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Flashcards in 5 Nephrology and Acid-Base Deck (36):
1

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

2

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

3

Dialysis indications

AEIOU:

acidosis
electrolyte
ingestion
overload (CHF, edema)
uremia

4

ATN: think what 3 main causes

prolonged ischemia, drugs/toxins, and contrast

5

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.

6

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

7

Intrarenal ARF:

BUN/Cr
UNa
FENa

kidney is broken; can't reabsorb Na or concentrate urine.

BUN/Cr<10
UNa>20
FENa>1%

8

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

9

Pt gets ARF, with increased Cr.

What labs to get first?

First, r/o prerenal:

BUN/Cr
UNa
FENa
FE Urea if diuretics

10

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

11

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

12

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

13

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

14

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)

15

side effect of EPO in ESRD

worsening HTN

16

contrast induced ATN. when after use does it occur?

ARF 7-10 days post procedure

17

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

18

How to corrent Na and Ca

Na: every 100 over 100, add 1.6

Ca: every 1 albumin <4, decrease Ca by 0.8

19

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

20

hungry bone syndrome

after parathyroid adenoma removal, the remaining glands take time to rev back up. So temporary hypoCa

21

HyperCa of malignancy. mechs?

Also, sarcoid mech

1. mets to bone
2. PTH-rp (Squamous cell carcinoma)

3. increase in 1,25 VitD

22

Young pt hospitalized after MVC trauma. Now has hyperCa, think what

HyperCa of immobilization. Get them walking and out of bed

23

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

24

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.

25

hyperCa of malignancy form bone breakdown, Tx

Vigorous hydration, alendronate. Lasix probably not, lost favor.

26

HyperK sxs (3) other than EKG change

-areflexia
-flaccid paralysis
-paresthesias

27

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

28

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

29

kidney stones: what is medical expulsion therapy

when to use

CCB and alpha blockers
amlodipine, terazosin.

Can use if <7mm

30

Struvite stone classic story

Elderly pt with frequent UTIs. UA shows hematuria, no pyuria, and ALKALINE urine

31

kidney Stone sizes to know


<5mm IVF and analgesia
<7mm can use MET
>30mm surgery for sure

In between: depends, lithotripsy, uretoscopy, etc

32

PCKD
-think what 3 extrarenal things

cysts in:
-brain
-liver
-pancreas

So, SAH, cirrhosis, pancreatitis

33

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

34

Predicted anion gap

Albumin x3. So, with alb 4, AG predicted is 12

Alb 2, predicted is 6.

35

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

36

metabolic acidosis, non-AG.
-how to approach dx

Get urine anion gap.
(Urine Na + K - Cl). NOT SAME ELECTROLYTES as blood AG

If +, then RTA
If -, then diarrhea