nutrition support

Question 1

What is parenteral nutrition?

Answer 1

nutrition given via venous access (enteral = GI, para = around - so not in GI, around GI => blood)

Question 2

What is enteral nutrition?

Answer 2

tube feed (via GI)

Question 3

When is enteral nutrition indicated?

Answer 3

when oral intake is insufficient or counterindicated,
always preferred over parenteral b/c less risk of infection, cheaper, prevents gallstones by stimulating gallbladder motility, prevents atrophy of gut and pancreas

Question 4

types of enteral feeds?

Answer 4

nasogastric, nasojejunal (NJ), percutaneous endoscopic gastrostomy (G-tube via skin incision), percutaneous endoscopic jejunostomy (J-tube)

Question 5

what is polymeric feed?

Answer 5

whole proteins + carbs + fats as liquids (+/- fibre)

polymer = multiple = food not broken down into elemental pieces

Question 6

what is elemental feed?

Answer 6

food broken down into small pieces: proteins broken to aas, carbs into simple sugars, few fats

Question 7

contraindications?

Answer 7

non-functioning gut (no use giving food if it will not be absorbed)
uncontrolled diarrhea (same)
GI bleed - risk of infection!

Question 8

complications to enteral feed?

Answer 8

aspiration
refeeding syndrome
overfeeding syndrome
infection/sepsis

Question 9

when is parenteral nutrition indicated?

Answer 9

IV, when patient expected to have non-functioning gut for >7 days
need to be able to tolerate large fluid volumes in blood (hemodynamically and metabolically stable!)

Question 10

counterindications to parenteral nutrition?

Answer 10

if GI functional, give enteral not parenteral
active infection - risk of making it worse, push antibiotics first
hemodynamic instability

Question 11

complications of parenteral nutrition?

Answer 11

sepsis
pneumothorax from insertion of central line, catheter migration, thrombosis, etc
metabolic: CHF (volume overload), hyperglycemia (pushing directly into blood, harder to control levels), gallstones (gallbladder immobile), chelestasis (same reason)

Question 12

what is refeeding syndrome?

Answer 12

potentially life threatening response to refeeding severely malnourished patient resulting in severe shifts in fluids and electrolytes

Question 13

what is marasmus

Answer 13

decrease in protein and energy intake (dec. body fat, muscle wasting)
give proteins and calories

Question 14

what is kwashiorkor

Answer 14

decrease in protein intake only, ok body fat, atrophied muscle
give proteins only

Question 15

most common indications for nutritional support?

Answer 15

1. pre-existing nutritional deprivation
2. inadequate E intake by mouth
3. significant multiorgan systme disease

Question 16

BMI range that is healthy?

Answer 16

18.5 - 24.9 - normal
25 - overweight
30 - obese

(weight (kg) / height 2 (m2)

Question 17

cause of refeeding syndrome?

Answer 17

too many calories too fast in malnourished patients
pathophysiology: shifts of fluid, electrolyte and mineral balance
signs: low serum P, K, Mg and Na, thiamine deficiency, hyperglycemia
within hours of refeeding
consequence: fatigue, lethargy, muscle weakness, dizziness, edema, cardiac/resp failures, death

Question 18

pathophysiology of refeeding syndrome?

Answer 18

chronic malnutrition, prolonged fast -? intracellular minerals like PO4, K, Mg severely depleted - may not be on bloodwork b/c low concentrations in serum (serum {} measured), they are lower intracellularly (thats where the bulk of them lives, but because intracellular content shrinks too, total concentration can still be the same

carbs -> insulin up -> stimulates the absorption of glucose, phosphorus, magnesium and potassium into cells -> hypophosphatemia, hypokalemia, hypomagnesemia, thiamine deficiency, sodium/water retention (b/c glucose is transported into intestine with Na+ (2Na+ for every glucose in to drive absorption), so as glucose absorbed, need Na+ - less Na+ eliminated by kidneys, with more Na+ in body, more water stays in body too - large amounts of ECFV -> refeeding syndrome -> confusions, delirium, arrhythmias, heart failure, renal failure, rhabdomyolysis

arrhythmia is the most common cause of death in refeeding syndrome

Question 19

how do you avoid refeeding syndrome?

Answer 19

start low go slow
correct volume depletion first and monitor renal funciton
supplement with thiamine