mahoney

Question 1

Chronic renal failure (CRF)*****

Answer 1

• slow, relentless loss of functional renal mass
• GFR < 60ml/min for > or = to 3 months plus kidney damage
• primary causes = chronic glomerulonephritis, interstitial nephritis
• secondary causes = diabetes, hypertension

Question 2

pathology of kidney in chronic renal failure

Answer 2

• kidney reduced in size due to interstiital fibrosis and tubular loss
• Glomeruli are solidified and may become calcified
• Defect in Glomerular filtration of nitrogenous wastes –> ELEVATION OF SERUM BUN AND CREATININE
• Severe INTIMAL THICKENING IN LARGE AND SMALL RENAL ARTERIES
• multiple cyst formation (acquired cystic disease)
• Defect in tubular handling of water, electrolytes and trace metals (HYPERKALEMIA which leads to CARDIAC ARREST)

Question 3

Extrarenal manifestations **

Answer 3

• Gi tract = nausea and vomiting
• Anemia = due to decreased production of erythropoietin, decreased red cell survival
• Disturbances of blood coagulation = impaired platelet aggregation
• Hypertension = hypoperfusion of glomeruli or abnormal renal handling of salt and water

- Cardiovascular disease = due to hypertension, calcium deposition and hypertriglyceridemia

Question 4

why are triglycerides and LDL are increased in chronic kidney failure

Answer 4

• REduced lipoprotein lipase (possibly due to insulin deficiency or resistance mediated by vitamin D deficiency and presence of nondialyzable inhibitor of LPL)
• result in decrease in lelvels of nonartherogenic containing lipoproteins and increase in proatherogenic LDL and VLDL

Question 5

What are some more extrarenal manifestations

Answer 5

• lungs = chronic pulmonary edema
• Immune system = blunting of immune response
• Nervous system = disturbances in mentation, SENSORY AND MOTOR NEUROPATHY!!! (demyelination in peripheral nerves)

Question 6

What are the extrarenal manifesations in the parathyroid glands and bone due to chronic renal failure

Answer 6

• Parathyroid glands and bone

–> “turned on” due to HYPOCALCEMIA BROUGHT ABOUT BY RENAL RETENTION OF PHOSPHATE AND DECREASED INTESTINAL ABSORPTION OF CALCIUM due to imapired conversion of vitamine D to its active form

• Leads to secondary hyperparathyroidism, causing subperiosteal bone reabsorption priamrily in the tips of distal phalanges and clavicles, osteosclerosis and irregular radiolucencies with expansion of bone (BROWN CYSTS)

–> bone changes due to kidney disease known as RENAL OSTEODYSTROPHY (uremic bone disease)

Question 7

What are you going to see in the bones

Answer 7

• proliferation of osteoclasts and osteoblasts
• increased osteoblastic activity leads to elevation of alkaline phosphatase
• whole process leads to radiographic changes known as osteitis fibrosa cystica

Question 8

describe Renal osteodystrophy

Answer 8

• also known as uremic bone disease
• group of bone disorders seen in patients with CHRONIC RENAL FIALURE
• includes osteomalacia of adults and rickets of children, osteopenia, osteosclerosis, osteitis fibrosa cystica

Question 9

WHAT ARE BONE CHANGES BEROUGHT ABOUT BY: ***

Answer 9

1) abnormal metabolism of vitamin D
2) overproduction of PTH
3) chronic metabolic acidosis

Question 10

decreased vitamin D leads to…

Answer 10

decreased intestinal absorption of calcium –> hypocalcemia and defective bone mineralization

Question 11

renal retention of phsohate causes..

Answer 11

Hyperphosphatemia and further hypocalcemia, resutling in increased syntehsis and secretion of PTH

Question 12

result of metabolic acidosis

Answer 12

• also inhibits conversion ofa ctive form of vitamin D and increases solubility of bone mineral, further contributing to osteopenia

Question 13

what changes worsen as GFR decrease

Answer 13

• Hgb decrease and erythropoietin prduction is faulty
• calcium decreases
• vit D decreases
• ALbumin decreases

Question 14

need to know:*****

• Define chronic renal disease
• bone changes brought about by…
• extrarenal manifestations