Chronic Kidney Disease Flashcards
What are the primary functions of the kidneys?
- filter waste from the bloodstream
- reabsorbs everything the body needs
- maintain fluid, electrolyte and acid-base balance
what are the secondary functions of the kidney?
- helps regulate BP
- activates vitamin D so it can absorb calcium from GI tract
- produce a substance called erythropoietin that acts on bone marrow to produce RBCs
what is the functional unit of a kidney called? how many of these units does a kidney have?
a nephron, each kidney has about 1 million
explain chronic kidney disease (CKD)
- involves the progressive, irreversible destruction of nephrons in both kidneys
- is related to kidney damage or renal insufficiency that is present for 3 months or longer
- usually develops over months/years
how is CKD classified?
CKD is classified at one of 5 stages based on the severity which is based on glomerular filtration rate
what are the risk factors for CKD?
hypertension, smoking, diabetes, and aging
- Hypertension is both a cause and an affect of CKD
what is the glomerular filtration rate?
- the amount of blood filtered by glomeruli in a given time mls/min
- is affected by age, gender and muscle mass
how does the GFR decrease after the age of 30?
the GFR decreases by 1ml/year after 30
what is the estimated glomerular filtration rate (eGFR)?
the eGFR is a mathematical equation used to determine the stage of kidney disease and how well they are working.
- it is used clinically and helps decide if meds need to be changed and how often meds need to be given
what is the best overall index of renal function?
60 mls/min a minute or greater. if it is less than 60mls/min it is defined as CDK
what is stage 5 of CKD?
stage 5 is end-stage renal disease. it is advanced kidney disease with a GFR of less than 15mls/min
how much urine is made from what the kidneys filter?
for every 125mls filtered, only 1ml of urine is made
what is creatinine?
a waste product of muscle and protein breakdown
what is uremia?
uremia is a constellation of signs and symptoms resulting from the buildup of waste products and excess fluid associated with kidney failure
what are the signs and symptoms of uremia?
- elevated serum creatinine and blood urea nitrogen, abnormal electrolytes, acidosis, anemia, fluid volume excess, nausea, loss of appetite, fatigue, decreased cognition, pruritus and neuropathy
what are the goals of treatment?
- modifying risk factors, avoiding nephrotoxic substances, being careful with NSAIDs, protect existing kidney function, correct anemia
why do you need to be careful with NSAIDs when it comes to CKD?
because NSAIDs block synthesis of prostaglandins which cause vasodilation. this causes blood vessels to constrict increasing BP
- increased BP is a cause of CKD
how can you correct anemia in a patient with CKD?
- use meds like erythropoietin (eprex) or darbepoetin alfa (aranesp)
- monitor Hgb and BP
- use iron supplements like folic acid or ferrous sulfate
how do you correct fluid volume overload?
- add all the losses from the previous 24 hours and then add 600 ml to this of insensible losses
why may some patients with diabetes who are uremic require less insulin after the onset of CKD?
because since insulin is dependant on the kidneys for excretion, it remains in the circulation longer
why are bones at risk with CKD?
as kidney function declines, phosphorus elimination decreases and less vitamin D is converted to its active form. this lowers serum levels.
- activated vitamin D is needed to absorb calcium from the GI tract
what happens when hypocalcemia occurs?
the parathyroid gland secretes PTH and this stimulates bone demineralization with the release of calcium from the bones.
what do you use to treat elevated phosphorus (hyperphosphatemia)
give phosphate binders with meals and restrict phosphorus in diet by limiting dairy products
why are those with CKD at risk for fractures?
because the parathyroid gland releases hormones that pulls calcium from bones which makes them weaker
what does hyperphosphatemia, decreased vitamin D levels and hypocalcemia lead too?
they lead to overstimulation of the parathyroid glands, resulting in excess secretion of PTH and if PTH levels remain elevated for a long time it can lead to hypertrophy of the glands and bone disease
how is hyperkalemia treated with meds?
treatment with IV glucose and insulin or beta-adrenergic agonists such as salbutamol which shifts potassium into the cells
what medications are used to treat hypertension in CKD?
- it is treated with diuretics such as furosemide which increases renal excretion of water, sodium, chloride, magnesium, potassium and calcium.
- also use beta-blockers like metoprolol and calcium channel blockers like nifedipine (adalat) and ACE inhibitors such as ramipril
why must ACE inhibitors such as ramipril and ARBs be used cautiously in CKD patients?
because they can further decrease the GFR and increase serum potassium levels
what are some potential assessment findings you’ll see in a CKD patient?
- altered cognitive ability & concentration
- fatigue, headache, cold intolerance
- metallic or off taste
- hypertension
- dyspnea, palpation, angine
- nocturia
why are CKD patients at risk for drug toxicity?
because many drugs are either partially or totally excreted by the kidneys, delayed or decreased elimination leads to an accumulation of the drugs in the body
what are some examples of high potassium foods?
avocados, bananas, carrots, mushrooms, chicken, chocolate, sunflower seeds
examples of CKD nursing diagnosis
- excess fluid volume r/t excessive fluid intake
- impaired electrolyte imbalance AEB excessive fluid volume
- imbalanced nutrition r/t insufficient dietary intake
what is dialysis?
dialysis is a technique where substances move from the blood through a semipermeable membrane (dialyzer) and into a dialysis solution
why is dialysis used?
it is used to correct fluid and electrolyte balance and to remove waste products in renal failure
when is dialysis needed?
needed when there is volume overload, hyperkalemia, metabolic acidosis, decreased in eGFR, increased serum creatinine and BUN and changes in mental status
what is peritoneal dialysis?
- it is the method of removing waste products and excess fluid from the blood using a natural semipermeable membrane, the peritoneal
- a catheter is in the abdomen and hooked to long bags of fluid with varying concentrations of glucose
what are some complications of peritoneal dialysis?
exit site, infection, peritonitis, abdominal pain, outflow problems, hernias, lower back problems, bleeding, protein loss
what is hemodialysis?
- in hemodialysis waste products and excess fluid are removed from the blood using a machine to pump the blood through an artificial semipermeable membrane
what is required for hemodialysis treatment?
vascular access arterial-venous (A-V) fistula, dialyzer and dialysate
when is dialysis initiated?
when the GFR is less than 15ml/min.
- when patients symptoms, fluid volume status, or both can longer be managed with dialysis
what is diffusion?
the movement of solutes from an area of greater concentration to an area of lesser concentration
what is osmosis?
movement of fluid from an area of lesser to an area of higher concentration of solutes
what is ultrafiltration (water & fluid removal)
results when there is an osmotic gradient or pressure gradient across the membrane
what are the 3 phases of peritoneal dialysis?
- inflow (fill)
- dwell (equilibration)
- drain
what are the advantages of kidney transplantation?
- when normal kidney function is restored, many of the pathophysiological changes associated with renal failure are reversed
- also eliminates the dependence of dialysis, dietary and lifestyle restricitons
what is the required age of a kidney donor? can they be alive or deceased?
age of donor can be between 2-70, their health is considered.
- donors can be either deceased or live
