Fluid and Electrolyte Replacement

Question 1

CM in volume depletion with 5% loss

Answer 1

thirst, dry mucous membranes

Question 2

CM in volume depletion with 10% loss

Answer 2

tachycardia, oliguria

Question 3

CM in volume depletion with 15-20% loss

Answer 3

hypotension, tachycardia, narrow pulse pressure

Question 4

what is most sensitive indicator for volume loss?

Answer 4

heart rate- tachycardia

Question 5

patient that is hypernatremic. You give fluids to get sodium level down. What is a good guideline for changing sodium levels?

Answer 5

do not change sodium levels more than 12 mOsm/24 hours

Question 6

Types of volume depletion

Answer 6

water deficit with or without solute deficit

Question 7

water deficit without solute deficit. Tx for calculating change in total body sodium

Answer 7

change in sodium = (140 - Patient’s Na level) X TBW (or wt. in kg x 0.6)

Question 8

what fluid to use in hypernatremic patient that is stable and non-hypotensive?

Answer 8

D5W

Question 9

what fluid to use in hypernatremic patient that is hypotensive?

Answer 9

use hypotonic soln (but will require more of it)

Question 10

Tx in patient in hypovolemic shock

Answer 10

20 ml/kg bolus NS, then repeat bolus of 10-20 ml/kg until systolic pressure above 80 mmHg

Question 11

Tx in patient with volume depletion from diuretic loss. Not in hypovolemic shock.

Answer 11

1 L NS over first hour, then 500-1000 ml NS second hour OR 10 ml/kg for every 1% dehydration. half given over 8 hours, remaining half given over 16 hours

Question 12

Tx mild volume overload

Answer 12

Na restriction to less than 2 g Na/day (CHF patients)

Question 13

tx severe volume overload

Answer 13

diuretic (lasix)

Question 14

Hyponatremia tx if sodium more than 125 mEq/L

Answer 14

water restrict

Question 15

Hyponatremia tx if sodium less than 125 mEq/L

Answer 15

Diuretics

Question 16

In hyponatremia, should you correct all of the sodium deficit?

Answer 16

No, only half because also water restriting, using diuretics

Question 17

equation for calcuting sodium deficit in hyponatremia

Answer 17

Na deficit per L= desired sodium - patients sodium. Total sodium deficit is that value x TBW

Question 18

at what rate do you correct sodium deficit?

Answer 18

replace at 0.5 mEq/hr

Question 19

how much sodium in 1.8% Nacl?

Answer 19

300 meq/l

Question 20

how much sodium in 3% nacl?

Answer 20

513 meq/L

Question 21

effect of potassium in acidic environment?

Answer 21

H ions will go into cells, and potassium will get kicked out, resulting in INCREASED levels- inc excitability of cells

Question 22

EKG in hypokalemia

Answer 22

prolonged PR interval, new wave after T

Question 23

EKG in hyperkalemia

Answer 23

prolonged PR interval, widened QRS, tall peaked T waves, sine waves

Question 24

most feared consequence of hyperkalemia

Answer 24

life threatning arrhythmias- PEA, asystole

Question 25

fake causes of hyperkalemia

Answer 25

Hemolysis, potassium infusion, check CBC- infection causing shifting of ions out of the cell

Question 26

EMERGENCY Rx Hyperkalemia

Answer 26

1-2, 10 ml ampules of 10% calcium gluconate over 2-5 minutes. also, Give 10U Regular Insulin IV push with 1 ampule D50 IV push. can also give albuterol, sodium bicarbonate, lasix (caution)

Question 27

Non emergent Tx hyperkalemia (if have more time to correct)

Answer 27

Kayexelate 30-60 gm PO (sodium polystyrene sulfonate)

Question 28

dangerous consequences of hypokalemia

Answer 28

arrhythmia, paralysis, rhabdomyolysis

Question 29

refeeding syndrome can result in what electrolyte abnormalities?

Answer 29

hypokalemia, hypophasphatemia, hypomagnesemia, and sometiems hypoglycemia

Question 30

refeeding syndrome triggered by

Answer 30

intense insulin secretion

Question 31

estimating K deficit

Answer 31

For every 100 mEq below normal, serum K drops by 0.3 mEq/L. Or for every 10 mEq below normal, serum K drops by 0.1 mEq

Question 32

after calculating K deficit in hypokalemia, what route do you choose to replace?

Answer 32

ORAL preferred- quicker, less SE, less dangerous

Question 33

In what situations do you choose IV K replacement in hypokalemic patients?

Answer 33

If NPO or have severe depletion, K at 2.7 or less. complete heart block

Question 34

preferred agent in hypokalemia replacement

Answer 34

KCL oral 60-80 meq

Question 35

replacing K in DKA patients

Answer 35

potassium phosphate

Question 36

replacing K in metabolic acidosis

Answer 36

potassium acetate, bicarbonate, citrate, or gluconate

Question 37

You decide to use IV KCL to restore potassium in your severely volume depleted patient. You do a "Piggyback" with 40-60 mEq K. What solution do you AVOID?

Answer 37

dextrose- triggers insulin, which causes K into cells. Use NS

Question 38

Lidocaine IV- caution

Answer 38

can cause arrhythmias so caution

Question 39

Lidocaine IV benefit

Answer 39

prevents phlebitis

Question 40

Severe hypokalemia patient. You decide to use combination of oral and IV. What doses/rates are used?

Answer 40

KCl PO 60-80 mEq BID or TID. KCl IV 10 mEq/hr

Question 41

gentle vs. aggressive tx in hypokalemic patients

Answer 41

DKA and IV diuretic patients- AGGRESSIVE. keep K above 4-4.5 in cardiac patients. Gentle in acute or chronic renal failure patients

Question 42

always check this electrolyte in cases of refractory hypokalemia

Answer 42

MAGNESIUM!

Question 43

Acidosis effect on calcium

Answer 43

increases free calcium

Question 44

alkalosis effect on calcium

Answer 44

more bound calcium (decreaesd free calcium). proteins give off H ions and bind calcium

Question 45

tx in hypocalcemia is only indicated in symptomatic patients. IV avoided.

Answer 45

1-3 grams of Calcium chloride depending on serum ionized calcium level

Question 46

tx in symptomatic patient (fatigue, weakness, kidney stones) with serum calcium level of 13 mg/dL

Answer 46

Hypercalcemia- NS 300-500 ml/hour, tapering to 200-250 ml/hr

Question 47

Hypercalcemic patient with level greater than 16 mg/dL tx:

Answer 47

NS load, calcitonin to promote osteoblasts to build bone, and bisphosphonates to prevent breakdown of bone

Question 48

Chvostek's sign, Trousseau's sign think

Answer 48

hypocalcemia

Question 49

Claudin-19

Answer 49

tight junction protein that allows for Mg and Ca reabsorption in kidney

Question 50

Mg is reabsorbed in ..

Answer 50

thick ascending loop of henle by passive diffusion based on sodium reabsorption. claudin-16 also plays a role in its reabsoption

Question 51

What 3 factors decrease Mg reabsorption

Answer 51

Increased plasma calcium, decreased pH, and low potassium

Question 52

food sources magnesium

Answer 52

green vegetables, legumes( beans and peas), nuts and seeds, unrefined grains, tap water