Electrolytes

Question 1

which electrolyte alteration is an independent risk factor for death?

Answer 1

hyponatremia

Question 2

if Mg is deficient replacement of what ion is refractory?

Answer 2

K+

Question 3

for pt who is waiting for surgery, what replacement fluid do you give?

Answer 3

hypertonic saline = .45NS + glucose … 77mEQ Na

Question 4

calc for Sosm?

Answer 4

2Na + Gluc/18 + BUN/2.8

Question 5

Calc for FENA

Answer 5

(UNA/SNA) / (UCR / SCR)

Question 6

K replacement is refractory if what ion is deficient?

Answer 6

magnesium

Question 7

5 causes of euvolemic hyponatremia

Answer 7

1. SIADH
2. Meds (opiates, thiazides)
3. Hypothyroidism
4. Adrenal insufficiency
5. dec solute intake (beer potomania and tea/toast diet)

Question 8

thiazide effect on electrolytes, thirst, and urine dilution

Answer 8

dec Na and K
inc thirst
impair urine dilution

Question 9

causes of SIADH

Answer 9

cancer
CNS dz
drugs
pulm issue
post-op
pain 
HIV

Question 10

value for Urine osms in euvolemic hyponatremia

Answer 10

low urine osm

Question 11

hypovolemic hyponatremia can be divided into what 2 issues

Answer 11

renal or extra-renal loss of Na

Question 12

4 causes of renal Na loss giving hypovolemic hyponatremia

Answer 12

1. diuretics
2. osmotic diuresis (glucose, urea, mannitol)
3. adrenal insufficiency or mineralocorticoid
4. cerebral salt wasting

Question 13

3 causes of extra-renal na loss giving hypovolemic hyponatremia

Answer 13

1. N/V/D or excess sweating
2. blood loss
3. 3rd spacing (trauma, burns, bowel obstruction, pancreatitis)

Question 14

urine na and FENA values for renal causes

Answer 14

urine sodium > 20 with FENA > 1 for renal

Question 15

urine na and FENA for extra-renal causes

Answer 15

urine sodium < 20 with FENA < 1 for extra-renal

Question 16

for hypovolemic hyponatremia there’s dec volume of intracellular or extracellular fluid

Answer 16

extracellular

Question 17

5 causes of hypervolemic hyponatremia

Answer 17

1. pregnancy
2. nephrotic
3. cirrhosis
4. CHF
5. renal failure

Question 18

causes of hyponatremia secondary to inc water intake

Answer 18

primary polydipsia or dilute infant formula

Question 19

tx for hyponatremia

Answer 19

fluid restriction

inc Na no more than 6mEq/L per 24 hrs

Question 20

cause of hyponatremia in AIDs pt

Answer 20

SIADH

Question 21

urine sodium for SIADH vs dehydration

Answer 21

SIADH Urine na> 40

Dehydration Urine na < 20

Question 22

when do you use bicarb for hyponatremia

Answer 22

QRS prolongation

severe metabolic acidosis (pH < 6.9)

Question 23

Lasix effect on K+ and acid base status

Answer 23

low k
low cl
metabolic alkalosis

Question 24

thiazide effect on k+ and acid base status

Answer 24

low k
metabolic alkalosis (inc renal loss of k and H)

Question 25

max rate for iv replacement of K? if via central line?

Answer 25

max 10mEq/L/hr

if central line, max 20mEq/L/hr

Question 26

sxs of inc calcium

Answer 26

Altered mental status

Question 27

hypercalcemia > 15 effect on kidney

Answer 27

dec vasopressin receptors, get nephrogenic DI, lose free water, leads to inc calcium in blood

Question 28

tx of hypercalcemia > 14

Answer 28

isotonic crystalloid fluid to volume expand

Question 29

tx of pt with rhabdo who has impaired renal fxn?

Answer 29

urinary alkalinization
IV fluids
sodium bicarb
mannitol/lasix
*i think this is the answer*