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Flashcards in Renal Deck (65)
1

Renal Clearance (Cx)

= Ux*V/ Px
Volume of plasma cleared per unit time (ml/min)
Px, Ux= mg/ml
V= urine flow rate
Cx reabsorption , etc
Cl inulin = GFR
Cl pah = RPF

2

GFR

clearance of inulin
about 100 ml/min
= Kf (Pgc - Pbs)- (oncgc- oncbs) but oncbs = 0 mostly
Ccr = GFR but overestimates by about 10-15% bc of secretion in the PCT

3

Osmolality

285-295 mOsm/kg water

4

Water division between body and compartments

60-40-20
60% of body
40% ICF
20% ECF (75% interstitial, 25% plasma)

5

eRPF (effective renal plasma flow)

Clearance of PAH (para-aminohippuric acid)
100% cleared (secreted by carrier and saturable transport in the PCT)
underestimates RPF by about 10%

6

RBF

= RPF /(1-Hct)

7

FF

GFR/RPF
20%

8

Filtered load

GFR * Plasma concentration

9

What is the effect of prostaglandins on afferent arteriole?

dilate (increase GFR, increase RPF, FF constant)
NSAIDS block this path

10

At what plasma glucose does glucosuria begin?

200 mg/dL
Can be decreased in normal pregnancy (decrease ability of PCT to reabsorb glucose)

11

At what plasma glucose are transporters saturated ?

375 mg/dL

12

Henderson Hasselbach

pH = 6.1 + log (HCO3-)/ 0.03 PCO2

13

Winter's formula

compensation metabolic acidosis
Pco2= 1.5 (HCO3) + 8 +- 2

14

Anion gap formula

8-12
(Na)- (HCO3- + Cl-)
Correct for albumin

15

Excreted load

= Px * GFR - [] reabsorbed

16

Most common site of ureter obstruction in fetus?

Uteropelvic junction (last to canalize)

17

What is horseshoe kidney associated with?

- uteropelvic junction obstruction, hydronephrosis, renal stones, chromosomal aneuploidy syndromes (turner, wiliams, patau, etc); infection, and rarely renal cancer

18

Excretion Rate

Ux*V

19

Reabsorption

Filtered - excreted

20

Secretion

excreted - filtered

21

RBC casts

Glomerulonephritis, malignant hypertension

22

WBC casts

Tubulointerstitial inflammation, acute pyelonephritis, transplant rejection

23

Fatty casts/oval fat bodies

nephrotic syndrome

24

Granular casts (muddy brown)

acute tubular necrosis

25

Waxy casts

ESRD/chronic renal failure

26

Hyaline casts

nonspecific, can be normal esp in concentrated urine samples

27

Mechanism of action mannitol?

osmotic diuretic
Increases tubular fluid osmolaltiy --> increases fluid flow
Also decreases intracranial pressure

28

Clinical use of mannitol?

Increased ICP, drug overdose (increases renal flow)

29

Toxicity of mannitol?

Pulmonary edema
Dehydration

30

When is mannitol contraindicated?

HF (pulmonary edema)
Anuria

31

What is the mechanism of acetazolamide?

Carbonic anhydrase inhibitor
Acts in PCT
Decreases HCO3/Na reabsorption
Decreases total body HCO3 stores

32

What are the clinical uses of acetazolamide?

Glaucoma (CA in cilliary body in eye)
Urinary alkalinzation (excrete weak acids; cystein and uric acid stones)
Pseudotumor cerebri (CA in choroid plexus)
Altitude sickness

33

What is the toxicity of acetazolamide?

Hyperchloremic metabolic acidosis
Parathesias
NH3 toxcity (encephalopathy with hepatic impairment)
Sulfa allergy
CaPh stones

34

What is the mechanism of furosemide action?

Blocks the NKCC pump in the TAL
Sulfonamide diuretic
Stimulates PGE release to vasodilate afferent arteriole

35

What is furosemide used for?

Edematous states
HT
Hypercalcemia

36

What is the toxicity of furosemide?

OH DANG!
Ototoxicity
Hypokalemia

Dehydration
Allergy to sulfa
Nephritis (interstitial)
Gout

37

When would you use ethacrynic acid?

Diuresis in sulfa allergic patients
Same action as furosemide
Phenoxyacetic acid derivative

38

What is the mechanism of HCTZ?

Blocks the NCC pump in the early DCT

39

Clinical use of HCTZ

HT, HF, idiopathic hypercalciuria, nephrogenic DI, osteoporosis

40

Toxicity of HCTZ

Hypokalemic metabolic alkalosis
Hyponatremia
hyperGlycemia
hyperLipidemia
hyperUricemia
hyperCalemia
(hyperGLUC)
sulfa allergy

41

Mechanisms of action of Spirnolactone?

competitive MR inhibitors

42

Mechanism of action of triamterene/amiloride?

Block the ENaC channel

43

Clinical use of K sparring diuretics

Hyperaldosteronism
K depletion
HF (even without frank edema can be useful to decrease aldosterone and its fibrotic action on the heart)
Ca based nephrolithiasis

44

Toxicity of K sparring diuretics?

Hyperkalemia (arrythmia)
Hyperchloremia acidosis
Spirnolactone can have actions on other endocrine receptors causing gynocomastia (testosterone) and other anti-androgenic effects

45

What are the mechanisms of action of ACE inhibitors?

Block ACE which converts ANGI to ANGII and metabolizes bradykinin into inactive metabolites

46

Clinical uses of Ace inhibitors?

HT
HF
Proteinuria
Diabetic nephropathy (decreases constriction of efferent arteriole caused by NEG, decreased intraglomerular pressure slowing GBM thickening and mesangial expansion)
Prevent unfavorable heart remodeling

47

What are the toxicities of ACE inhibitors?

CATCHH
Cough (bradykinin)
Angioedema
Teratogen (renal malformations)
Increase Creatinine (decrease in GFR)
Hyperkalemia
Hypotension

48

When are ACE inhibitor counterindicated?

Cl esterase deficiency
Bilateral renal artery stenosis (decrease GFR)

49

What is the mechanism for ARBs?

Block the binding of ang II to ATI Rs (Gq)

50

Clinical use of ARBs?

HT
HF
Proteinuria
Diabetic nephropathy with intolerance to ACE inhibitors (angioedema, cough)

51

Toxicities of ARBs?

Teratogen
Increase CK
Hypotension
Hyperkalemia
Decrease renal function

52

Mechanism of action of aliskiren?

binds and inhibits the action of renin

53

What is the clinical use of aliskiren?

HT

54

What is the toxicity of aliskiren?

Hyperkalemia
Decreased renal function
Hypotention

55

When is aliskiren counterindicated?

Diabetics taking ACEs or ARBs

56

What are weak acid drugs that are excreted by alkalinization of the urine?

aspirin, phenobarbitol, methotrexate, and TCAs

57

What are weak bases that are improved by acidification of the urine?

amphetamines

58

What drugs cause DI?

lithium, demecocycline

59

What drugs cause Fanconi syndrome?

Expired tetracycline

60

Hemorrhagic cystitis is caused by which drugs?

cyclophosphamide, ifosfamide

61

Interstitial nephritis is caused by which drugs?

Methicillin, furosemide, and NSAIDs

62

What can you administer with cyclophosphomide to prevent hemorrhagic cystitis?

mesna

63

What drugs cause SIADH?

carbamazipine
Cyclophosphomide
SSRIs
Can't concentrate Serum sodium

64

Pentad for TTP?

FAT RN
Fever
Anemia
Thrombocytopenia
Renal failure
Neurological issues

65

What is the test for citrate stones?

sodium cyanide nitroprusside +
break disulfide bonds to release cysteine