Chronic Kidney Disease Flashcards
How to measure flow rates in the kidney
GFR of the kidney
- this is the value used to determine chronic kidney disease for certain
Why is creatinine not the best determinant of GFR?
Creatinine can be influenced very easily by muscle mass, increased/decreased meat intake and age
it is still good to use, just not by itself
Proteinuria
Protein/albumin in urine usually Caused by glomerular hypertension
In chronic kidney disease, the quantity of proteinuria is strongly correlated to mortality rates
What are the top 3 casues of CKD in the US?
Hypertension
Diabetes
Acute kidney injuries (severe acute episodes or repeated mild acute kidney injuries)
Pre-renal causes of AKI
Hypovolemic states
- hypotension
- acute hemorrhage
- diarrhea
Congestive Heart Failure (CHF)
- **seems counterintuitive since CHF leads to hypervolemia and edema, however actually causes intravascular hypovolemia and decreased kidney perfusion
Vascular alterations limiting glomerular flow
- overuse of NSAIDs
- constricts the glomerular afferent arteriole
- overuse of ACEi’s/ARBs
- dilates efferent > afferent. = lower GFR
- use of radiocontrast
- constrict afferent arteriole
Intrinsic renal causes of AKI
Glomerular diseases
- nephrotic and nephritic syndromes
Acute tubular necrosis
- ischemia and exposure to nephrotoxicity
Acute interstital nephritis
- mostly by overuse of medications
Renal vascular diseases
- TTP/HUS/polyangitis/ thrombosis
Post renal causes of AKI
Any obstruction of the urinary tract that blocks urinary flow
- prostate cancer and benign prostate Hypertrophy are the most common
- kidney stones are next
Treatment of CKD
1st step is always to identify and treat any underlying causes
- usually diabetes and HTN
- stop nephrotoxicity medications
2nd step is to protect the nephrons (these dont regenerate)
- avoid any causes of decreased kidney perfusion. Includes hypovolemia, hypotension, GFR-lowering drugs (DONT over treat HTN and avoid NSAIDs)
- also avoid very high doses of ACEi/ARBs as best as possible (they do still provide benefits in step 3 however)
- avoid radioconstrast dyes
3rd step is to include protective measures
- prevents excess increases in intraglomerular pressure
- this includes use of ACEi/ARB in low doses (dilates efferent arterioles and lowers glomerular pressures)
- also stop smoking, restrict proteins in diet and treat metabolic acidosis if it arises
What is the #1 ADR to watch for in CKD patients who are started on ACEi/ARB
Hyperkalemia
- if this occurs need to stop the ACEi/ARB
Complications of CKD and treatments
1) Metabolic acidosis
- bicaronate supplementation with careful monitoring
2) Volume overload
- restrict sodium
- diuretics (usually loop)
- compression stockings
3) hyperkalemia
- restrict potassium
- AVOID NSAIDs and ACE/ARBs if present
4) bone and mineral disorders (usually hyperphosphatemia)
- restrict phosphate
- vitamin D3 supplementation
5) hypertension
- loop diuretic or ACEi/ARB (use clinical judgement)
- need to try to get BP to 120-130/<80
6) anemia
- give erythropoietin supplements
7) dyslipidmeia and sexual dysfunction
- give statins and drugs for sexual dysfunction as long as it is medically safe to do
What is the time cut off between acute vs chronic kidney disease?
3 months
- less than 3 months = Acute
- greater than 3 months = chronic
How to treat complications of renal disease
Volume overload
- sodium
- diuretics (usually loop and need to be careful with dosing)
- compression stockings
Hyperkalemia
- low potassium diet
- avoid NSAIDs and ACEi/ARB is hyperkalemia is high.
Metabolic acidosis
- bicarbonate supplements
Bone and mineral disorders
- Dietary phosphate restriction
- phosphate binders
- vitamin D3 supplementation
HTN
- loop diuretics and ACEi/ARB (be careful with hyperkalmei)
Anemia = erythropoietin
