Kanakiriya- CRF Flashcards
What is CKD?
kidney damage or
GFR<60 ml/min for greater than three months
What is kidney damage?
pathological abnormality in blood or urine tests or imaging studies
What are the primary causes of CKD?
Diabetes type 2 Diabetes type 1 HTN glomerulonephritis chronic interstitial nephritis and obstruction hereditary or cystic disease neoplasms or plasma cell dyscrasias
*70% d/t diabetes or HTN
What are the stages of CKD?
Kidney damage + (n) GFR >90 3.6m
Kidney damage + mild ↓ GFR 60-89 6.5m
Moderate ↓ GFR 30-59 15.5m
Severe ↓ GFR 15-29 0.7m
Kidney Failure <15 0.6m
How do you measure GFR?
Plasma creatinine Cystatin C Creatinine clearance (24hr urine) Estimated creatinine clearance (cockroft-gault formula) MDRD formula CKD-Epi formula
How do you measure plasma clearance?
isotopes- iothalamate
non-isotopes- iohexol
When is plasma creatine inaccurate? reduced? Raised?
Gold Standard- simple!
Inaccurate esp. with mild renal impairment
Reduced with LOW muscle mass
Raised with high protein meal
*affected by certain drugs
What is cystatin C? What is it not affected by? What is it affected by?
Low mol. Wt protein produced by all nucleated cells (will replace creatinine)
Not affected by diet, gender , age, muscle mass
Affected by steroids
What is the issue with creatinine clearance?
- Urine collections unreliable
- Overestimates GFR(tubular secretion of creatinine)
- Drug influences creatinine assays
What is used to estimate creatinine clearance?
Cockroft-Gault formula (gold standard)
140-Age x Wt (kg)/ 72 x S cr
What are the pros and cons of estimated creatinine clearance?
Avoids urine collection
More accurate than plasma creatinine especially with mild renal impairment
Overestimates in obesity & in low protein diet
Does impaired kidney function contribute to heart disease and CVA?
YES
What is considered to be the most accurate eqtn to calculate GFR?
CKD-EPI
What is plasma clearance?
Best approximation to true GFR
invasive
may use radioisotopes (most accurate)–
What do kidneys do?
excrete waste regulate/excrete water and solutes regulate AB status secrete EPO Ca, Phos, Vit D and bone metabolism
*1-1.3 million nephrons in each kidney
A pt has fatigue, type 1 DM since age 8. He also has a 3 year hx of HTN and a kidney problem. He has a high blood pressure, retinopathy, peripheral sensory neuropathy and trace peal edema and some crackles on auscultation. What does he have?
CKD
What are characteristic labs of a patient with CKD?
Low Hb/MCV High plasma Glucose elevated creatinine elevated K elevated CA Elevated Phosphorus Low bicarb (acidotic) Vit D (low) PTH (high) Proteinuria Elevated cholesterol elevated A1c
How do you manage CKD?
- Treat reversible causes of renal dysfunction (approach as if they have acute renal failure)
- Prevent or slow progression of renal disease
- Treat complication of renal dysfunction
- Preparation and initiation of renal replacement therapy
What are the reversible causes of renal dysfunction?
- decreased renal perfusion (pre-renal) –>Decreased fluids/dehydration/diarrhea/diuretic/vomiting/hypotension–too much BP medication
- Nephrotoxic drugs (MCC)- NSAIDS
- Urinary tract obstruction (post-renal)> prostate enlargement> relieve obstruction> kidneys get better (MC in men)
What slows the rate of progression of CKD?**
ACE inhibitors or/and ARBs Treat Hypertension (<7.0) Avoid nephrotoxic agents
Weight control--being overweight is hard on the kidneys!
Smoking cessation- nicotine associated glomeruluria
What can happen to creatinine when you start someone on an ACEi and ARB?
Upto 25% increase in creatinine can occur within 4 weeks
Higher increased in HF, volume depleted state and bilateral RAS
What should you monitor if you start someone on an ACEi and ARB?
*start w/ small dose and gradually increase the dose
Can cause hyperkalemia so should monitor creatinine and potassium
How do you treat complications of renal dysfunction?
Volume overload
Hyperkalemia
Metabolic acidosis
Hyperphosphatemia
Hyperparathyroidism (secondary)
AnemiaHow do you treat metabolic acidosis related to CKD? What are some of the negative affects of metabolic acidosis?
NaBicarbonate supplementation may slow progression of CKD (1-4/day depending on bicarb level)
Constant acidotic state can cause bone buffering and can worsen bone disease
Uremic Acidosis also leads to skeletal muscle breakdown and diminish albumin synthesis
How do you treat hyperphosphatemia related to CKD?
Dietary phosphorus restriction (800-1000 mg/day) (no milk, cheese, butter, nuts)
How much Na, K, Phosphorus should you have?
3, 2, 1
What should you do if a phosphorous restricted diet doesn’t work to treat hyperphosphatemia?
Phosphate binders
Calcium Carbonate (Tums) Calcium Acetate (Phoslo) Lanthanum carbonate (Fosrenal) Sevalamer (Renagel)
Calcium Citrate
Aluminum Hydroxide
Magnesium Hydroxide
What causes secondary hyperparathyroidism?
Increase in phosphorus>
decrease in Ca>
increase in PTH!
How do you treat secondary hyperparathyroidism?
Calcitriol (Rocaltrol)
Doxecalciferol (Hectoral)
Paricalcitol (Zemplar)
*Downside is that they make phosphorous and Ca go up. First want to get phosphorous down then treat PTH level.
Calcimimetic—Cinacalcet (Sensipar)
*Doesn’t make Ca or phosphorous go up but it’s expensive…bummer.
What are the steps for treating secondary hyperparathyroidism?
Correct Hyperphosphatemia first
Then treat sec. hyperparathyroidism with calcitriol or Vitamin D analogs
If hyperphosphatemia persists, consider Calcimimetics
Treat Vitamin D deficiency with either cholecalciferol or ergocalferol
How do you treat anemia caused by CKD?
Evaluation of anemia when Hb is <10g
RBC indices, retic count, iron, ferritin, transferrin saturation, stool for hemoccults
Treat iron deficiency ( IV Preferable)
ESAs : Procrit (erythropoetin) and Aranesp (Darbepoetin)
Target Hb 10-12 g
Caution with ESA use ( CV risk)
What do you do once kidney function is down to 20%?
Preparation and initiation of renal replacement therapy (RRT)
Hemodialysis (MC)
Peritoneal dialysis
Peritoneal dialysis
renal transplantation
What has high K?
fruits- bananas, oranges, potatos, tomatos, melons, prunes
