nutrition support Flashcards
What is parenteral nutrition?
nutrition given via venous access (enteral = GI, para = around - so not in GI, around GI => blood)
What is enteral nutrition?
tube feed (via GI)
When is enteral nutrition indicated?
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
types of enteral feeds?
nasogastric, nasojejunal (NJ), percutaneous endoscopic gastrostomy (G-tube via skin incision), percutaneous endoscopic jejunostomy (J-tube)
what is polymeric feed?
whole proteins + carbs + fats as liquids (+/- fibre)
polymer = multiple = food not broken down into elemental pieces
what is elemental feed?
food broken down into small pieces: proteins broken to aas, carbs into simple sugars, few fats
contraindications?
non-functioning gut (no use giving food if it will not be absorbed) uncontrolled diarrhea (same) GI bleed - risk of infection!
complications to enteral feed?
aspiration
refeeding syndrome
overfeeding syndrome
infection/sepsis
when is parenteral nutrition indicated?
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!)
counterindications to parenteral nutrition?
if GI functional, give enteral not parenteral
active infection - risk of making it worse, push antibiotics first
hemodynamic instability
complications of parenteral nutrition?
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)
what is refeeding syndrome?
potentially life threatening response to refeeding severely malnourished patient resulting in severe shifts in fluids and electrolytes
what is marasmus
decrease in protein and energy intake (dec. body fat, muscle wasting)
give proteins and calories
what is kwashiorkor
decrease in protein intake only, ok body fat, atrophied muscle
give proteins only
most common indications for nutritional support?
- pre-existing nutritional deprivation
- inadequate E intake by mouth
- significant multiorgan systme disease
BMI range that is healthy?
18.5 - 24.9 - normal
25 - overweight
30 - obese
(weight (kg) / height 2 (m2)
cause of refeeding syndrome?
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
pathophysiology of refeeding syndrome?
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
how do you avoid refeeding syndrome?
start low go slow
correct volume depletion first and monitor renal funciton
supplement with thiamine
