Chronic kidney disease and ESRD

Question 1

CKD

Answer 1

-A decrement in GFR <15

Question 2

Risk factors of CKD

Answer 2

• Most important cause of CKD is diabetes
• Proteinuria
• HTN: goal for BP isnt as large of a risk factor w/o proteinuria
• But w/ proteinuria HTN is a substantial negative risk factor

Question 3

Rx of CKD and prevention

Answer 3

• Rx the underlying cause of the disease

- This includes giving ACEIs/ARBs, statins for hyperlipidemia

Question 4

Complications of CKD

Answer 4

• Metabolic derangements
• CV complications
• CKD mineral bone d/o
• Anemia, platelet dyfxn
• Metabolic complications arise as GFR declines and excretion of certain solutes declines as well
• Impaired excretion of: Na, K, PO4, H+, uric acid
• Also impaired urinary dilution and concentration

Question 5

Clinical manifestations and lab findings

Answer 5

• Manifestations: fatigue, weakness, pruritus, pallor, anorexia, nausea, vomiting, insomnia, irritability, confusion, hyperreflexia, dyspnea, edema, pericarditis
• Labs: metabolic acidosis, hyperphosphatemia, hypocalcemia, hyperkalemia, anemia, hyperuricemia, broad waxy casts

Question 6

CVD complications from CKD

Answer 6

• IHD: accelerated atherosclerosis
• HF: chronic volume overload, vascular calcification, cardiac ischemia
• Arrhythmias: cardiac remodeling + metabolic derangements

Question 7

CKD mineral bone d/o (secondary hyperparathyroidism)

Answer 7

• PTH levels rise in CKD due to the combination of: decreased vit D, hyperphosphatemia, hypocalcemia
• Hypocalcemia (due to low levels of vit D- made in PT) leads to increase in PTH release (PTH increases bone turnover to release Ca and PO4 into blood)
• W/ declining GFR excretion of PO4 decreases
• High PO4 levels further stimulate PTH and increases FGF23 levels to increase renal PO4 excretion
• The kidney, however, cannot excrete the PO4 appropriately so PO4 levels remain high
• FGF23 also normally inhibits PTH release, however in the setting of CKD there is both high FGF23 and PTH thus the parathyroids become resistant to the FGF23

Question 8

Bone d/o in CKD

Answer 8

• Osteitis fibrosa cystica: high bone turnover w/ increased PTH
• Increased osteoclast activity causes an irregular woven collagen matrix thats weak
• Adynamic bone: low bone turnover, w/ low PTH
• Overall little bone formation

Question 9

Management of secondary hyperparathyroidism

Answer 9

• Restrict PO4 in diet
• PO4 binders w/ meals
• Screen for vit D deficiency and Rx
• Monitor PTH, correct hypocalcemia

Question 10

Anemia of CKD

Answer 10

• EPO deficiency: normocytic anemia
• Anemia more prevalent when GFR <30
• CKD pts have impaired Fe absorption (mediated by hepcidin)
• Can give EPO, but has adverse effects: HTN, stroke, thrombosis, RBC aplasia, Fe deficiency, malignancies

Question 11

Rx options for ESRD

Answer 11

• Hemodialysis or peritoneal dialysis
• Principles of Rx: solute clearance and volume removal
• Primary mechanism of solute removal is diffusion
• Primary mechanism of fluid removal is hydrostatic pressure
• Diffusion is used to achieve desired electrolyte concentrations (i.e. can give back Ca by using a high Ca dialysate)
• Peritoneal dialysis: blood is filtered indirectly (peritoneal membrane is filter
• Diffusion occurs btwn blood in the capillaries of the peritoneal membrane and dialysate in the peritoneum