Week 10 CKD Kidney disease patho Flashcards
ESRD (end stage renal disease) signs - uremia
- Fluid retention
- electrolyte imbalance
- waste product accumulation
- hormone insufficiency
- Increase in blood lipoproteins (LDL) (increases CVD)
- Changes in bone metabolism
What is the best indicator of kidney function ?
eGFR (estimated GFR)
What is the best blood values to detect CKD?
Urea and creatinine
When do we know someone has a CKD diagnosis?
When GFR is <60ml/min for >3 months (stage 3)
What is the leading cause of death in patients with CKD?
Cardiovascular disease CVD
Patients with Uremia will develop what related to the increase in triglycerides?
Dyslipidemia (altered LDL and HDL)
Why do people with CKD experience increased levels of LDL?
The enzymes needed to breakdown LDL are impaired.
What symptom is prevalent in CKD and why?
Puritis
due to calcification
What is it called when blood urea/nitrogen levels are extremely high and where is it seen?
Uremic frost
crystalizes on the skin
Why are people with CKD prone to ecchymosis?
Because of decreased platelet function due to increased uremia.
What is the GFR rate?
125ml/min
How much urine is normally formed per day?
1-3 L of urine
What structure carries filtrate to the bladder?
ureters
What three forces control GFR?
- hydrostatic pressure (BP) - in artery - pushes out against artery walls
- Colloid osmotic pressure (pull from proteins, mostly albumin) - pulls fluid into blood stream
- Capsular hydrostatic pressure (from tubules to glomerulus) - pushes against artery wall outside in
What are fenestrations?
like a filter screen that allow small particles to pass into filtrate
Why does albumin not pass through glomerulus?
negative charge of basement membrane
What is the cause of messed up filtration within the glomerulus?
inflammation
What collects glomerular filtrate and funnels it into the tubule?
Bowman’s capsule
What do the proximal convoluted tubule and Loop of henle absorb?
reabsorbs:
1. sodium
2. chloride
3. water
4. glucose
5. amino acids
6. potassium
7. calcium
8. bicarb
9. phosphate
10. urea
What does the Distal convoluted tuble do?
absorbs:
1. all the electrolyte nutrients
2. bicarb
secretes:
1. potassium
2. hydrogen
where is the receptor site for antidiuretic hormone (ADH) and vasopression for the regulation of water balance?
Collecting duct
how is GFR reduced in the nephron and why does it work that way?
afferent arteriole - constriction
efferent arteriole- dilation
- if you constrict what is coming in and let what is in there flow out quickly then you reduce how much blood is being filtered.
how is GFR increased in the nephron and why does it work that way?
afferent arteriole - dilation
efferent arteriole- constriction
- if you dilate what is coming in and lessen what is leaving, then you have more blood to be filtered
Which filtration pressure is most important for maintaining kidney function?
Hydrostatic pressure (BP)
What are the 3 Primary Functions does the kidney do?
- Fluid & electrolyte balance
- Acid- base balance
- Filter & excrete waste from blood
What are the 3 secondary functions of the Kidney?
- RAAS
- produce erythropoietin - stimulates RBC production during hypoxia
- Activate vitamin D - to help absorb dietary calcium
Where is renin secreted from?
juxtaglomerular nephron
What 5 events stimulate renin to be released?
- low BP (pressure) - hypotension
- low blood volume aka renal perfusion- hypovolemia
- low sodium in blood - hyponatremia
- high sodium in urine
- low blood O2 - hypoxemia
what 2 things are needed for normal kidney function?
- adequate glomerular perfusion
- Functional nephrons
What is azotemia?
an accumulation of metabolic waste products in the blood (ex; Urea, Creatinine) Basically, filtration isn’t working
What is Uremia?
a group of signs and symptoms that occur due to inadequate renal function and all the waste in the blood
- it’s a huge list
how much urine output = oliguria?
<400 ml/day
how much urine output = anuria?
<40 ml/day
What is urea?
break down of proteins
what is creatinine?
breakdown of muscle
which gets absorbed a little bit, urea or creatinine?
creatinine
How fast/slow do we see AKI onset?
quickly
hours to days
which is potentially reversable? AKI or CKD?
AKI
What is the most common cause of AKI?
ATN - acute tubular necrosis
- ischemia damages cells
- nephrotoxins damage cells
3 stages
1. initiation
2. maintenance
3. recovery
What is the most common cause of death in AKI?
sepsis
waste builds up too fast and it can lead to septic shock
septic shock quickly leads to organ failure of multiple systems at once = death
What is the best indicator of AKI?
blood work - easy to see the changes
What is the general goal when someone has CKD?
slow the progression/ damage
What is the most common cause of CKD?
diabetic nephropathy - uncontrolled diabetes
What is it about diabetes that causes artery issues?
high glucose triggers an enzyme to increase calcium channel activity so then there is more constriction on the artery = narrowing = less blood and O2 = high BP = damage to the arteries in the kidney
Is diabetic nephropathy a macrovascular complication or microvascular?
microvascular - think tiny arteries
What are the 2 common causes of CKD?
- diabetic nephropathy
- HTN
What specifically causes the development and progression of CKD (inside the kidney)
Death of Nephrons - when too many die you get CKD
how many % of nephrons die before we start seeing sympyoms?
50-75%
How many nephrons can you lose before RRT is needed?
90%
What does CKD stage 1 represent?
Normal kidney function but at risk for CKD or mild kidney damage
what are the symptoms of someone in stage 1 CKD?
likely none
What does CKD stage 2 represent?
mild reduction in GFR
what are the symptoms of someone in stage 2 CKD?
may be asymptomatic
OR
trouble concentrating urine - use urine specific gravity test
maybe increase or decrease of urine
maybe anemia
What does CKD stage 3 represent?
moderate reduction in GFR
confirmed CKD if in this stage <60ml/min for >3 months
50% function lost
what are symptoms of someone in stage 3 & 4 CKD?
may be asymptomatic
OR
electrolyte & fluid imbalances
worse anemia
oliguria <400ml
azotemia
What does CKD stage 4 represent?
severe reduction in GFR
What does CKD stage 5 represent?
ESRD - end stage renal disease
What symptom do we see in stage 5 CKD?
uremia - all the bad things that make the body toxic. Kidneys no longer doing what the body needs so need RRT or transplant
What is hyperfiltration and how does it affect nephrons in CKD?
The remaining nephrons have to work too hard
What stage do patients likely start experiencing symptoms of CKD?
stage 2
What effect does hyperfiltration have in CKD?
over time it causes fibrosis and scaring
what is glomerulosclerosis ?
fibrosis and scaring of the nephron due to hyperfiltration in CKD
what are the 3 secondary functions of the kidney?
- hormone secretion - RAAS
- EPO to make RBC
- activate vitamin D to help absorb calcium
What hormone is released from the kidney when there is hypoxia?
Epo
in early CKD is sodium normally low or high?
initially low
At what point in CKD does sodium become high?
when the disease progresses
why do we have to look at both eGFR and not just blood work to determine kidney damage?
because other factors can throw off urea and creatinine levels
1. race
2. age
3. sex
in kidney disease, calcium is decreased in 2 ways. what are they?
- not enough vitamin D secreted to absorb dietary calcium
- high levels of phosphate bind to calcium
What glands recognizes decreased calcium serum levels and what do they secrete?
parathyroid glands
parathyroid hormone (PTH)
What does PTH do with calcium?
causes calcium to be released from the bones to help increase serum level
what is the problem with PTH in CKD- why is it counter productive?
Because it causes more calcium release and that hurts the bones but more importantly, it binds to phosphate and metastatic calcification.
calcification can get into the nephrons and cause issues
how does the body initially try to compensate for increased H+ due to not being able to secrete it through the kidneys as well in CKD?
kussmals respirations (respiratory response first)
Why does metabolic acidosis happen with CKD?
can’t get rid of H+ effectively
can’t balance bicarb effectively
what are the 3 hematological issues with CKD that we see in blood work?
- anemia b/c less epo
- platelet aggregation deficiency b/c uremia blocks it so people have GI bleed
- altered leukocyte function - b/c of uremia
what would we see in someone who has CKD based on their hematological blood work?
- anemia- SOB, fatigue, increased RR
- GI bleeding - hypotension, blood in stool, vomit, elevated HR, fatigue, LOC issues
- infection - b/c not as many WBC
