Fiser ABSITE Ch. 10 Nutrition Flashcards
Caloric need is approximately ___ kcal/kg/day
25
kcal/g of fat, protein, oral carbohydrates, dextrose
9, 4, 4, 3.4
How many g protein/kg/day is needed and what percentage should be essential amino acids.
1, 20
Formula for caloric requirements for burn patient? protein requirements?
25 kcal/kg/day + (30 kcal/day x % burn)
1-1.5 g/kg/day + (3g x % burn)
Much of the energy expenditure is used for what?
heat production
Basal metabolic rate increases ___% for each degree above 38.0
10
What is the name of the equation that calculates basal energy expenditure based on weight, height, age and gender?
Harris-Benedict equation
What is central line TPN based and what is its max administration rate?
glucose, 3 g/kg/hr
What is peripheral line parenteral nutrition (PPN) based?
fat based
What is the fuel for colonocytes?
short chain fatty acids
What is the fuel for small bowel enterocytes?
glutamine
What is the most common amino acid in the bloodstream and tissue?
glutamine
What is the primary fuel for neoplastic cell?
glutamine
Approximate half-life of albumin, transferrin, prealbumin
20 days, 10 days, 2 days
Normal protein level?
6.0-8.5
Name 4 acute indicators of nutritional status
retinal binding protein, prealbumin, transferrin, total lymphocyte count
Formulas for ideal body weight Men and Women
Men 106 lb + 6 lb for each inch over 5 ft
Women 100 lb + 5 lb for each inch over 5 ft
What is the strong risk factor for morbidity and mortality after surgery?
Low albumin (less than 3.0)
What is respiratory quotient?
Ratio of CO2 produced to O2 consumed, measurement of energy expenditure.
What does a RQ > 1 mean? Tx?
lipogenesis (overfeeding)
decrease carbohydrates and caloric intake- high carbohydrate intake can lead to CO2 buildup and ventilator problems
What does a RQ less than 0.7 mean? Tx?
ketosis and fat oxidation (starving)
increase carbohydrates and caloric intake
What is the RQ for pure fat metabolism?
pure protein metabolism?
pure carbohydrate metabolism?
pure fat = 0.7
pure protein = 0.8
pure carbohydrate = 1.0
Postoperative Phases
Diuresis phase days __-__
Catabolic phase days __-__ (negative nitrogen balance)
Anabolic phase days __-__ (positive nitrogen balance)
2-5
0-3
3-6
Glycogen stores are depleted after __-__ hours of starvation. The body then switches to ___
24-36
fat
What proportion is glycogen stores in skeletal muscle and what proportion is in liver?
2/3 in skeletal muscle
1/3 in liver
____ stays in muscle after breakdown from glycogen and is utilized.
Skeletal muscle lacks ____ (found only in the liver)
glucose 6 phosphate
glucose 6 phosphatase
What is the simplest amino acid precursor for gluconeogenesis and the primary substrate for gluconeogenesis
Alanine
What are the only two amino acids to increase during times of stress?
alanine and phenylalanine
Late in starvation gluconeogenesis occurs where?
in the kidney
Protein-conserving mechanisms do not occur after trauma or surgery secondary to what 2 factors?
catecholamines and cortisol
What is the main source of energy in trauma and starvation?
Fat (ketones)
Most patients can tolerate a ___% weight loss without major complications.
15
How many days can a patient tolerate without eating?
After that, what are 2 options?
7 days
Dobbhoff tube or start TPN
What is the main reason to try to feed gut?
avoid bacterial translocation (bacterial overgrowth, increased permeability due to starved enterocytes
What is elemental formula?
all protein given in the form of amino acids (given IV, expensive)
Consider PEG when regular feeding not possible (eg CVA) or predicted not to occur for >___ weeks
4
Brain utilizes ___ with progressive starvation (normally uses glucose)
ketones
Name 4 obligate glucose users
peripheral nerves, adrenal medulla, RBCs and WBCs
What three things are decreased with refeeding syndrome?
K, Mg, PO4
What are the sx of refeeding syndrome?
cardiac dysfunction and fluid shifts
How to prevent refeeding syndrome?
starting at a low rate (10-15/kg/day)
What is cachexia mediated by?
TNF-a
How much protein contains 1 g of nitrogen?
6.25
How much total protein is synthesized in a 70 kg male per day?
250 g/day
What organ is responsible for amino acid production and breakdown?
Liver
What is produced to get rid of ammonia from amino acid breakdown?
urea
The majority of protein breakdown from skeletal muscle is from what two amino acids?
glutamine and alanine
What is used to synthesize bile salts?
cholesterol
How do medium and short chain fatty acids enter enterocytes?
simple diffusion
After micelles and other fatty acids enter enterocytes, what are formed? which enter lymphatics.
chylomicrons
What is the difference between medium/short chain fatty acids and long chain fatty acids in how they enter circulation?
medium and short enter portal system
long chain enter lymphatics
On liver endothelium, clears chylomicrons and TAGs from the blood, breaking them down to fatty acids and glycerol which are then taken up by hepatocyte
Lipoprotein lipase
On liver endothelium; binds short and medium chain fatty acids
Free fatty acid binding protein
Most important route of entry for dietary cholesterol; synthesized in the liver
VLDL
What is the preferred source of energy for the liver, heart and skeletal muscle?
fatty acids
What are unsaturated fatty acids used for?
structural components for cells
In fat cells; breaks down TAGs (storage form of fats) to fatty acids and glycerol; released into blood (sensitive to growth hormone, catecholamines, glucocorticoids)
Hormone-sensitive lipase
What are the 2 essential fatty acids?
linolenic, linoleic
The essential fatty acids are important for immune cells and are needed for ___ synthesis
prostaglandin
Omega 3 fatty acids converted into what three important lipids thought to have antioxidant properties?
PGI3, TXA3, LTB5 (all odd; think BAI)
Omega 6 fatty acids are converted into what 3 important lipids?
PGE2, TXA2, LTB4 (all even; think BAE)
Carbohydrate digestion begins with what enzyme?
Then what other 2?
salivary amylase
then pancreatic amylase and disaccharidases
Glucose and galactose are absorbed by what mechanism? Where are they released into?
secondary active transport
portal vein
Fructose is absorbed by what mechanism? Where is it released into?
facilitated diffusion
portal vein
sucrose = \_\_\_ + \_\_\_ lactose = \_\_\_ + \_\_\_ maltose = \_\_\_ + \_\_\_"
fructose + glucose
galactose + glucose
glucose + glucose
Protein digestion begins with what enzyme?
Then what other 3?
stomach pepsin
trypsin, chymotrypsin and carboxypeptidase
Trypsinogen released from ___ and activated by ___ released from ___.
pancreas, enterokinase, duodenum
What is the mechanism by which protein is aborbed?
Where is it then released and in what form?
amino acids, dipeptides and tripeptides are absorbed by secondary active transport;
released into portal vein as free amino acids
May want to limit protein intake in pts with ___ and ___ to avoid ammonia buildup and possible worsening encephalopathy
liver failure and renal failure
What are the 3 branched amino acids (w/ mnemonic)?
leucine, isoleucine, valine (LIV)
Where are the branched amino acids metabolized?
muscle
Name the deficiency associated with hyperglycemia, encephalopathy, neuropathy
chromium
Name the deficiency associated with cardiomyopathy, weakness, hair loss
selenium
Name the deficiency associated with pancytopenia
copper
Name the deficiency associated with hair loss, poor healing, rash
zinc
Name the deficiency associated with weakness (failure to wean off ventilator), encephalopathy, decreased phagocytosis
phosphate
Name the deficiency associated with Wernicke’s encephalopathy, cardiomyopathy, peripheral neuropathy
Thiamine (B1)
Name the deficiency associated with sideroblastic anemia, glossitis, peripheral neuropathy
Pyridoxine (B6)
Name the deficiency associated with megaloblastic anemia, peripheral neuropathy, beefy tongue
Cobalamin (B12)
Name the deficiency associated with megaloblastic anemia, glossitis
Folate
Name the deficiency associated with pellagra (diarrhea, dermatitis, dementia)
Niacin
Name the deficiency associated with dematitis, hair loss, thrombocytopenia
Essential fatty acids
Name the deficiency associated with night blindness
Vitamin A
Name the deficiency associated with coagulopathy
Vitamin K
Name the deficiency associated with rickets, osteomalacia
Vitamin D
Name the deficiency associated with neuropathy
Vitamin E
What is the process called by which lactate goes to the liver and is converted back to pyruvate and eventually glucose via gluconeogenesis
Cori cycle