Fluids, Electrolytes, Renal

Question 1

Total body and water and extracellular fluid ______ with increasing gestational age

Answer 1

Decrease

Question 2

At what age does intracellular fluid begin to make up a larger part of total body water

Answer 2

Around three months of age

Question 3

What percent of body weight is total body water at 24 weeks and at term

Answer 3

90% at 24 weeks gestation and 80% at term delivery

Question 4

How to correct freewater deficit

Answer 4

Administer four mL/kilo of free water for everyone mEq per liter increase in sodium over 145

Question 5

When is ADH present in the fetus?

Answer 5

11 weeks gestation

Question 6

Calculation of plasma osmolality

Answer 6

(2 x plasma sodium) + (glucose mg/dL/18) + (BUN/2.8)

Question 7

Genetics of congenital nephrogenic diabetes insipidus

Answer 7

X-linked recessive for the vasopressin receptor defect, and autosomal for the Aquaporin defect

Question 8

Management of nephrogenic diabetes insipidus

Answer 8

Hydrate, monitor electrolytes, thiazides to increase urine concentrating ability (potassium supplementation as needed.)

Question 9

Correction of sodium for high glucose

Answer 9

Sodium is decreased by 1.6 mEq/L for each 100 increase in glucose (pseduohyponatremia)

So to calculate= Measured Na + (glucose -100) x 0.016

Question 10

Calculation of sodium deficit

Answer 10

[Na desired- Na current] x 0.6 x weight (kg)

Question 11

Where does most of bicarbonate reabsorption occur?

Answer 11

60 to 80% occurs in the proximal tubule

Question 12

Net acid excretion in the urine equals

Answer 12

(Titratable acids + ammonium) - non-reabsorbed bicarbonate

Question 13

Where does acidification of the urine occur?

Answer 13

Cortical and medullary collecting tubule cells

Question 14

Calculation of anion gap

Answer 14

Na - (chloride + bicarb)

Question 15

Calculation of bicarb replacement

Answer 15

0.3 x bicarb deficit x weight

Question 16

Problem in type I RTA

Answer 16

Can’t secrete H+ in distal tubule

Question 17

Problem in type II RTA

Answer 17

Decreased or absent proximal tubule bicarb reabsoprtion

Question 18

Dehydration, failure to thrive, normal blood pressure, nephrocalcinosis, polyuria, normal serum calcium

Answer 18

Barrter syndrome

Question 19

Management of Bartter syndrome

Answer 19

Potassium supplementation, +/- thiazide diuretics, +/-indomethacin

Question 20

When are first nephrons formed

Answer 20

8 weeks gestation

Question 21

When does urine production start

Answer 21

10-12 weeks gestation

Question 22

The preterm infant has recused ability to contrite urine due to:

Answer 22

1. Tubule insensitivity to vasopressin
2. Short loop of henle
3. Low osmolality of medullary interstitium (secondary to limited Na reabsorption in thick ascending loop)
4. Low serum urea

Question 23

Calculation of fractional excretion of sodium

Answer 23

(Urine sodium x plasma creatinine) / (urine creatinine x plasma sodium) x100

<1% normal; 1-2.5% pre-renal; >3% intrinsic renal failure

Question 24

Where is potassium reabsorbed/secreted?

Answer 24

Reabsorbed proximal tubule and ascending loop of Henle
Secreted in distal tubule and collecting ducts

Question 25

Where is sodium reabsorbed in kidney

Answer 25

2/3 in proximal tubule 20% in ascending loop of Henle 10% in distal tubule/collecting duct

Question 26

Where is reabsorption of Calcium in kidney

Answer 26

Proximal tubule and loop of Henle by passive movement, limited by sodium Distal tubule and collecting ducts (active)

Question 27

Calculation of tubular reabsorption of phosphorus

Answer 27

1- [(urine phosphorus x plasma creatinine) / (urine creatinine x plasma phosphorus)]

Question 28

Where is phosphorus reabsorbed

Answer 28

80% in proximal tubule, 10% in distal tubule, remaining excreted

Question 29

Genetics and pathogenesis of pseudohypoaldosteronism

Answer 29

X-linked recessive Unresponsiveness of renal tubule to aldosterone

Question 30

Lab findings in pseudohypoaldosteronism

Answer 30

Low sodium, high potassium, metabolic acidosis, increased aldosterone, increased renin

Question 31

Estimated GFR formula

Answer 31

(0.45 x height)/ plasma creatinine

Question 32

Creatinine clearance calculation

Answer 32

(Urine creatinine x volume) / plasma creatinine

Question 33

Where is most protein reabsorbed in kidney

Answer 33

Proximal tubule

Question 34

What is the injury if you see leukocytouria in the urine?

Answer 34

UTI, obstructive uropathy, or glomerulonephritis

Question 35

What is the injury if you see red blood cell casts in the urine?

Answer 35

Glomerular injury

Question 36

What is the injury if you see white blood cell casts in the urine?

Answer 36

Infection, renal interstitial/tubular injury

Question 37

What is the injury if you see epithelial/granular casts in the urine?

Answer 37

Dehydration or renal interstitial/tubular injury

Question 38

What is the injury if you see hyaline casts in the urine?

Answer 38

Severe proteinuria, dehydration

Question 39

Proteinuria, hypoproteinemia, hyperlipidemia, and edema

Answer 39

Congenital nephrotic syndrome

Question 40

Genetics of Finnish congenital nephrotic syndrome

Answer 40

Autosomal recessive on chromosome 19, 19q13.1, gene NPHS1, gene product is called nephrin

Question 41

Gene and chromosome in autosomal recessive PKD

Answer 41

Chromosome 6p21, PKHD1, which encodes fibrocystin/polyductin-expressed on cilia of renal cells and bile duct cells

Question 42

Gene and chromosome in autosomal dominant PKD

Answer 42

Chromosome 16 (a few on 4p)

Question 43

Fanconi syndrome

Answer 43

Proximal tubule dysfunction, leading to excess urinary losses of amino acids, glucose, phosphate, and bicarbonate

Question 44

Management of Fanconi syndrome

Answer 44

Supplement with sodium phosphate, sodium and potassium citrate, and vitamin D

Question 45

Genetics of Fanconi syndrome

Answer 45

Autosomal dominant but generally sporadic

Question 46

What is cystinosis?

Answer 46

Defective carrier-mediated transport of cysteine leading to excess cysteine in lysosomes of many cells

Question 47

Diagnosis and management of cystinosis

Answer 47

Diagnosed with cornea lamp exam demonstrating cystine crystals, and management is with cysteamine and renal transplant

Question 48

Genetics and pathogenesis of lowe syndrome

Answer 48

X-linked recessive, gene defect leads to an enzyme deficiency disrupting, the Golgi apparatus

Question 49

Cataracts, glaucoma, mental deficiency, muscular hypotonia, renal, tubular, dysfunction, proteinuria, cryptorchidism

Answer 49

Lowe syndrome

Question 50

The recessive form of type I RTA can be associated with what?

Answer 50

Hearing loss

Question 51

Calculation of free water deficit

Answer 51

4 mL x weight x (desired change in serum Na)

Question 52

Modalities of continuous renal replacement therapy, that incorporate hemofiltration use the principle of what to remove solutes

Answer 52

Convection

Question 53

Slow continuous ultra filtration is useful for what

Answer 53

To remove fluid in patients with volume overload, but it will not correct acidosis electrolyte, anomalies or uremia, because the low ultra filtration rate has minimal solvent drag they are for trivial amounts of solutes are removed from plasma

Question 54

In cvvhd how are solutes removed

Answer 54

By diffusion across the concentration gradient

Question 55

Is CVVHD or CVVH more likely to remove low molecular weight solutes

Answer 55

CVVHD (But is less likely to remove high molecular weight solutes, and water)

Question 56

Primary brain energy substrate during periods of hypoglycemia

Answer 56

Lactate