Electrolyte Abnormalities review Flashcards
what fluid do you NOT use in hypercalcemic crisis
- lactated Ringers…has calcium in it
what are the electrolyte abnormalities of refeeding syndrome?
- hypophosphatemia (this is what causes respiratory compromise)
- hypokalemia
- hypomagnesia
diplopia dysphagia confusion cardiac arrhythmia respiratory muscle weakness
what is the electrolyte abnormality
hypophosphtemia
- key is the cardiac dysfunction and respiratory compromise (don’t have ATP)
patient with hypocalcemia refractory to IV supplementation
what should you check and potentially fix
check magnesium level, hypomagensia causes refractory hypocalcemia
Vitamin A deficiency leads to?
- Xeropthalmia (dry eyes)
- rashes
Vitamin D deficiency leads to?
hypophosphatemia
hypocalcemia
Vitamin K deficiency leads to
elevated INR
coagulopathy
Vitamin E deficiency leads to?
- hemolytic anemia
- neuromuscular disorders
what kind of metabolic and electrolyte abnormalities would you expect from high NGT output?
- mimics vomiting -> metabolic alkalosis with hypernatremia (body’s attempt to retain sodium/water)
daily calorie requirement?
25-30 kcal/kg
daily calorie requirement for patients under stress
35-40 kcal/kg
daily fluid requirement
30 mL/kg
daily sodium requirement
2 mEq/kg
daily potassium requirement
1 mEq/kg
how do you calculate nitrogen balance?
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
Why do alcoholics suffer from anion-gap metabolic acidosis?
Thiamine deficiency resulting in beri-beri
equation for sodium deficit?
desired Na level - current Na level x TBW
TBW in men = 0.6
TBW in women = 0.5
what is the rate of correction for hyponatremia
6-12 mEq/day
What does large volume resuscitation with NS result in?
Non-anion gap hyperchloremic metabolic acidosis
Trouseau sign
cardopedal spasm after BP cuff inflation, sign of hypocalcemia
cardopedal spasm after BP cuff inflation
Trouseau sign = hypocalcemia
numbness around the mouth, what is it a sign for with electrolyte abnormalities
hypocalcemia
Chvostek Sign
twitching of cheek after tapping parotid nerve = hypocalcemia
twitching of cheek after tapping parotid nerve
Chvotsek sign = hypocalcemia
caloric content of oral carbohydrates
4 cal/gram
caloric content of sugar infusions used in TPN
- 4 cal/gram
- .-
how does anti-diuretic hormone work?
acts on V2 receptor to induce aquaporin integration at the collecting ducts
- net effect is concentration of urine
how does diabetes insipidus work?
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
what do you check for refractory hypokalemia
magnesium level, may need to be replaced
what does lithium toxicity cause?
- hypercalcemia
- hypermagnesium
how do you treat asymptomatic euvolemic/hypervolemic hyponatremia?
- fluid restriction and observation
3 most common causes of non-anion gap metabolic acidosis
- IV infusion
- renal tubular acidosis
- GI losses: diarrhea, high ostomy output, high fistula output
How do you calculate serum osmolality
= (2 x sodium) + (glucose/18 + BUN/2.8)
what is the rule of sixes for severe hyponatremia
6 mEq correction in every 6 hours
