FEN

Question 1

what is the 60-40-20 rule?

Answer 1

60% of body weight is water,
40% is ICF,
20% is ECF (5% plasma, 15% ISF)

Question 2

what are the Starling forces?

Answer 2

hydrostatic pressure drives fluid into ICF, oncotic pressure sucks it back out

Question 3

how is blood osmolarity calculated? what is a normal value?

Answer 3

2×Na + BUN/2.8 + gluc/18

normally 285-300 mOsm/L

Question 4

what is normal urine osm? what controlls this?

Answer 4

70-1200 mOsm/L

controlled by ADH

Question 5

fluids to give to:

• dehydrated
• trauma
• std maintenance
• hypernatremic

Answer 5

NS: good for dehydrated pts
LR: good for trauma pts
D5½NS: standard maintenance fluid
D5W: good for hypernatremic pts

Question 6

how to calculatd MIVF for 24 hrs
vs
1 hr

Answer 6

100-50-20 rule: maintenance fluids for 24 hrs
100 mL/kg for first 10 kg, then 50 for next 10 kg, then 20 for each kg over

4-2-1 rule: maintenance fluids for 1 hr
4 mL/kg for first 10 kg, then 2 for next 10 kg, then 1 for each kg over

Question 7

causes water reabsorption (V2, aquaporins) and vasoconstriction (V1)

Answer 7

ADH

Question 8

aldo effect on electrolytes

Answer 8

↑Na, ↓K, ↓H

Question 9

PTH effect on electrolytes

Answer 9

↑Ca, ↓P, ↑vit D

Question 10

calcitonin effect on electrolytes

Answer 10

↓Ca, ↓P

Question 11

effect of Vit D

Answer 11

↑Ca, ↑P

Question 12

what causes hypernatremia?

tx?

Answer 12

water loss due to 6 Ds –
Diuresis, Dehydration, Diabetes insipidus, Docs (iatrogenic), Diarrhea,
Diseases

Tx PO fluids > IV fluids (correct gradually due to risk of cerebral edema)

Question 13

MCC hyponatremia

management

Answer 13

SIADH

Tx water restriction + NS (correct gradually due to risk of central pontine myelinolysis)

Question 14

etiologies of hyperK

management?

Answer 14

renal failure
K-sparing diuretics
release from dead tissue (crush injury, ischemic bowel, etc.)

• first, confirm w/ repeat blood draw
• Dx EKG (peaked T waves, sine waves)
• Tx C BIG K DIE – calcium gluconate, bicarb insulin-glucose, kayexalate, dialysis (if severe)

Question 15

etiologies of hypoK

management?

Answer 15

diarrhea, vomiting, diuretics

KCl (<10 mEq/hr)
*give 10mEq per 0.1 inc

Question 16

etiologies of hyperCa

management?

Answer 16

hyperparathyroidism (MCC outpt), cancer (MCC inpt)

get EKG (short QT)
• Tx “flush and drain” (NS + furosemide), bisphosphonates if mild

Question 17

etiologies of hyperMg

management?

Answer 17

renal failure

Tx IV calcium gluconate + NS + furosemide

Question 18

etiologies of hypoMg

management?

Answer 18

alcoholism (MCC), DKA

Tx mag replacement

Question 19

etiologies of hyperPO4?

management?

Answer 19

renal failure

tx: antacids (binds PO4 in GI tract)

Question 20

etiologies of hypoPO4?

management

Answer 20

alcoholism (MCC), DKA

phos replacement

Question 21

nausea/vomiting, intestinal colic, weakness

Answer 21

hyper K

Question 22

stones (kidney), bones (bone pain, osteitis fibrosa cystica), groans (PUD,
pancreatitis), psychic overtones (depression, anxiety, ∆MS)

Answer 22

hyperCa

Question 23

confusion, coma, convulsions

Answer 23

hypo Na

Question 24

delirium, ↓DTRs, cardiac arrest

Answer 24

hyperMg

Question 25

rickets, osteomalacia

Answer 25

hypoPhos

Question 26

thirst and signs of volume depletion (slow) or ∆MS (rapid)

Answer 26

hyperNa

Question 27

weakness, muscle cramps, ileus, digoxin toxicity

Answer 27

hypoK **(K and dig compete for same Na/K receptors on heart)

Question 28

neuromuscular irritability (tingling, tetany), arrhythmias, Chvostek and Trousseau signs

Answer 28

hypoCa

Question 29

refractory hypo-K

Answer 29

hypoMg

Question 30

kidney stones, metastatic calcifications

Answer 30

hyperPhos

Question 31

EKG showing short QT vs long QT What electrolyte imbalance?

Answer 31

short QT = hyperCa | long QT = hypo Ca

Question 32

EKG changes assc with hyperK and hypoK

Answer 32

``` hyperK = peaked T waves, sine waves hypoK = scooped/depressed T waves ```

Question 33

how to calculate anion gap? nml anion gap?

Answer 33

(Na – (Cl + HCO3)) nl 8-12

Question 34

causes of respiratry acidosis

Answer 34

hypoventialtion

Question 35

causes of respiratory alkalosis

Answer 35

hyerventialtion (pain, fever, sepsis, early ARDS)

Question 36

Causes on anion gap metabolic acidosis

Answer 36

MUDPILES – Methanol, Uremia, DKA, Paraldehyde, Iron, INH, Lactic acidosis, Ethylene glycol, Salicylates

Question 37

causes on non-anion gap metabolic acidosis

Answer 37

diarrhea, glue sniffing, RTA, hyperchloremia

Question 38

causes of metabolic alkalosis

Answer 38

vomiting, diuretics, antacids, hyperaldosteronism

Question 39

how much does pH change for every inc in CO2 by 10

Answer 39

dec 0.08

Question 40

how much does pH change for every inc in HCO3 by 10

Answer 40

inc 0.15

Question 41

post ictal state, what acid-base balace expect, management?

Answer 41

anion gap metabolic acidosis will usually resolve in its own in 60-90 mins

Question 42

acid-base assc with aspirin overdose

Answer 42

early: hyperventialtion w/ resp alk late: metabolic acidosis **expect tinnitus and fever

Question 43

what acid-base imbalance a/w iron overload

Answer 43

anion gap met acidosis **expect abd pain, UGIB