Kidney Flashcards
What are the 3 functions of the kidney?
Excretory
Endocrine - RBC , renin
Metabolic - vitamin D, gluconeogenesis
What is the path of the kidney?
Afferent (efferent out) - glomerulus -proximal - descending- ascending (water )- distal - collecting duct
What does renin do?
Vasoconstrict and Na and water retention
What gets vasoconstricted from Angio 2?
Efferent arteriole
Where is aldosterone secreted from?
Adrenal cortex
What is aldosterone’s role?
Resort Na for K and retain water
What is ADH job?
Retain water
What is ANR’s job?
Get rid of water
If GFR is low what is S Cr?
Higher
What equation uses GFR and classifies the severity of kidney disease?
CKD - EPI
What equation uses s Cr?
Cockcroft - gault
What condition must the patient if are using ckd-epi?
CKD duh but must be stable
What are the limits of using equations estimate function?
Extremes of mass, muscle
What does non-indexed or No normalization mean?
Adjusted to patients BSA
How does bun change in kidney disease?
Increases
What can also change bun?
Eating protein
Gi bleed
Hydration (low h 20 =↑ urea)
What are the ACR ranges of albumin?
A 1= <3
A2 = 3-30
A3 = > 30
What range is microalbuminaria?
3 - 30
What can cause transient albuminuria?
Major exercise , UTI, period,
What does a urinalysis look at?
Color, turbidity, casts, glucose, pH,
What are the most common casts, and what causes it?
Hyaline - exercise, looks concentrated
Granular - CKD, brown
What is definition of AKI?
Sudden decline in renal function
True or false: you can use CKD - EPI if they have AKI?
False need stable
What is lab values for AKI?
S Cr > 0.3 in 48 hours or > 1.5 times baseline
Urine < 0.5 ml/kg/hr for 6 hrs
What is anuric?
< 50ml/day
What is oliguric?
< 500mi/day
What is non-oligaric?
> 500mi/day
What can change urine output?
Dehydration and diuretics
What marker usually shows up first for AKI?
↓ urine output ,s Cr takes 4 days
Sx of AKI?
Vomit, ab pain, dark urine. Foamy urine, edema, malaise
What can be general causes of AKI?
Mostly Anything that changes blood flow to the kidney- sepsis, trauma, burns, drugs(
What can be causes of prerenal azotemia?
blood loss, dehydration, HF, hypotension, low glomerular pressure (ACE/ARB, NSAIDS)
WHat are the 4 main types of Intrinsic AKI?
Tubular, intersitial, glomerulonephritis and vascular kidney injury
What causes tubular necrosis?
toxins mostly aminoglycosides (micins) and myoglobin
WHich type of kidney injury would statins cause?
rhabdomyolysis= tubular necrosis= intrinsic AKI
What can cause interstitial nephritis?
idiopathic immune response= NSAIDS and penicillin
WHat is a form of vascular kidney injury?
renal artery stenosis
WHat are some causes of post renal AKI?
obstruction= kidney stones, prostate, cancer, drugs (sulfonamides, MTX, Acyclovir)
What are the general 4 things used to diagnose AKI?
history
Lab data- increased S Cr, BUN, acidosis, hyperkalemia
FEna= % of sodium filtered and excreted
Urinalysis- casts
What does a high FEna mean?
tubular damage
What does a low FEna mean?
pre renal AKI
WHat other things can change FEna value?
RAAS and diuretics
If a patient had acute tubular necrosis, what form of cast could they have?
cellular
If a patient had increased WBC what can this indicate?
UTI
If crystals were present, what form of AKI would the patient have?
post renal
How can we treat pre renal AKI?
hydration/ stop diuretics
BP support
perhaps fluid removal
stop/hold nephrotoxic meds
How can we treat intrinsic AKI?
stop offender, manage autoimmune
How can we treat post renal failure?
catheter, remove obstruction, hydration
What is the range of good potassium?
3.5-5.0
What are signs of moderately high potassium?
weak, confused, peaked T waves
What are signs of severely high potassium?
wide QRS and small p Waves- heart block
If a patient came in with mildly high K, what are we doing?
15-60 mg BID-QID of sodium polystyrene or furosemide
WHy might furosemide not work to remove K+?
need functional kidneys
Why cant sodium polystyrene be used for severe k+?
too slow- one hour
If severely high K+ (>7), what are we doing?
calcium gluconate to protect heart
use insulin to drive K into cells
sodium bicarb if metabolic acidosis
then sodium polystyrene
What if all else fails to lower K?
dialysis
What are our go to agents if fluid overload?
furosemid +/- metalazone
Patient arrives to the ER with metabolic acidosis, what will be done to help?
sodium bicarb IV
When should dialysis be used to treat AKi (Hint: AEIOU)
A-acidosis
E-electrolytes- high K
I- Toxic ingestions
O- Fluid overload
U- Uremia
TOP 2 for AKI
and BOTTOM for CKD
What is the leading cause of CKD?
diabetes and HTN
What are the early stage symptoms of CKD?
ASYMPTOMATIC
What population in Canada is at risk for CKD and maybe could benefit from increased screening?
First Nations- higher rates of diabetes
What is the clinical definition of CKD?
under 60 ml/min GFR WITH or WITHOUT Kidney damage/ACR>3 mg/mmol for at least 3 months
How often should you be screened for CKD if the patient is high risk?
annually
When should the patient be refered to a nephrologist?
<30 ml/min and > 60 ACR
Why is CKD more prevalent in older people?
higher rates of diabetes and HTN
At age 30 what happens to your GFR?
lowers by 1 ml/min ish a year
Since we know that with age your kidney function declines, if the patient is >80 and has a GFR under 60 will this always be CKD?
No- if no marker of kidney damage
Stages of CKD using GFR
G1- >90
G2- 60-90
G3a- 45-60
G3b- 30-45
G4- 15-30
G5- <15/ dialysis
Stages of CKD for albuminuria
A1-<3
A2-3-30
A3- >30
If we want to determine GFR which equation will we use?
CKD-EPI
What is usually the first sign of CKD if the patient is diabetic and poor sugar control?
albuminuria
At what stage of CKD does the patient become symptomatic?
> stage 3
What are the symptoms of CKD?
fatigue, cloudy urine, edema, SOB, pruritis
What is associated with faster progression of CKD?
low GFR and high albuminurea, diabetes, male, african, age
Overview of interventions of delaying progression of CKD?
Blood pressure control
RAAs block
SGLT2- diabetic
smoking cessation
avoid nephrotoxins
Explain how HTN can cause and be a complication of CKD.
can cause it by damaging the glomerulus
and low GFR can stimulate RAAS to retain more fluids
What is blood pressure target for diabetics?
<130/80
What is blood pressure target for high risk?
<120/80
What is blood pressure target for most people?
<140/80
Who wasn’t included in the sprint trial?
diabetics= found that <130 is better in a different study
Who is considered high risk for blood pressure control? Hint AARF
A-age >75
A-athersclerosis
R-renal (CKD)
F-framingham risk score>15%
What would a BP target <120 do for diabetics?
NOT improve progression/ESRD
may even worsen it
What is salt restriction for people?
<2 grams. but as much as you can
Good technique for BP testing?
sit upright, feet flat, arm su[ported, dont talk or move
What is limit for alchol for BP?
1-2 drinks a day
What is first line for BP control?
ACE/ARB, diuretic, long acting CCB
What is first line for HTN if albuminurea too?
ACE/ARB- is the absolute best!
MOA of ACE/ARB
dilate efferent arteriole
When should ACE/ARB not be used?
angioedema, renal artery stenosis= >30% decrease of GFR when starting, pregnant, hypotension and high K+
What monitoring for ACE/ARB?
BP, SCr, K, ACR
If patient is at target BP but not yet max dose of ARB what is the next step?
keep increasing dose and maybe back off other BP meds
A patient has been on perindopril for 10 years and has just now got a GFR under 30 ml/min. What should be done?
DO NOT SWITCH/ STOP- just monitor more
Is it okay to combo ACE/ARB?
NO- hurts kidneys (K+),
What is an example of a direct renin inhibitor?
aliskiren
Compare with ACE, how does Aliskiren stack up?
more s/e such as stroke, renal issues, hyper K, hypotension
What benefits are given when adding a MRA?
lower proteinuria, slow progression,
Cons of MRA?
MORE hyper K and gynecomastia
What are the steroidal MRAs?
spirinolactone, eplerenone (less s/e)
What are the non steroidal (selective) MRAs?
finerenone- much less side effects better for diabetics
Since finerenone is so good. Can we use this for HF instead of steroidal ones?
NOOO, dont use