Electrolyte Abnormalities review

Question 1

what fluid do you NOT use in hypercalcemic crisis

Answer 1

• lactated Ringers…has calcium in it

Question 2

what are the electrolyte abnormalities of refeeding syndrome?

Answer 2

• hypophosphatemia (this is what causes respiratory compromise)
• hypokalemia
• hypomagnesia

Question 3

diplopia
dysphagia 
confusion
cardiac arrhythmia
respiratory muscle weakness

what is the electrolyte abnormality

Answer 3

hypophosphtemia

• key is the cardiac dysfunction and respiratory compromise (don’t have ATP)

Question 4

patient with hypocalcemia refractory to IV supplementation

what should you check and potentially fix

Answer 4

check magnesium level, hypomagensia causes refractory hypocalcemia

Question 5

Vitamin A deficiency leads to?

Answer 5

• Xeropthalmia (dry eyes)

- rashes

Question 6

Vitamin D deficiency leads to?

Answer 6

hypophosphatemia

hypocalcemia

Question 7

Vitamin K deficiency leads to

Answer 7

elevated INR

coagulopathy

Question 8

Vitamin E deficiency leads to?

Answer 8

• hemolytic anemia

- neuromuscular disorders

Question 9

what kind of metabolic and electrolyte abnormalities would you expect from high NGT output?

Answer 9

• mimics vomiting -> metabolic alkalosis with hypernatremia (body’s attempt to retain sodium/water)

Question 10

daily calorie requirement?

Answer 10

25-30 kcal/kg

Question 11

daily calorie requirement for patients under stress

Answer 11

35-40 kcal/kg

Question 12

daily fluid requirement

Answer 12

30 mL/kg

Question 13

daily sodium requirement

Answer 13

2 mEq/kg

Question 14

daily potassium requirement

Answer 14

1 mEq/kg

Question 15

how do you calculate nitrogen balance?

Answer 15

Nitrogen balance (g) = protein intake (g) / 6.25 - (UUN - 4)

UUN = urinary ura nitrogen

if you use TUN (total urea nitrogen) then its TUN - 2

Question 16

Why do alcoholics suffer from anion-gap metabolic acidosis?

Answer 16

Thiamine deficiency resulting in beri-beri

Question 17

equation for sodium deficit?

Answer 17

desired Na level - current Na level x TBW

TBW in men = 0.6
TBW in women = 0.5

Question 18

what is the rate of correction for hyponatremia

Answer 18

6-12 mEq/day

Question 19

What does large volume resuscitation with NS result in?

Answer 19

Non-anion gap hyperchloremic metabolic acidosis

Question 20

Trouseau sign

Answer 20

cardopedal spasm after BP cuff inflation, sign of hypocalcemia

Question 21

cardopedal spasm after BP cuff inflation

Answer 21

Trouseau sign = hypocalcemia

Question 22

numbness around the mouth, what is it a sign for with electrolyte abnormalities

Answer 22

hypocalcemia

Question 23

Chvostek Sign

Answer 23

twitching of cheek after tapping parotid nerve = hypocalcemia

Question 24

twitching of cheek after tapping parotid nerve

Answer 24

Chvotsek sign = hypocalcemia

Question 25

caloric content of oral carbohydrates

Answer 25

4 cal/gram

Question 26

caloric content of sugar infusions used in TPN

Answer 26

3. 4 cal/gram

- .-

Question 27

how does anti-diuretic hormone work?

Answer 27

acts on V2 receptor to induce aquaporin integration at the collecting ducts

• net effect is concentration of urine

Question 28

how does diabetes insipidus work?

Answer 28

TBI causes decrease in ADH release, therefore V2 is not activated and aquaporins are NOT placed onto collecting ducts

• net effect is that urine cannot be concentrated

Question 29

what do you check for refractory hypokalemia

Answer 29

magnesium level, may need to be replaced

Question 30

what does lithium toxicity cause?

Answer 30

• hypercalcemia

- hypermagnesium

Question 31

how do you treat asymptomatic euvolemic/hypervolemic hyponatremia?

Answer 31

• fluid restriction and observation

Question 32

3 most common causes of non-anion gap metabolic acidosis

Answer 32

• IV infusion
• renal tubular acidosis
• GI losses: diarrhea, high ostomy output, high fistula output

Question 33

How do you calculate serum osmolality

Answer 33

= (2 x sodium) + (glucose/18 + BUN/2.8)

Question 34

what is the rule of sixes for severe hyponatremia

Answer 34

6 mEq correction in every 6 hours