Chronic Kidney Disease Flashcards
What are people with CKD most likely to die from?
Cardiovascular events
CKD is defined as what 2 things?
Which determines the stage of the disease?
- kidney damage
- GFR less than 60 for more than 3 months
The GFR determines the stage and is the best assessment of overall kidney function
What is the gold standard for measuring GFR and why is it not used?
Inulin or iothalamate clearance is the gold standard but it is not used frequently because:
- it is an exogenous substance so you need to IV the patient to have them reach steady state
- It is expensive
What are the drawbacks of using CCr for measuring GFR?
What can it be averaged with to give a more accurate assessment of glomerular function?
- depends on muscle mass, race, gender, age
- tends to overetimate GFR in patients with kidney disease
- tends to underestimate in patients on trimethoprim (bactrim) and cinetidine
Average the CCr with the urea because Cr tends to overestimate and urea tends to underestimate.
What are the 2 equations that can estimate GFR bedside? Which is better to use in people with a GFR below 90?
- Cockcroft-Gault
- MDRD
They take into account ethnicity, gender, age, serum Cr
MDRD is better for patients with GFR below 90
What physical exam finding is a usual marker of kidney damage?
increased proteinuria
What is characteristic of stage 1 CKD?
- persistent proteinuria (>3 months)
2. normal or increased GFR (>90)
What is the preferred method for measuring proteinuria?
Total Protein to Cr ratio
or
Albumin to Creatinine ratio
These are both better than measuring timed urine collection (many errors)
What are the 5 stages of CKD?
1- persistent proteinuria with increased/normal GFR 2- kidney damage with GFR 60-89 3- GFR 30-59 4 - GFR 15-29 5- GFR <15
What stages of CKD should be treated by
- taking care of comorbid conditions
- intervening to slow progression
- reducing cardiovascular disease
What specific measures are taken?
Stages 1 and 2
Evaluate and treat BP by:
- block RAAS (ACEI/ARB)
- low protein diet
- control glucose
- treat hypercholesterolemia
What is the GFR cutoff for stage 3 CKD?
What should be evaluated and treated at this stage?
GFR 30-59
- anemia
- malnutrition
- bone disease
- neuropathy
- quality of life
What is the GFR cutoff for stage 4?
What treatment should take place at this stage?
15-29
Prepare for renal replacement therapy
What is the GFR for stage 5 CKD?
What should be evaluated and treated?
Evaluate uremia levels, look for dialysis options and kidney replacement.
When is it recommended to assess for kidney disease? How is the assessment performed?
ALL health encounters.
- calculate eGFR
- test for presence/absence of proteinuria
What happens to salt and water excretion per glomerulus and overall as the patient progresses in CKD?
The renal mass shrinks (less glomeruli) so the remaining glomeruli will increase filtration (hyper) in order to recover the loss of the other glomeruli.
This results in increased excretion per nephron but normal to slightly decreased Na/H20 excretion overall
What is the goal for salt balance in the diet of a patient with CKD?
What tells you if the salt intake is too low? too high?
A level of salt that keels the patient normotensive, at a constant weight with only slight edema
6-8 g/day is the starting point
Too low if the patient loses weight and becomes more azotemic
Too high if the patient gains weight and has edema and hypertension
When a patients GFR drops below 20, salt-restricted diets may exceed the capacity of the kidney to excrete. What should be added to the treatment regimen if this is the case?
Add a diuretic (specifically furosemide 2x daily)
Are people with CKD more likely to develop hypernatremia or hyponatremia?
What should fluid intake be for a person with CKD?
Equally because they lose the ability to concentrate AND dilute the urine as the kidney becomes progressively impaired.
Water intake should equal urine output plus 1000 to 1500 ml/day for insensible loss
How is a hyponatremic volume-overloaded patient be treated?
How should a hyponatremic, hypovolemic patient be treated?
Volume overloaded- restrict water intake
hypovolemic- water restriction with judicious addition of salt. Withdraw of diuretic
K balance is maintained until the GFR falls below what value?
What are the 2 ways it is able to maintain the balance?
10
- increase extrarenal excretion (colon)
- increase excretion via the remaining working nephrons
If there is hyperkalemia at a GFR above 10, what is the likely problem?
- TIN (type IV RTA)
2. RAAS disturbance
What is the initial treatment for someone with CKD that has developed hyperkalemia?
If after this and it persists, what would you treat the patient with if they were also:
- edematous/hypertensive
- acidotic
If STILL persisting, what do you add?
- K restricted diet (50-70mEq)
- If it persists:
Furosemide -esp if edematous or hypertensive bc increases distal delivery
NaHCO3 if acidotic (acid brings K out of cells, base pushes it back in) also, increases distal delivery (NRA) - If STILL persisting add K-binding resin (Na polystyrene) given with sorbitol to prevent constipation
As CKD progresses, patients develop metabolic acidosis. At first it is _______________ but as the insufficiency advances, it becomes ______________________________.
If left untreated, what can acidosis lead to?
NG ——-> acid gap
It can lead to:
- bone resorption
- protein catabolism
- dyspnea and malaise
What therapy must be provided to prevent the bone pathology associated with CKD?
What are complications?
Keep bicarb above 22 because the acidotic conditions are what really contribute to the bone resorption and protein catabolism.
NaHCO3 tablets – complications are:
- increased volume
- met alk
- aluminum with citrate absorption –>toxicity