Renal - to final Flashcards
Hemodialysis
filtration process via semipermeable membrane, used to eliminate toxins from the blood stream
* need to perform surgery to make fistula (for access to blood)
Causes of End-stage kidney disease
- Diabetes
- HTN *usually not biopsied.
- Glomerulonephritis (esp. IgA)
- Interstitial Nephritis (esp. from meds)
- PCKD/Alport’s
- ATN (acute tubular necrosis, rare)
Why is risk for end stage renal disease greater in African Americans?
*1. genetic: G1 or G2 variants of Apo-L1 gene
(increase risk 40% if 1 copy, 60% if 2 copies)
2. higher risk for other diseases (DM, HTN)
3. inadequate medical care (poor)
Why are fistulas preferred to catheters for dialysis port?
catheters have higher need for anticoagulation, and higher risk of infection.
(vs. much less in arm fistula)
What is removed or not by dialysis?
Removed: small ions (Na+, K+, Ca2+, Mg2+), Lithium
* water: removed proportionately to permeability (# pores) of dialysis membrane
NOT removed: blood, protein, high MW proteins
4 Renal Heroes:
- Bud Rose
- Peter Agre
- Willem Kolff (invented first dialysis machine)
- Steve Jobs (made organ donation an opt OUT process in California)
Complications of dialysis
- hypotension
- bleeding
- dialysis disequilibrium (bc electrolytes off, not so much now)
- bacteremia/sepsis
- AV fistula thrombosis/intravascular clots from catheters
normal GFR for healthy person (avg)
normal GFR = 100 ml/min
Problems assoc. w/ dialysis & mortality
1. MI/cardiovascular disease
- hypertension BEFORE dialysis procedure - lipids (low HDL, high TGs) 2. infection 3. amputations 4. anemia (bc low EPO)
Transplant vs. Dialysis
transplants recipients have lower relative risk of death
* harder/takes longer to get transplant (have to wait on list)
BUT do have similar associated medical problems as dialysis
Medical problems improved with kidney transplantation
Will stabilize: Ca deposition, renal osteodystrophy
Will improve: malnutrition, depression, anemia, myopathy, LV dysf(x), energy level
Medical problems that continue/are associated with kidney transplants
Ongoing: HTN, atherosclerosis
New: Malignancy (esp. skin cancer), DM (new onset/worse control), opportunistic infections
Chronic Kidney Disease
Kidney damage, w/ GFR < 60 for at least 3 months. 5 stages – 1 = normal GFR, 5 = dialysis.
(“kidney damage” can be IDed w/ blood/urine tests or imaging)
Causes of Chronic Kidney Disease (not necessarily end-stage)
- Diabetes (50%)
- HTN
- Glomerulonephritis
- Polycystic Kidney Disease
- Failed transplants
Association btwn retinopathy and nephropathy in diabetics
DM1: almost ALL pts w/ nephropathy have retinopathy also.
(but more DM1 have retinopathy than nephropathy)
DM2: 75% w/ nephrop. also have retinopathy
==> if DM2 & retinopathy, VERY VERY likely to have nephropathy.
Mechanism of chronic kidney disease from diabetes
- loss of some/many nephrons
- remaining nephrons compensate –> intraglomerular pressure rises
- more renal damage bc high P
effect of blood pressure on renal function
maintainting systolic BP < 140 –> postpone prorgession to dialysis by 16 years! AND reduce risk CV/other complications too!
*even better than controlling glycemic levels!
role of diabetes control in preventing kidney disease
NO evidence that glycemic control alone slows CKD directly, but does decrease proteinuria.
CAN get protection and Regression (!) of diabetic kidney lesions after pancreatic transplant!
Treatments most helpful in preventing kidney disease progression
- anti-hypertensives
- ACE Is or ARBs (but NOT both)
- control glycemia in diabetics
- HCO3 supplementation (slows progression by 50%!)
Lifestyle changes to help prevent renal disease progression
- lowering lipids
- smoking cessation
* Conflicting evidence on protein and salt intake
Symptoms of anemia
LV dysfunction, sleep impairment, poor exercise tolerance, sexual dysfunction
* can treat w/ EPO but has heart risks
Fetuins
powerful inhibitors of hydroxyapaptite formation,
often low w/ renal failure ==> exess arterial/valve calcifications & weak bones
* Tx: phosphate control, calcitrol (VitD) supplementation, calcimimetics (–> suppress PTH)
5 causes of acidosis WITH abnormal anion gap
- Lactic acid
- Ketoacids
- Organic acids (accumulate in renal failure)
- Toxins (methanol, ethylene glycol, salycilate)
- Rhabdomyolysis
2 causes of non-anion gap acidosis
- Diarrhea
2. Renal Tubular Acidosis
3 types of renal tubular acidosis (RTA)
type I: Distal, decreased H+ excretion –> pH >5.3 (Sjogrens, amphotericin)
type II: Proximal, decreased HCO3- reabsorption –> LOW K, pH HIGH K
3 steps in nephrolithiasis
- form nidus (oversaturation or supersaturation)
- retain nidus *higher risk if have “randall plaques”
- nidus GROWTH
Risk factors for Calcium stones
1. hypercalciuria (hyperPTH, type 1 RTA, sarcoidosis, GI malabsorption)
- hypocitraturia *bc citrate –l stones
- hyperuricosuria (uric acid in urine)
- hyperoxaluria
- low urine volume
risk factors for Uric acid stones
1. acidic urine!! (pH = 5, constant)
- uricosuria (gout, chronic diarrhea, myeloproliferative disorders, DM2)
- low urine volume
risk factors for cystine stones
- high cystine excretion (*kids often have low renal cystine transport)
- acidic urine
- low urine volume
Risk factors for infectious stones
- urease-producing bacteria
- alkaline urine
- urine NH3
Causes of acute kidney injury
- prerenal (low renal blood flow)
- renal –> ATN, AIN, acute GN, cholesterol emboli
- post-renal (obstruction)
ATN: tubular necrosis, AIN: interstitial nephritis, GN: glomerulonephritis
