2 - CKD (Shepler) Flashcards
Define CKD and ESRD.
abnormalities of kidney structure, present for >3 mos w/ implications for health
Stage 5 is ESRD.
GFR <60 mL/min/1.73m^2 (cat 3a and greater)
markers of kidney damage: albminuria,
urine sediment abnormalities,
electrolyte and other abnorm d/t tubular disorders
histological/structural abnormalities
hx of renal transplant
Differentiate 5 stages of CKD w respect to kidney fxn/GFR.
G1 - >= 90 --> normal or high G2 60-89 --> mildy decr'd G3a 45-59 --> mildly to mod decr'd G3b 30-44 --> mod to sev decr'd G4 15-29 -->sev decr'd G5 <15 --> kidney failure =ESRD
Explain how diuretic resistance develops and how it can be overcome.
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Describe the relationship btw Ca2+, PO4-, vit D, and PTH in a pt w CKD.
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Decribe G2 category for GFR for CKD
G2 60-89 –> mildy decr’d
Decribe G2 category for GFR for CKD
G2 60-89 –> mildy decr’d
Decribe G3a category for GFR for CKD
G3a 45-59 –> mildly to mod decr’d
Decribe G3b category for GFR for CKD
G3b 30-44 –> mod to sev decr’d
Decribe G4 category for GFR for CKD
G4 15-29 –>sev decr’d
Decribe G5 category for GFR for CKD
G5 <15 –> kidney failure =ESRD
How should kidney fxn be estimated for stable kindey fxn?
Cockroft and Gault for CrCl
MDMR for GFR
What is the Cockroft Gault eqn?
CrCl (mL/min)=(140-age)IBW/(SCrx72) for women x0.85
Decribe the Cockroft Gault eqn.
used to esimate CrCl (GFR) for pts w stable kidney fxn
-tends to overestimate renal fxn in mod to sev kindey imp
What is the use of the MDMR eqn?
stage kidney fxn
most accurate measure of GFR
includes adj for race and gender
What occurs is kidneys are unable to excrete waste products of metabolism?
urea, ammonia, bilirubin, uric acid etc.
build up in blood, resulting in incr BUN, pruritus, confusion, N/V, anorexia) ==>uremia
What occurs if kidneys are unable to regulate fluid and electrolyte balance?
edema, fluid overload, CV complications (incr systemic vascular resistance)
What happens if kidneys are unable to maintain acid balance of plasma? (secrete H+ ions)
metabolic acidosis
What occurs if the kidneys are unable to secrete hormones?
erythropoietin, rennin, PGAs…
anemia
What happens if the kidney is unable to syntehsize calcitriol?
calcitriol-actve form of vitD
–> mineral and bone disorder (incr in PTH)
What is the definition of uremia?
a cluster of sx which is assoc’d w ESRD from any cause.
Sx are d/t accumulation of waste molecules in the blood that are normally removed by the kidneys.
Clinicians monitor the BUN to assess S/Sx of uremia.
What are the effects of uremia?
- CNS: encephalopathy, confusion
- EENT: uremic fetor
- pulm: non-cariogenic pulm edema from volume overload
- cardio: sodium retention, volume overload, LVH
- GI: anorexia, NV, constipation, metallic taste
- MS: mineral and bone disorder and Restless Leg Syndrome
- anemia
- skin-uremic frost
Describe fluid retention in CKD.
water retention is a problem, pts devo pitting edema and BP incr
What is the Tx for fluid retention in CKD?
- fluid restrict? not nec is sodium controlled. avoid large amts free water.
- diuretics for volume overload or HTN
What are considerations for using diuretics in fluid retention with CKD?
- thiazides are ineffective when CrCl <30 mL
- loops will work when CrCl <30 mL/min
- furosemide bioavailability (~100-100) is ~50%, so po dose may be 2x IV dose
- avoid K-sparing diuretics
- as renal fxn declines, and loop dose is max’d, may add thiazide to overcome diuretic resistance
How should you use different loop diuretics if a pt doens’t respond well?
loop diuretics are all similar. if poor response to one then poor response for all.
Describe (loop) diuretic resistance.
loops block NaCl, K reabs in ascending loop.
Over time cells in DCT hypertrophy and incr Na reabs to compensate–> resistance
–> can add a thiazide to block this effect if CrCl <30 mL/min
Ethacrynic acid is useful as a
loop diuretic for pts with sulfa allergies. (not a sulfonamide)
but carries a high risk for ototoxicity
How should electrolyte imbalances be treated in pts with CKD?
Na–no need to sev restrict beyond no salt die unless Tx for HTN or edema
Ka–restrict to 3 g/d
How should salt imbalances be treated in pts with CKD?
no need to retrict beyond a no salt added diet unless HTN or edema
- use saline IV solns w caution
- make oupts aware of hidden high Na foods (hot dogs, canned soups, etc.)
If a CKD pt is being treated for HTN or edema what should their sodium intake be restricted to?
<2 g Na/d
<5 g NaCl/d
What is the potassium intake restriction for CKD pts?
restrict to 3 g/d
goal for ESRD pts is pre-dialysis K of 4.5-5.5 mEq/L)
What are high-potassium foods?
tomatoes
dried fruits
salt substitutes
fresh fruits
How should hyperkalemia be treated in CKD pts?
- dialysis
- calcium gluconate IV (cardio-protective)
- nebulized albuterol
- insulin + glucose
- sodium polystyrene sulfnate (Kayexalate) (15-30 g btw dialysis sessions)
- NaHCO3 (not used for ESRD pts)
What are the key points to remember for mineral and bone disorder (CKD-MBD)?
- hyperphosphatemia (can’t elim)
- decr vit D
- hypocalcemia
–>increase in iPTH
What are the consequences of increased iPTH?
increased calcium mobilization from bone
–> weakened bone fracture more easily
How does hyperhposphatemia cause hypocalcemia?
phosphate binds calcium and preciptates
–>soft tissue calcifications
Describe hyperphosphatemia for ESRD pts.
affects nearly all
–>nearly all receive phosphate binders
How are phosphate binders given?
WITH FOOD
bind dietary phosphate in GI–elin in kidneys
What are the two main types of phosphate binders?
calcium and non-calcium
don’t use calcium if hypercalcemia!
What are the calcium-containing phosphate binders?
calcium carbonate (Tums) calcium acetate (PhosLo)
How much elemental calcium is in Tums? What is the dose as a phosphate binder?
40% elemental calcium
500 mg (as elemental Ca) tid c meals
How much elemental calcium is in PhosLo? What is the dose as a phosphate binder?
25% elemental calcium
2-3 tab tid c meals
Compare phosphate binding between calcium carbonate and calcium acetate?
acteates binds 2x as much PO4- compared to carbonate.
acetate may produce fewer hypercalcemic events
What are the non-calcium containing phosphate binders?
Sevelamer carbonate (Renvela) lanthanum carbonate (Fosrenol) sucroferric oxyhydroxide (Velphoro) Auryxia (ferric citrate) AlOH (Amphojel) Magnesium carbonate (Mag-Carb) nicotinic acid and nicotinamide
What are the dose and adverse effects of sevelamer carbonate (Renvela)?
Phos 5.5-7.5 mg/dL –> 800 mg tid
Phos >=7.5 mg/dL –> 1600 mg tid
Adverse (rare): GI upset, N/V/D, decreased LDL by 15-30%
not abs’d –> low risk of systemic toxicitiy
decr uric acid serum conc
What is the dose of Lathanum carbonate (Fosrenol)?
250-750 mg tid c meals
titrate to 1500-3000 mg/d
What is the brand number of sevelamer carbonate?
renvela
What is the brand name of lanthanum carbonate?
Fosrenol
What is the claim to fame for lanthanum carbonate (Fosrenol)?
binds phos at lower pH
not sure if clinically relevant
Describe the distribution and SE of lanthanum carbonate.
eliminated in feces
no long-term accumulation
dose not cross BBB
SE: mostly GI: N/V/D
Which two phosphate binders contain iron?
sucroferric oxyhydoxide (Velphoro) Auryxia (ferric citrate)
Descibe the dose and affects of sucroferric oxyhydroxide (Velphoro).
500 mg chewable tab tid c meals
titrate by 1 tab/d q week
may cause darkened stools d/t iron
ironot abs’d, does not affect TSAT or ferritin
What is the dose and affects of Auryxia (ferric citrate)? What pt pop is this phosphate binder used in.
2 tab tid c meals
q tab has 1 g ferric citrate –> incr TSAT and ferritin
may cause discolored feces
used in CKD pts on dialysis
Describe the dose and use of aluminum hydroxide (Amphojel) as a phosphate binder?
300-600 mg tid c meals
old therapy, not used much anymore
causes alumnium toxicity
What is the dosing of magnesium carbonate (Mag-Carb) as a phosphate binder?
1-3 tab tid c meals
How is dietary phosphate restricted in CKD pts?
restict to 800-1000 mg/d if
CKD 3&4: Phos >4.6 mg/dL
CKD 5: Phos >5.5 mg/dL
PTH > target range for stage 3, 4, or 5
What are foods that contain high phosphorus
meat nuts dairy dried beans colas beer
Describe the relationship between Vitamin D and SHPT in CKD?
yperhpos and the kidneys inability to activate vit D –> decr serum calcium –> incr PTH secretion –> incr Ca mobilization
What are the two main types of Tx used to treat SHPT dd/t vit D deficiency?
Vitamin D therapy
active vitamin D sterols
these incr vit D conc and decr PTH through neg feedback
Describe vit D synthesis pathway.
cholcalciferol (from 7-dehydrocholesterol in skin after sun) and egocalciferol (from food)
- -> 25-hydroxvitamin D in liver
- -> 1, 25-dihydroxyvitamin d or calcitriol) in kidney
–> binds to vit D R to cause biological actions
Which CKD patient population requires active forms of vit D?
not enough kidney fxn to convert 25-hydroxyvitamin D to calcitriol
Stage 5 ESRD
What are the inactive vitamin D products?
ergocalciferol (Calciferol) - vit D2
Cholecalciferol - vit D3
What is the dose and use of ergocalciferol (Calciferol)?
1x 50,000 IU cap per month
For vit D insuff in CKD stage 3 and 4
What is the dose and use of cholecalciferol?
1000 IU po d
for vit D insuff in CKD 3 & 4
What is the dose of calcitrol (Rocaltrol and Calcijex)
Roacltrol 0.25 mcg po d or qod; may incr q4-8 wk up to 0.5-1 mcg /d
Calcijex 0.5 mcg/d IV 3x q wk
What are the adv/disadv of calcitriol?
approved for pediatric use
cheapest
greatest risk for hypercacemia (soft tissue calc)
What are monitoring parameters for calcitriol?
S/Sx hypercalcemia (fatigue, weakness, HA, N/V, muscle pain, constipation)
What is the dose of paricalcitol (Zemplar)?
IV: 0.04-0.10 mcg/kg 2-3x/wk
PO: PTH <=500 pg/mL –> 1 mcg d or 2 mcg qod
PTH >500 pg/mL; 2 mcg d or 4 mcg qod
What are the active vit D products used to treat SHPT in CKD?
Calcitriol (Rocaltrol and Calcijex)
Paricalcitol (Zemplar)
Doxercalciferol (Hectorol)
What are the monitoring parameters for paricalcitol (Zemplar)?
ca
Phos
iPTH
vit D (lab is for inactive form)
You have a patient with CKD who is receiving an inactivated vitamin D supplement. Both their vit D (inactive) and iPTH levels are high. What do you do?
change to activated vit D form bc kidney does not seem to be activating vitD
What are the adv/disadv to paricalcitol (Zemplar)?
> =30% reduction in iPTH
approved for peds
most favorable ADE profile
less calcemic activity compared to calcitriol
What is the does of Doxercalciferol (Hectorol)?
2.5-10 mcg po or IV 2-3x/wk
What are the three parts of CKD-BMD?
hyperphosphatemia
vit D and SHPT
calcium and SHPT
What are the adv/disadv of doxercalciferol (Hectorol)?
hepatically-activated prohormone
- -> can’t be used in severe alcholics, heaptic failure
- produces more even serum conc that more closely mimic normal
- > +30% reduction in iPTH
- higher incidence of hyperphosphatemia compared to paricalcitrol
- lower incidence of hypercalcmia compared to calcitriol
What drug is in the calcimimetic class?
Cinacalet (Sensipar)–type II calcimemtic
What is the moa of cinacalecet (Sensipar)?
mimics action of ca but does so by binding to CaR and inducing conformation change to the R, triggering the parathyroid gland to decr PTH secr
What is the dose of cinacalcet (Sensipar)?
30 mg po d
incr dose to achieved desired PTH serum conc
max daily dose 180 mg
** When in cinacalcet (Sensipar) contraindicated?
hypocalcemia!
if Ca <7.5 mg/dL, withohold cinacalcet until Ca >=9 mg/dL
What is the corrected calcium eqn?
Ca corr= Ca measured + 0.8 x (4-serum alb)
What are the monitoring parameters for CKD-MBD
Ca
Phos
25(OH)D
iPTH
What is the goal Ca for CKD-MBD?
8.5-10.5 mg/dL
What sit he goal phos for CKD-MBD?
2.5-4.5 mg/dL
What is the goal 25(OH)D for CKD-MBD?
~30 ng/mL
What is the goal iPTH for CKD-MBD?
ND: 11-54 pg/mL
D: 100-500 pg/mL
What are the mechanisms by whih ESRD patients develop anemia?
- decr erythropoietin prod
- uremia decreases RBC lifespan
- vit losses during dialysis-folate, B12, B6
- dialysis–loss of blood through dialyzer (hemolysis)
What are macrocytic anemia?
folate, B12 def
What are normocytic anemias?
anemic of chronic disease
GI bleed
erythropoietin def
What are causes of microcytic anemia?
iron def
aluminum tox
What are S/Sx of anemia?
fatigue!!! dizziness HA pallor decr cognition
***What is the normal MCV range?
80-96 microm^3
**What is the normal RDW range?
11.5-14.5 %
What are tx goals for anemia in CKD pts?
- reverse S/Sx of tissue hypoxia and LVH
- incr exercise tolerance and capacity
- optimize survivial
- incr QOL
What are monitoring parameters for anemia in CKD pts?
Hb–>best
Hct is less stable w storage, non-standardized assay, and increases w hyperglycemia
Hg doesn’t have these probs
How often should Hb be montiored in CKD pts?
CKD3: annually
CDK4-5ND: 2x/yr
CDK-5K: q 3 mos
if existing anemia then for CKD3-5ND q3mo, CKD5D q mo
When should anemia be diagnosed in CKD pts? (Hg cutoff)
<12 g/dL in females
<13 g/dL in males
What are Txs for anemia in CKD pts?
iron
ESAs
According to KDIGO, when should iron be supplemented?
TSAT <30%
serum ferritin <500 ng/mL
if above these then enough for erythropoiesis
What is functional iron def?
low TSAT
How often should TSAT and ferritin be monitored?
at least q 3 mo
Describe the use of po iron in CKD pts?
will not likely be sufficient for HD pts
–> CKD pts (3&4) or periotoneal dialysis pts
What is the dose of oral iron?
200 mg of elemental iron qd
usually 64 mg elemental in 325 mg ferrous sulfate
What are the adv of heme iron over ferrous salts
greater abs
different abs site
not subject to 200 mg elemental iron rule
What are heme iron products and their doses?
Proferrin ES and Proferrin Forte
2-3 tab/d (24-36 mg/d
12 mg elemental iron/tab)
What are the SEs of oral iron? How are these dealt w?
Se: stomach upset
Fe abs’d in acidic environment
- -food decr abs
- take w orange juice (watch vit C! b/c renal elim)
separate from Ca by 2 hr d/t binding
may not be appropriate for pts on meds that incr pH (antacids, PPIs, H2 blockers)
What are IV iron agents used in CKD?
iron dextran (InFed, Dexferrum) sodium ferric gluconate (Ferrlicit) iron sucrose (Venofer) ferric carboxymaltose (Injectafer) ferumoxytol (Feraheme)
Describe the effects of low MW vs high MW in IV iron agents.
high MW such as Dexferrum cause the most complications.
Which IV iron products require a test dose?
iron dextran (InFed, Dexferrum)
What are possible SE of iron IV products?
flushing
dizziness
hypotension
iron dextran—> anaphylactic rxns
What IV iron product interferes w MRI? How long does this effect last?
ferumoxytol (Feraheme)
for up to 3 mos after 2nd inj!
What is the dosing of iron dextran (InFed, Dexferrum)?
25 mg test dose**
100 mg IV q HD session x 10 doses
25-100 mg /wk maintenance
What is the dosing of sodium ferric gluconate (Ferrlicit)?
125 mg IV q HD session x 8-10 doses
31.25-125 mg/wk maintenance
What is the doing of iron sucrose (Venofer)
100 mg IV q HD session x 10 doses
OR
200 mg IVP x 5 doses (for ND-CKD pts)**
25-100 mg/wk maintenance dose
What is the dosing for ferric carboxymaltose (Injectafer)
750 mg IV once, repeat in 7 days
What is the dosing for ferumoxytol (Feraheme)
510 mg IV once, repeat in 3-8 d
What are the monitoring parameters for IV iron agents?
HR, BP, RR< q 15 min
Ferritin, TSAT q1-3 mo
for all agents except Feraheme.
Feraheme: ferritin, TSAT q1-3 mo
What iron agent can be added to dialysate?
triferic (ferric pyrophosphate citrate)
What is it suggested to begin ESA?
after all other correctable cause sof anemia have been address
CKD 3-5ND HB <10g/dL; Hb falling at a rapid rate; needed to avoid blood transfusion
CKD 5D Start when Hb 9-10 g/dL
Do not use ESA to push Hb above ___ d/t incidence of ___
11.5 g/dL
cerebrovascular events
What are the FDA recommendations for ESAs?
CKD3-5ND: Hb<10 g/dL and falling rapidly; reduce or interrupt dose i Hb>10g/dL
CKD5D: initiate if Hb<10 g/dL; reduce of interrupt dose if Hb approaches or exceeds 11 g/dL
What are the two ESAs?
recombinant human erythropoietin (rHuEPO, epoetin alfa, Epogen, Procirit, EPO) darbepoietin alfa (Aranesp)
What is the dose of recombinant human erythropoietin?
120-180 U/kg/wk IV divided into 3 doses
80-120 U/kg/wk SC divided into 2-3 doses
SC-preferred
IV-increased cost
If target Hb/Hct reached, SC dose is 2/3 IV dose. Below target then use same dose.
What is the dosing for darbepoetin alfa?
3x longer t1/2 then epoietin alfa
dosed once /wk IV or SC
starting dose 0.45 mcg/kg–titrate to maintain Hb of 12g/dL
What are adverse effects of ESA use?
PRCA: pure red cell aplasia: antibodies devo to erythropoietin –> d/c drug permanently
HTN:
23% of CKD pts have HTN
w incr Hb w ESA –> incr cardiac arrest, stroke, CHF, HTN, acute MIs
What are clinical considerations for dose titration of ESAs based on Hb?
-monitor Hb wkly during initiation
-adjust no more oft then q 4 wks
goal=1-2 g/dL rise/month
-incr dose by 25% if Hb does not incr by 1 g/dL in 4 wks
-decrease dose by 25% when Hb approaches 11-11.5 g/dL or incr by more than 2 g/dL in 4 wks
What are causes of ESA therapy failure?
lack of vitamins or iron aluminum toxicity active bleed drug-induced bone marrow suppression acute inflamm or infx
Describe acid-base disorders in ESRD pts.
cannot excrete H+ ions –> metabolic acidosis
What is the tx for metabolic acidosis in ESRd pts
- dialysis –incr bicab in dialysate
- Shohl’s soln–1 mEq sodium + 1 mEq bicarb (as sodium citrate) per mL of soln
- NaHCO3 tab 325 and 650 mg strength (1 g NaBicab=11.9 mEq Na and 11.9 mEq bicarb)
- Dose (mEq) = [0.5 L/kg (IBW)] x (12-actualHCO3-)
What are the protein requirements if GFR <30 mL/min?
0.8 g/kg/d
What are the protein requirements for ESRD on HD?
1.2 g/kg/d
What vitamins are replaced in renal nutrition?
B and C –> pulled off in water by dialysis
Nephrocaps, Nephron FA
What are the energy requirements for CKD?
<60 yoa 35 kcal/kg/d
>60 yoa 30-35 kcal/kg/d
