Flashcards in 5 Nephrology and Acid-Base Deck (36):
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Casts:
-Fatty casts
-granular/muddy brown casts
-RBC casts
-WBC casts
-waxy casts
-hyaline casts
-Fatty--nephrotic
-granular/muddy brown casts--ATN
-RBC casts--GN
-WBC casts--AIN, pyelo
-waxy casts--CKD
-hyaline casts--Normal
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CKD stages
-GFR
-tx goals
1. >90.
2. 60-90
3. 30-60 complications start appearing, tx them
4. 15-30 prepare dialysis (get AV fistula now so it can heal)/transplant
5. <15. ESRD, dialysis required
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Dialysis indications
AEIOU:
acidosis
electrolyte
ingestion
overload (CHF, edema)
uremia
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ATN: think what 3 main causes
prolonged ischemia, drugs/toxins, and contrast
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ATN:
-3 phases
-how long take to recover, what tx
1. prodrome: increased Cr
2. oliguric: UOP deceased (fluid overload!)
3. polyuric: UOP increased (diuresis!)
2-3 weeks for tubular cells to regenerate. Do supportive dialysis to prevent life-threatening e-lyte imbalances.
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Prerenal ARF:
BUN/Cr
UNa
FENa
FE Urea
kidneys think they're dehydrated, will hold on to salt.
BUN/Cr >20
UNa<10, FENa <1% (tubular fxn intact)
Urine osmols >500 (can still concentrate)
FE Urea<35%. Use FE Urea if on diuretic
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Intrarenal ARF:
BUN/Cr
UNa
FENa
kidney is broken; can't reabsorb Na or concentrate urine.
BUN/Cr<10
UNa>20
FENa>1%
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Pt with renal damage, but needs contrast for imaging. Do what? (3 things)
prevent contrast-induced ATN.
1. vigorous hydration
2. NAC
3. stop diuretics and ACE/ARBs
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Pt gets ARF, with increased Cr.
What labs to get first?
First, r/o prerenal:
BUN/Cr
UNa
FENa
FE Urea if diuretics
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Renal Failure, my mnemonic
MR CA PUNK
Met acid, renal osteodystrophy
HypoCa (from low VitD and 2ndary hyperPTH), Anemia (low EPO)
Hyperphosphatemia, Uremia, increased Na, hyperkalemia
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CKD:
-HTN and DM treatment goals.
-what to be aware of in DM
HTN: strict <130/80
DM: A1C<7, same.
In DM, must use oral meds. NOT metformin, NOT insulin. Metformin causes lactic acidosis. Insulin cleared by kidneys, so beware of hypoglycemia with insulin retention
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Postrenal ARF:
what are the 2 stages
early stage: BUN 'forced' back into blood by pressure. BUN/Cr>15.
Tubular fxn intact, so FENa<1%, urine osmol>500
(same numbers as Prerenal)
late stage: Tubular damage, so:
BUN/Cr <15.
FENa>2%
urine osmol <500
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Intrarenal ARF: think what main 3 causes? look for what on microscopy? and main causes for each?
1. ATN (muddy casts).
prolonged ischemia, toxins/drugs, contrast
2. AIN (WBC casts from inflamm).
drug hypersensitivity (eg NSAIDs), pyelo, infiltrative dz (amyloid, sarcoid)
3. GN (RBC casts)
-many causes
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Pt with acute leukemia. You treat with chemo. What to be aware of with kidneys and what to do?
beware tumor lysis syndrome leading to ATN from high uric acid.
Give hydration and allopurinol (decrease formation of uric acid)
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side effect of EPO in ESRD
worsening HTN
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contrast induced ATN. when after use does it occur?
ARF 7-10 days post procedure
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hyponatremia:
general approach and decision points
1. Serum osmols. If low <280, then true hypotonic hypoNa. Otherwise, pseudo.
2. Volume status
-overload: CHF, nephrosis, cirrhosis
-normal volume: "RATS"
RTA, Addison's, Thyroid, SIADH
-hypovolemia. give IVF
prerenal vs intrarenal
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How to corrent Na and Ca
Na: every 100 over 100, add 1.6
Ca: every 1 albumin <4, decrease Ca by 0.8
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HyperCa sxs. what are they really
"bones, stones, groans, psychiatric overtones"
-fx, osteopenia
-Ca stones
-N/V, abd pain
-AMS, only at 13-15 severe
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hungry bone syndrome
after parathyroid adenoma removal, the remaining glands take time to rev back up. So temporary hypoCa
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HyperCa of malignancy. mechs?
Also, sarcoid mech
1. mets to bone
2. PTH-rp (Squamous cell carcinoma)
3. increase in 1,25 VitD
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Young pt hospitalized after MVC trauma. Now has hyperCa, think what
HyperCa of immobilization. Get them walking and out of bed
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Young pt with asx hyperCa and positive family hx. Think what?
FHH: Familial hypocalciuric hypercalcemia
-Bad Ca sensor at parathyroid, so secrete more PTH anyway. No tx
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hyperparathyroidism: mechs
-primary
-2ndary
-tertiary
1. adenoma
2. CKD, starting with low VitD leading to low Ca, stimulating PTH. So, Ca usu low/normal.
3. CKD/ESRD, autonomous adenomas.
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hyperCa of malignancy form bone breakdown, Tx
Vigorous hydration, alendronate. Lasix probably not, lost favor.
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HyperK sxs (3) other than EKG change
-areflexia
-flaccid paralysis
-paresthesias
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Hypokalemia:
-in real life, what 2 main groups of causes to think of
-on test, what causes to think of: (3)
1. GI losses (diarrhea, vomiting)
2. Renal losses (diuretics)
1. Bartter syndrome (Lasix)
2. RTA
3. Hyperaldosteronism
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HypoK
-how to replace K+, what rates?
-how fast do you want K to increase
-if K is not increasing, think what?
PO is best.
1. PIV: <10 meq/h because K+ burns in peripheral
2. Central: <20 meq/h because fear of arrythmia
Gen rule: 10 mEq increases K by 0.1. increasing K by 0.1/hour is ideal.
-Check Mg. replace that
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kidney stones: what is medical expulsion therapy
when to use
CCB and alpha blockers
amlodipine, terazosin.
Can use if <7mm
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Struvite stone classic story
Elderly pt with frequent UTIs. UA shows hematuria, no pyuria, and ALKALINE urine
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kidney Stone sizes to know
<5mm IVF and analgesia
<7mm can use MET
>30mm surgery for sure
In between: depends, lithotripsy, uretoscopy, etc
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PCKD
-think what 3 extrarenal things
cysts in:
-brain
-liver
-pancreas
So, SAH, cirrhosis, pancreatitis
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Renal cyst, big picture approach?
Ask yourself, is this RCC??
1. if cyst small, think simple, no tx
2. if cyst big with septations, think complex cyst, do needle bx
3. If classic triad, or paraneoplastic sxs (anemia or polycythemia), think RCC. Do CT. Then Cut it out, no bx
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Predicted anion gap
Albumin x3. So, with alb 4, AG predicted is 12
Alb 2, predicted is 6.
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metabolic alkalosis
-how to approach dx
1. volume responsive?
Measure Urine Cl. If low (<10), then contraction alk (high aldo retaining NaCl, so Cl low). Give fluids
If Urine Cl >10, not volume responsive.
-urine Cl>10 and HTN, then hyperaldosteronism (not responsive to fluids). eg RAS and Conn's syndrome
-urine Cl>10 and no HTN, then think genetic. Bartter and Gitelman
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