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
