CKD and ESRD Flashcards
Define chronic kidney disease and end stage renal disease.
Chronic kidney disease is the progressive degeneration of the kidneys and loss of function over several months to years. End stage renal disease is a term used to describe a patient’s condition when renal failure has reached stage 5 (GFR < 15mL/min).
Differentiate the 5 stages of CKD based on kidney function (GFR).
Stage 1 = >90mL/min Stage 2 = 60-89 mL/min Stage 3 = 30-59 mL/min Stage 4 = 15-29 mL/min Stage 5 = <15 mL/min
Other than by GFR, what is one other method by which different levels of kidney disease can be differentiated?
albuminuria
A1= <30 mg/day A2= 30-300 mg/day A3= >300 mg/day
Explain how diuretic resistance develops and how it can be overcome.
Diuretic resistance often develops with long-term use of loop diuretics. As higher levels of sodium are continuously delivered to the DCT, sodium channels are working hard to accommodate by increasing reabsorption. Over time, DCT cells hypertrophy and express more sodium channels. This can eliminate the effect of the loop diuretic. To overcome this, the loop diuretic can be combined with a thiazide, which acts in the DCT.
What is the Cockroft-Gault equation, and what is it used for?
used for calculation of CrCl for drug dosing purposes and ESTIMATING kidney function
CrCl=((140-age)IBW)/(SCr72)
if female, multiply by 0.85
What is the MDRD equation, and what is it used for?
MDRD calculates GFR and is used for staging kidney disease.
If the Cockroft-Gault equation is going to be used for CrCl calculation, what must be true of the patient’s kidney function?
It must be STABLE. Patients with rapidly changing kidney function (those with AKI) cannot have CrCl estimated by this equation.
Explain why the Cockroft-Gault equation tends to overestimate kidney function in patients with moderate to severe kidney disease.
When GFR drops significantly, creatinine can still be disposed of, to an extent, by secretion to accommodate the loss of filtration. Our measured creatinine clearance would suggest that filtration is better than it actually is due to increased secretion.
When the kidneys cannot excrete metabolic wastes from the blood, the resulting condition is called ________.
uremia
What are some of the systemic effects of uremia? (hint: think about each body system and how it is affected by excess wastes or fluid)
CNS: encephalopathy
EENT: uremic fetor (pee breath)
pulmonary: non-cardiogenic edema from fluid overload
CV: Na retention–>volume overload–>LVH
GI: anorexia, constipation, metallic taste
musculoskeletal: restless leg syndrome and metabolic bone disorder
hemodynamic: anemia due to EPO deficiency
skin: uremic frost
Damaged kidneys cannot properly regulate the levels of ______ and ______ in the body, so patients are often fluid overloaded.
water and salt
What are the guidelines for fluid restriction in patients with fluid retention issues due to CKD?
Fluid restriction is not really necessary in these patients as long as their sodium intake is controlled. It is, however, recommended that these patients avoid large quantities of water.
Why don’t diuretics work in patients without functioning kidneys?
Diuretics work by increasing the amount of urine produced. If a patient can’t produce urine, the diuretic will have no effect.
________ diuretics will work when CrCl is <30 mL/min, but ________ diuretics will not.
Loop, thiazide
Why are thiazide diuretics less effective at very low CrCl levels? (<30 mL/min)
As CrCl gets below 30 mL/min, a greater percentage of sodium is reabsorbed in the PCT because there is less of it being filtered out and delivered to this segment. With more reabsorption in the PCT, there is less delivery to the DCT, where thiazides act. So, their effect is negated.
What are the dietary restrictions for sodium and potassium in patients with CKD?
NMT 2g of Na/day
NMT 5g of NaCl/day
NMT 3g of K/day
What is the treatment protocol for hyperkalemia?
will differ according to site, but usually involves:
- calcium chloride/gluconate to stabilize myocardium
- insulin/dextrose to push potassium back into cells
- nebulized albuterol
- potentially bicarb (but not for ESRD pts)
What are the 3 key points of mineral and bone disease that we can pharmacologically target?
(1) hyperphosphatemia
(2) hypocalcemia
(3) decreased vitamin D
What class of drugs is indicated for hyperphosphatemia? How do they work?
phosphate binders
They bind phosphate in the GI tract to prevent its absorption.
When MUST phosphate binders be taken, and why?
with meals, once phosphate has been absorbed in the blood, there is nothing we can do about it
What is the most common side effect of phosphate binders?
constipation
What is the maximum amount of elemental calcium that can be consumed per day?
1500 mg
calcium carbonate= _______
calcium acetate= _______
TUMS, PhosLo
Which calcium-containing phosphate binder binds more phosphate in the GI tract?
calcium acetate (PhosLo) – binds twice as much phos as TUMS
