Moderate reduction in GFR (30-59 mL/min) Stage 4: Severe reduction in GFR (15-29 mL/min)-CRF Stage 5: ESRD (GFR <15 mL/min) Slide 5 Pathophysiology Abt. 1.2 million nephrons are present in each kidney, each contributing to the total GFR. The kidney has an innate ability to maintain GFR by hyperfiltration and compensatory hypertrophy of the remaining healthy nephrons. Urea and creatinine start to show significant increases only after total GFR has decreased to 50%. As the GFR falls to less than ~20% of normal, symptoms of uremia may begin to occur. Slide 6 Ct. Pathophysiology Nephron hyperfiltration and hypertrophy, although beneficial, may be a major cause of progressive renal dysfunction. This is due to increased glomerular capillary pressure, which damages the capillaries and leads initially to focal and segmental glomerulosclerosis and eventually to global glomerulosclerosis. Slide 7 Factors that may accelerate glomerular injury Systemic hypertension Acute insults from nephrotoxins or decreased perfusion Proteinuria Increased renal ammoniagenesis with interstitial injury Hyperlipidemia Hyperphosphatemia with calcium phosphate deposition Decreased levels of nitrous oxide Slide 8 Morbidity & Mortality The 5-year survival rate for a pt undergoing chronic dialysis approximately 35%. This is approximately 20% in pts with diabetes. Age: In US, the highest incidence of ESRD occurs in those older than 65 years. The elderly population also is the most rapidly growing ESRD population in the United States. NB After age 30 years progressive physiological glomerulosclerosis occurs, with GFR (and creatinine clearance [CrCl) falling linearly at a rate of approximately 8 cc/min/1.73 m2/year from a maximal GFR of 140 cc/min/1.73 m2. Slide 9 Ct. Morbidity & Mortality Aging also results in concomitant progressive physiological decrease in muscle mass such that daily urinary creatinine excretion also decreases;\nthis combination of factors results in constant serum creatinine values over time in a given individual, despite a decrease in CrCl (and GFR) Slide 10 Causes of chronic renal failure 1.Diabetic Nephropathy 2.Hypertensive nephropathy 3.Vascular disease Renal artery stenosis Cytoplasm pattern antineutrophil cytoplasmic antibody (C-ANCA)–positive vasculitides Perinuclear pattern antineutrophil cytoplasmic antibody (P-ANCA)–positive vasculitides Antineutrophil cytoplasmic antibody (ANCA)–negative vasculitides Hypertensive nephrosclerosis 4.Chronic Primary glomerular disease Membranous nephropathy Immunoglobulin A (IgA) nephropathy Focal and segmental glomerulosclerosis (FSGS) Minimal change disease Membranoproliferative glomerulonephritis rapidly progressive (crescentic) GN-RPGN Slide 11 Ct. Causes of chronic renal failure 5.Chronic Secondary glomerular disease Post infectious glomerulonephritis-endocarditis, hepatitis B and C, syphilis, HIV, parasitic infection, TB. amyloidosis, light chain deposition disease Neoplasm-lymphomas Thrombotic thrombocytopenic purpura (TTP) Hemolytic-uremic syndrome (HUS) Henoch-Schönlein purpura Alport syndrome Reflux nephropathy 6. Connective tissue diseases. Systemic lupus erythematosus Rheumatoid arthritis Mixed connective tissue disease Scleroderma Goodpasture syndrome Wegener granulomatosis Slide 12 Ct. Causes of renal failure 7. Tubulointerstitial disease Drugs (eg, sulfa, allopurinol), gold, penicillamine, Chronic NSAIDS Chronic infection (viral, bacterial, parasitic) Sjögren syndrome chronic hypokalemia chronic hypercalcemia Sarcoidosis Multiple myeloma cast nephropathy Heavy metals Radiation nephritis Cystinosis 8.Polycystic kidney disease 9. Urinary tract obstruction Urolithiasis, benign prostatic hypertrophy, tumors, retroperitoneal fibrosis, urethral stricture, neurogenic bladder Slide 13 Clinical presentation History: conspicuously absent in CRD, thus high index of suspicion is required. Pt may just complain of general fatigue, or just feeling ‘unwell’. Some pts may present with complaints related to the etiology-DM, Reflux disease,infections Many pts present with uraemic symptoms Slide 14 Ct. clinical presentation Of special importance in