Chronic Kidney Disease

Question 1

What is the definition of chronic kidney disease?

Answer 1

• Permanent reduction in glomerular filtration rate

* Usually under 60% is when you start saying there is kidney damage with lowered GFR

Question 2

What is stage FIVE of the CKD stages and what is the indicated treatment?

Answer 2

• Dialysis or transplant

* GFR is under 15 or the patient is on dialysis

Question 3

What is stage FOUR of the CKD stages and what is the indicated treatment?

Answer 3

• GFR is 15-29

* Treatment is prepare pt for renal replacement (dialysis)

Question 4

What is stage THREE of the CKD stages and what is the indicated treatment?

Answer 4

• GFR is 30-59

* Here you treat complications like fluids and electrolytes

Question 5

What is stage TWO of the CKD stages and what is the indicated treatment?

Answer 5

• 60-89 for GFR, and you just estimate progression

Question 6

What is stage one of the CKD stages and what is the indicated treatment?

Answer 6

• Under 90% GFR, diagnose what’s causing the damage and treat underlying cause

Question 7

When do symptoms that are directly related to CKD start appearing?

Answer 7

• Unfortunately when there is a ton of damage already
  
  • When GFR falls below 15ml/min/1.73m2
  • ESRD is end stage renal disease and that is when dialysis is needed to live

Question 8

What are the most common causes of Chronic Kidney Disease?

Answer 8

CKD is most commonly caused by Diabetic nephropathy

• hypertensive nephrosclerosis and renal vascular disease
• glomerulonephritis
• polycystic kidney disease
• interstitial nephritis
• obstruction

Question 9

What is the “intact nephron hypothesis”

Answer 9

CKD hypothesis that states nephrons functioning in diseased kidneys maintain glomerulotubular balance comparable to all other nephrons. filtration and net excretion are coordinated
*perhaps why GFR is so stinking decreased before azotemia signs are seen

Question 10

What is the “magnification phenomenon”?

Answer 10

In Chronic Kidney disease, the nephrons in the diseased kidney function homogenously.

• however, they alter their handling of given solutes as needed to maintain external balance if possible
• they magnify their excretion of a given solute to maintain balance

Question 11

what is meant by “individual solute control systems”?

Answer 11

Each solute appears to have a specific control system that is geared to maintain external balance in CKD
*each solute system has individual tubular handling and hormonal influences

Question 12

What is the “trade-off” hypothesis?

Answer 12

the mechanisms that are magnified in the diseased kidney to maintain individual solute control may have adverse effects on other systems.

• it’s like the body is choosing what to sacrifice to keep one system functioning over another
• increased parathyroid hormone secretion seen in CKD that helps maintain normal serum calcium and enhances renal phosphorus excretion, but it disturbes uric acid balance (sleep, sex, bone disease, anemia, lipidemia, vascular disease)

Question 13

How is the creatinine and urea balance handled in CKD?

Answer 13

• The rate of filtration is maintained for creatinine and urea at the expense of elevated plasma concentrations
  
  • Or, the excretion rates for urea and creatinine remain constant in the face of diminished clearance
  • Thus, creeping levels of BUN and creatinine are a good sign that GFR is diminishing and the kidneys aren’t too happy

Question 14

How is water balance handled in CKD?

Answer 14

• To maintain balance in a low GFR state, there must be a smaller fraction of water resorbed in CKD
  
  • The result is increased flow per nephron
  • As CKD is worse, water excretion is worse and pt. is hypoosmolality
  • Urine concentration is fixed around 300mOsm/kg water, leading to dehydration susceptibility
  • Prone to both hyper and hyponatremia due to water handling problems

Question 15

How is sodium balance handled in CKD?

Answer 15

• Fraction of sodium resorbed is decreased and fraction excreted is increased
  
  • Humoral natriuretic peptide helps incease sodium excretion in CKD
  • No ability to rapidly respond to sodium intake thus major increases can lead to edema
  • Also, extrarenal loss can more rapidly deplete total body sodium

Question 16

How is potassium balance handled in CKD?

Answer 16

• Potassium secretion and excretion in cortical collecting duct is increased in high tubular flow
  
  • Also increased potassium excretion in aldosterone rich circumstances with high sodium flow
  • Compensation in fecal loss is about 50% of normal daily load at maximum
  • Large potassium doses can make CKD patients hyperkalemic

Question 17

How is the H+ ion balance maintained in CKD?

Answer 17

• Functioning nephrons produce more NH4 to compensate for loss of nephron mass
  
  • 4-fold increase in NH4 keeps acid balance normal (traps H+ in urine) until GFR is around 25ml/min
  • As it gets worse there is chronic retention of H+, titrating down serum bicarb
  • Result is non-anion gap metabolic acidosis

Question 18

What are the three main factors that produce uremia?

Answer 18

• Retained metabolic products
○ Urea and other nitrogenous products play a role and their plasma concentrations are useful in assessing how well dialysis is working
○ No distinct relationship between these and the overall systemic process established
• Overproduction of counter-regulatory hormones
○ Overproduction of parathyroid hormone (response to hypocalcemia)
○ Also too much natriuretic hormone due to volume overload
• Underproduction of renal hormones
○ Decreased EPO and thus anemia
○ Decreased vitamin D processing leads to bone disease and secondary hyperparathyrodism

Question 19

What can uremia look like in terms of neurologic disorders?

Answer 19

Encephalopathy, peripheral neruopathy

Question 20

What can uremia look like in terms of hematological disorders?

Answer 20

• Anemia, bleeding propensity (platelet dysfunction)

Question 21

What can uremia look like in terms of cardiovascular disorders?

Answer 21

• Pericarditis, hypertension, congestive heart failure, CAD, vascular calcification

Question 22

What can uremia look like in Metabolic-Endocrine disorders?

Answer 22

glucose intolerance, hyperlipidemia, hyperuricemia, malnutrition, sexual dysfunction and infertility

Question 23

Bone, Calcium, and Phosphorus levels can be messed up in Uremia how?

Answer 23

hyperphosphatemia, hypocalcemia, dystrophic calcification, secondary hyperparathyroidism, Vitamin D deficiency, osteomalacia, osteitis fibrosa

Question 24

How can uremia affect the skin?

Answer 24

pruritis (itch), hyperpigmentation, easy bruising, purigo nodularis, uremic frost (ppt on skin from so much urea)

Question 25

uremia can present as which Psychological disorders?

Answer 25

depression and anxiety

Question 26

Uremia can cause what fluid and electrolyte disorders?

Answer 26

edema, hyponatremia, hyperkalemia, hypermagnesemia, metabolic acidosis, volume expansion or depletion

Question 27

Why is anemia a marker of CKD?

Answer 27

lack of EPO production, RBC life-span somehow is shorter in uremia, uremic patients bleed easily (especially in the gut), marrow space fibrosis occurs with the soteitis fibrosa of secondary hyperparathyrodism (complication of uremia)

Question 28

What hormone is increased in CKD that affects bone health as well as electrolyte balances?

Answer 28

Parathyroid hormone is released and elevated in CKD.
*regardless the reason, it results in elevated PTH, reduced levels of systemic calcium, and elevated serum phosphate levels

Question 29

in CKD, what important vitamin is unable to be fully processed?

Answer 29

Vitamin D. As GFR falls, renal production of 1,25 vitamin D falls.

• vitamin D normally stimulates teh absorption of calcium and phosphorus from teh intestine and down regulates PTH gene transcription
• the lack of the vitamin leads to decreased calcium levels overall and overproduction of PTH

Question 30

FGF-23 is an example of what and why is it important to CKD?

Answer 30

FGF-23 is a phosphotonin or a phosphorus regulatory hormone.

*released by bone to promote excretion of phosphorus and shut down 1,25 vitamin D production in the kidney

Question 31

What metal is particularly hard to dialyze out?

Answer 31

aluminum is not well eliminated by dialysis but is usually readily excreted by the kidney. Thus, dialysis patients can get aluminum toxicity

Question 32

The most studied evidence that once the kidney starts to fail it will end up totally failing is what phenomenon?

Answer 32

The combined over-compensation of the surviving nephrons (glomerular hyperfiltration and hypertension) that leads eventually to the death of these nephrons

Question 33

What does hypertension look like at the level of the single nephron?

Answer 33

the body is trying to increase GFR at the level of the single nephron (increase SNGFR). And since SNGFR is proportional to the hydrostatic pressure in the capillary, it dilates the afferent arteriole to allow a greater flow and pressure to increase that hydrostatic pressure.
*the increased pressure does eventually damage the nephron, partially explaining why CKD is a progressive disease

Question 34

What are the goals of dialysis?

Answer 34

remove toxins that are normally renally eliminated and to maintain the volume status of the patient
*it is a far cry from the actual kidney

Question 35

what are the two different types of dialysis?

Answer 35

hemodialysis (usually in the hospital) and peritoneal dialysis (usually at home)

Question 36

What are the initial indications for dialysis?

Answer 36

Severe conditions: severe hyperkalemia, volume overload or uremic pericarditis

Question 37

Is there a GFR cutoff for initiating dialysis?

Answer 37

No. though less than 10ml/min is a guaranteed symptom producer, it’s still not a mark for initiating dialysis

Question 38

How often and for how long to hemodialysis patients need to be in the dialysis center?

Answer 38

3X a week for 4 hours each time. This…sucks your life

Question 39

What is an AVF in the context of a CKD patient?

Answer 39

AVF is an arterio-venous fistula. A surgical connection of arterial and venous blood attached to a port for easier dialysis access.
*these mean this patient is in ESRD

Question 40

If a newly minted dialysis patient (just started this therapy) is feeling “off” what are you thinking?

Answer 40

Disequilibrium syndrome: headache, somnolence, seizures and sometimes coma

Question 41

What are the two types of peritoneal dialysis?

Answer 41

CAPD (continuous ambulatory, manual process) and CCPD (continuous cycling, it’s an automated process)

• both use a highly dextrosed dialysalate in the peritoneal cavity that sucks fluid from the blood into it, filtering kinda like the kidney
• mostly for fluid balance???